Fish - Survival-training.info

AThe Completequarium GuideFISH, PLANTS AND ACCESSORIES FOR YOUR AQUARIUM

© 1995, ATP - Chamalieres - FranceAll rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in anyforms or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permissionof the copyright owners.Original title: Le Grand Guide de I'Aquarium© 2000 for the English edition:Konemann Verlagsgesellschaft mbHBonner Strasse 126, D - 50968 CologneTranslation from French: Matthew Clarke and Ian West in association with First Edition Translations Ltd.Editing: Kay Hyman in association with First Edition Translations Ltd.Typesetting: The Write Idea in association with First Edition Translations Ltd.Project Management: Beatrice Hunt for First Edition Translations Ltd., Cambridge, EnglandProject Coordination: Nadja Bremse-KoobProduction: Ursula SchumerPrinted in Italy by STIGE - TurinISBN 3-8290-1736-710 9 8 7 6 5 4 3 2 1

PLANTS 188Origin and variety of plants 190Algae problems 193Caring for plants 196Catalog of plants 201TECHNIQUES 216Assembling a tank 218Equipment and accessories 226A balanced aquarium 253Choosing the bed 260Decor and background 264Final preparations 272CUSTOMIZING YOUR TANK 278USEFUL INFORMATION 282INDEX 283

INTRODUCTIONThere was a time when the keepingand study of exotic fish was the preserveof serious researchers closetedin their laboratories; today, it is anestablished and popular hobby. Dealershipsand specialized sales areas in largestores are springing up everywhere, parallelingan explosion in the number of publicaquariums and books or magazinesdevoted to the subject. More and morepeople of all ages are falling under thespell, enjoying permanent access to a partof the natural world that was formerlybeyond their reach. There are almost asmany kinds of hobbyists as there are typesof fish: the semiprofessional, the "small"and the "modest" collector, the specialist.There are the fanatics, who spend everyminute of their time and energy on theiraquariums, while for others fishkeeping isjust a passing fad. Enthusiasts include theyoung - and the not so young; those withscientific knowledge or mere novices;those actively working and the retired.Such an immensely varied following guaranteesthat the world of the aquarist is fullof interest and color.of our living rooms, a small window onto thewide world outside. An aquarium also providesa glimpse into a different universe - butthis time inhabited by real, live creatures.A lot of thought and work goes into a topclassaquarium. We select the best site, wewant fish and decor which satisfy oursense of beauty. Before long, our newpurchase has relegated to the backgroundour photos, pictures and even the TV.The last ten or so years have seen theaquarium come into its own in institutionsand public buildings. In educational establishmentsit represents an important teachingaid, enabling students to observecreatures in conditions resembling theirnatural habitats. The medical professionhas likewise realized its benefits. The fishgliding through their silent, predominantlygreen world in a kind of underwater balletare the perfect sedative for nervouspatients; it is by no means unusual tocome across tanks in the waiting-rooms ofdoctors and dentists, in physiotherapyrooms, hospitals, and indeed in psychiatricclinics. More recently, aquariums havebeen introduced into prisons.In a dentist'ssurgery, a tank ofAmazonian fishfaces the patient'schair. •A WINDOW ONTO ANOTHERWORLDWe have all become familiar with how ourtelevision screens offer us, from the comfortFISHKEEPING, SCIENCE, ANDAQUACULTUREKeeping fish contributes to the developmentof scientific research into aquatic environments,and is relevant to the study of animaland plant biology, ecology, reproduction,feeding, and behavior. Researchers usesome species to test the toxicity of pollutantsor suspected pollutants.Aquaculture or fish farming - the productionof living creatures with the principalaim of selling them as food - has featuresin common with fishkeeping. In bothcases, it is a matter of maintaining fish incaptivity and encouraging them to reproduce,always under the best possible conditions.The use of aquariums has allowedus to improve our knowledge of, for8

example, the breeding of marine larvaedestined eventually for human consumption.It can also aid the preservation ofspecies threatened with extinction for variousreasons; we can study their behaviorand reproductive methods with the aim ofrearing young which can be released intotheir natural habitats.On the other hand, aquarists are regularlyaccused of being party to the destructionof certain environments.The fact is that though the vast majority offreshwater fish kept in aquariums are theresult of captive breeding, the same is nottrue of marine fish, which are caughtmainly in their natural habitats. The numberstaken are out of all proportion to theneeds of aquarists owing to unsatisfactoryconditions of capture and transport. Forevery marine fish which arrives alive in anaquarium, how many have died as theywere being caught - often in a highlyquestionable manner - or during shipmentor in the course of acclimatization?In this sense, the accusation is justified.The only solution is to impose strictercontrols and improve techniques so thatthe number of fish caught to supplyaquarists remains within a safe limit.A SYSTEM IN EQUIPOISEThe days of goldfish swimming in endlesscircles in a glass bowl are long past.Today, an aquarium is something muchmore sophisticated: we are able to reconstructNature in microcosm, whichrequires the maintenance of a constantequilibrium. Nature, if not disturbed bysome cataclysmic imbalance, obeys afinite set of laws. As aquarists, we need tounderstand these laws and reproducethem on a smaller scale, where the densityof animals and plants is considerablyhigher. Everything that takes place withinthis mini-universe is under our control -up to a point. The final, inviolable law isthat conditions in the aquarium mustalways approach those found in Nature. Ifnot, the ecosystem will break down,spelling disaster.THE AQUARIUM: ANALTERNATIVE APPROACH TOECOLOGYA closed system like this lends itself particularlyto the understanding of ecology,providing an excellent introduction to abranch of science which emerged in the19th century but has acquired a high profileonly in the last twenty or so years. Itis not concerned simply with Man and hisworld, as many believe, but covers all themechanisms regulating relationshipsbetween living creatures and their environments,so that all can live in harmony.• Salmonidae inLe BugueAquarium. Publicaquariums havean important roleto play, offeringunrestricted accessto the beauty ofthis miniatureworld.9

FRESH WATERten: the bacteria. The latter transform theorganic matter emitted from living beings(excreta and various other residues), andthese chemical reactions similarly requireoxygen.The oxygen in water comes from the dissolutionof the oxygen in the air, a processenhanced by movements in the water producedby wind, currents, or downwardflow. The more water is stirred, the moreit is oxygenated. Plants also provide oxygen,which they produce through photosynthesis,although this process occursonly by day. The maximum amount ofoxygen that water can contain is determinedby its temperature: the higher thisis, the less oxygen the water can contain(at 25°C there is 18% less oxygen than at15°C).Oxygen is measured in mg/liter, and itscontrol is quite a complicated matter. Themost turbulent, and therefore the mostoxygenated, water contains 8-10 mg/liter,while the most deficient water sometimeshas less than 2 mg/liter.The oxygen content in an aquarium is usuallyat its maximum, providing the recommendationsfor stirring the water arefollowed. The rare problems which dooccur are the result of negligence asregards the overall balance of the aquarium(overpopulation of fish, small numberof plants), or non-functioning of equipmentdue to forgetfulness, breakdown, ora power cut.Carbon dioxide derives from the respirationof fish, plants, and bacteria. Stirringthe water enhances its oxygenation,thereby reducing the levels of carbondioxide in the water, and passing it intothe atmosphere. Carbon dioxide is quiterare in an aquarium, and this can, to someextent, prove prejudicial to plants, as theyabsorb it by day through photosynthesis toextract the carbon they need to grow.It is therefore vital to establish a permanentequilibrium between oxygen, carbondioxide, plants, and fish, although this balancechanges at night, when plants stopproducing oxygen.Carbon dioxide is also one of the main factorsaffecting the pH.PH VALUESThe pH measures the acidity or alkalinityof water, with the value 7 representingneutrality. Below this level the water isacid, and above it the water is alkaline (orbasic). Categorizing water as acid doesnot mean that it contains dangerous acids.In forest streams and rivers the wateraccumulates with acid organic fluid(humic acid) derived from the decompositionof plants (humus), producing anamber yellow color.Generally speaking, aquatic life can existonly between pH 5 and 9. These extremevalues are rarely found in an aquarium,where the pH ranges from 6 to 8 accordingto the type of water, and usually liesbetween 6.5 and 7.5. In aquariums, theterm acid water corresponds to a pHbetween 6 and 6.8, while alkaline waterMaximum oxygencontent of wateras a function oftemperature •T°C1516171819202122232425262728mg/lrter10.19.99.79.59.39.18.98.78.68.48.38.17.97.813

WATER, A HAVEN FOR LIFEpH is measured byusing a color test:water from theaquariumcontaining a fewdrops of the test iscompared to acolor scale thatprovides areasonably precisedetermination ofthe pH value. T14refers to one between 7.2 and 8, and a pHbetween 6.8 and 7.2 is considered neutral.Variations in pH are mainly the result ofbiological activity: the carbon dioxide producedby living beings acidifies the waterat night and the pH goes down slightly.Once the carbon dioxide has beenabsorbed by the plants during the day thepH goes up again.Although slight variations are thereforenormal, more extreme changes can be awarning signal. The pH is a good indicatorof an aquarium's equilibrium, and itshould therefore be measured regularly. Acolored marker dipped into a sample ofwater is used to compare the colorobtained with the scale provided. Electronicmeters are also now available fortesting pH values.Adjusting the pHThe pH of domestic water may not alwaysbe particularly suited to the fish you havechosen. Furthermore, when an aquariumis in use the pH can rise and fall, slowlybut very regularly. There are some aquariumproducts on the market that enableadjustments to be made to the pH, butthere are other ways of modifying it.• If the pH is too high- the water can be diluted with anothermore acid water;- the stirring of the water can be reduced.Carbon dioxide is eliminated less quicklyand remains in the water to acidify it. Becareful, because decreasing the stirringalso lowers the oxygenation;- the water from the aquarium can be filteredover peat, which will release certainacids. The amount of peat needed to

FRESH WATERmaintain a specific pH value must befound through trial and error, with regularmeasurements of the pH.• If the pH is too low- the water can be diluted with anothermore alkaline, and generally harder water(see Hardness, below);- the agitation of the water can be increased,enhancing the elimination of the carbondioxide dissolved in the water and thereforelifting the pH;- the water can be filtered over calcareousmaterial, rock, or oyster shells broken intolittle pieces. In this case, the hardness alsoincreases (see below).HARDNESSThe hardness of water refers to the combinationof substances based on calcium(Ca) and magnesium (Mg) that are containedin it. The main substances, knownas salts, are carbonates, bicarbonates andsulfates.Water with zero hardness does not containany of these salts; this is the case with distilledwater.The water in some areas can be particularlyhard, mainly due to the presence oflimestone (or calcium carbonate).The hardness of water really depends onthe land through which it has passed: themore calcium and magnesium the rockscontain, the harder the water. The effectsof this can be seen in domestic use: awashing machine, for example, willrequire more detergent. Above certainlimits of hardness (see the table on page17), water is unfit for human consumptionor any other use. Water with a low degreeof hardness, i.e. containing few calciumand magnesium salts, is considered soft.Water with a high degree of hardness isclassified as hard.FOOD CHAINSIn natureLife in water, as on land, is not possible without light. Vegetation(microscopic plankton or plants) absorbs it with carbon dioxide(CO 2 ) and uses the mineral salts, which act as nutrients. Thisvegetation serves as food for herbivorous or omnivorous fish, whichin their turn provide nutrition for carnivorous fish. From this point,the next link in the chain can be aquatic (dolphin, shark), terrestrial(man), or aerial (bird). When aquatic organisms die, they fall to thebed. Their bodies are degraded by the action of bacteria, thematerial is recycled into mineral salts, and so the chain comes fullcircle. (While they are alive, it is their excreta that are recycled.)There are kits on the market that offereven the novice aquarist the panoply oftests required to control the majority ofthe main parameters for water.15

WATER, A HAVEN FOR LIFEPEATPeat derives from the decomposition of vegetation in an acidenvironment lacking in oxygen. This process, which lasts severalcenturies, gives rise to a peat bog from which compact, fibrous peatcan be extracted.It endows water with both a yellow amber color and acidity, whichgives it slightly antiseptic properties. This means that some diseasesare less common in acid water. The use of horticultural peat, whichoften has been enriched with various products, must be avoided infavor of the peat for aquarium use that is commercially available.Boil it for around 15 minutes before use.Hemigrammus erythrozonus.In the Amazon region of South America, the color of the waterranges from amber yellow to brown, due to the leaves andbranches floating in it. In an aquarium, peat can be used in thefiltering equipment to reproduce the characteristics of this type ofwater (low hardness, pH under 7, coloring).Pterophyllum scalare. TThe hardness of water is expressed inGerman degrees (°GH or °DH), not to beconfused with Celsius degrees (°C) fortemperature: 1°GH is equivalent to 17.9mg Ca/liter, or 17.9 parts per million(ppm). The term most often used to classifyhardness is general hardness (GH),although total hardness (TH) can also beused.There are three main categories of waterin fishkeeping:- soft water, which is generally acid, at3°GH or 50 ppm;- medium water, which is neutral orslightly alkaline, at 6°GH or 100 ppm;- hard water, which is highly alkaline, at12°GH or 200 ppm.We will go on to discover that some fishfamilies can adapt only to certain types ofwater.Measuring GHA colored indicator is used: the number ofdrops needed to obtain a change in colorindicates the degree of hardness.It should be noted that the degrees ofhardness used in analysis kits may varyaccording to the country in which it wasmanufactured; in some cases French degreesare used. These can be converted as follows:1°Fr=0.56°GH• How can the degree used by a manufacturerin a product be identified?To confuse matters further, you may alsocome across °Clark in older books on fishkeeping.The old-fashioned Clark systemfor hardness was somewhat laborious,being based on measurement of the foamcreated by a soap solution, and has nowbecome obsolete. If you have any doubtsabout the units used by the manufacturer ofan analysis kit, just measure a GH youalready know, such as that of bottled water(see page 23).The relationship between GH and CHWe have already seen that significantchanges in the pH are prejudicial to aquaticlife,especially if they occur too abruptly. To16

WATER, A HAVEN FOR LIFEA Capetatetrazona (herethe golden variety)prefers soft tomedium-hardwater, especiallyfor reproduction.18compensate for this, nature has provided ascreening device, the CH (carbonate hardness,i.e. the hardness due to calcium andmagnesium carbonates and bicarbonates).The higher this is, the less the risk of anymajor variations in the pH. and vice versa.This phenomenon, known as buffering, cantherefore only occur in acid fresh water.There is a relationship between the CH andthe general hardness: the closer the CHvalue comes to the GH value, the more balancedthe water. If the CH is less than 75%of the GH, you are likely to encounter aproblem, and it is therefore not advisable touse water with these characteristics in anaquarium.Modifying the hardness of waterSometimes the water available presents ahardness value inappropriate for itsintended use in an aquarium. In mostcases, the water will be a little too hard,and so the GH must be brought down foruse in a mixed aquarium or a rearing tank.In other, less common cases, the water canbe slightly too soft, and so the GH needs tobe raised.• Reducing the GHWater with a low hardness value can bemixed with water that is too hard. Thereare several alternative sources of water(see pages 21-23):- rain water;- spring and well water;- defrosting water from a refrigerator;- water from melted snow;- distilled water, available in bottles;- some brands of mineral water;- natural flowing fresh water.The volume of water that can be obtained,and its price, obviously depend on whichof these sources is used. Filling a tankwith a capacity of several hundred literswith water of a precise hardness cansometimes be a laborious process. A finalpiece of advice: avoid using water from adomestic softener, as the calcium salts arereplaced by other salts. Osmosed water(see page 17) is an attractive option, butthe equipment represents a substantialinvestment.• Increasing the GHThe water in question can be diluted withharder natural water, generally easier tofind than soft water, or put some calcareousrocks in the aquarium, regularly monitoringthe GH, or filter the water overoyster shells crushed into tiny pieces.Any modification in the hardness of wateris matched by a modification in the pH:increasing the hardness of the water alsoincreases its pH, and vice versa.Obtaining water with a precise hardnessLet us suppose we have two types ofwater, one hard and one soft, with whichto "manufacture" an intermediate water:- water A, with a GH of 9°GH;- water B, with a GH of 3°GH;- target water, with a GH of 5°GH.Calculations:GH water A - GH target water = 9-5 = 4.GH target water - GH water B = 5 - 3 = 2.The combination of 4 liters of water B and2 liters of water A results in 6 liters at5°GH. Filling a 180 liter tank will require180 (6 x 30 times this mixture, i.e. 60 litersof water A and 120 liters of water B).Another example with the same water:filling the same tank with water at 7°GHwill require 120 liters of water A and 60liters of water B.

TURBIDITYThe turbidity of water refers to the presenceof suspended matter - either livingorganisms forming plankton (rare in anaquarium) or inert matter, such as animalor vegetable remains or particles of sediment,particularly mud.The size of this suspended matter rangesfrom a few thousandths of a millimeter toseveral millimeters. In calm, unstirredwater it forms sediment at a speed in proportionto its weight. In running or turbulentwater, some of the matter remainspermanently suspended, giving rise tomore pronounced turbidity.In aquariums, where the water is alwaysin motion, systems of varying degrees ofsophistication (see Filtration, page 237)allow fishkeepers keep their water clear.The effects of this are entirely positive:- the visual appearance is improved;- the light required by the plants penetratesthe water and reaches them moreeasily;- there is less risk of disease, particularlyin the fishes' branchiae;- there is little sedimentation on the baseof the tank, reducing both the possibilityof any warping due to excessive weightand the decomposition of organic matter.NITROGENOUS PRODUCTSAND THE NITROGEN CYCLENitrogen (N) is one of the components ofcertain substances, largely derived fromthe excretion of fish, that are dissolved inwater. These substances, of varying structuralcomplexity, are quickly convertedinto ammonia (NH3 or NH4+), which ishighly toxic for animals. At this point oxygenand bacteria intervene to convert theammonia into nitrites (NO 2 -), which arealso very toxic. Other bacteria, still accompaniedby oxygen, transform them in theirturn into nitrates (NO3-), slightly toxic forfish but which can be used by plants asnutrients. These transformations, taken asa whole, are referred to as the nitrogencycle. In nature, land-based elements canalso participate (see diagram). As plantsare at the base of the food chain, they alsotake part in the nitrogen cycle.In an aquarium, the situation is different.Some fish partly feed on plants, but mostof them are fed by the aquarist; sometimesthere is a surplus of foodstuffs and thenitrogen cycle is altered as a result. It isvery important to respect the equilibriumof this cycle. That is why you should notkeep too many fish and you should notoverfeed them. It is also a good idea toprovide the aquarium with a sufficientamount of vegetation, and to enhance thedevelopment of bacteria, while ensuringthat the water is well aerated. Partial andregular water changes make it possible toeliminate surplus foodstuffs, various typesof organic matter, and any nitrates thathave not been used by the plants. A biologicalfilter enhances the development ofthe nitrogen cycle.FRESH WATER19

WATER, A HAVEN FOR LIFENitrates, the finalproducts in thenitrogen cycle, areused as mineralsalts by the plants.•Bacteria in the nitrogen cycleRarely found in open water (around 1% ofthe total count), bacteria colonize essentiallythe floor and the decor. They feedon nitrogenous compounds in the water,extracting the oxygen from them.When anaquarium is brought into use, bacterialcolonization of the environment is a slowprocess, and so it is advisable not to introducethe selected fish until 2 or 3 weekshave elapsed.The toxicity of nitrogenous compoundsThe concentration of nitrogenous compoundsin an aquarium is higher than in abalanced natural setting, and there aresome limits which must not be exceeded(see table above).Ammonia is found in two different formsin water, and the sum of the two must notbe more than 0.4 mg/liter. Dissolved NH 3ammonia gas is the most dangerous,although it only appears above a pH of 7and rarely exceeds 10% of the total ammo-20

FRESH WATERLEVEL OF NITRITES (NO 2 -)No nitrogenous substance should pass the thresholdlimit in a well-balanced aquarium. As ammonia andnitrates are more difficult to assess, it is the nitrites that must beanalyzed regularly. There is a colored marker commerciallyavailable, which gives a stronger color according to the amount ofnitrites present. If the latter are too abundant:- either there is a general imbalance (too many fish, too muchfood in the water) which entails a high production of ammoniaand, therefore, nitrites;- or there is a problem connectedwith the transformation ofnitrites into nitrates,often a lack of theoxygen requiredby bacteria.The level of nitrites,like the pH leveldiscussed above, is agood indicator of theequilibrium of anaquarium, and it istherefore important tomeasure it regularly. The darker the pink color, themore nitrites there are in thetested sample.nia. The more common ionized NH 4 + formis slightly less dangerous.OTHER DISSOLVED SOLIDSA great many other substances are to befound dissolved in water. Their content isgenerally low and does not pose any problems,and some of them, such as micronutrients,are even very beneficial. This termcovers a variety of elements including vitaminsand metals, which in tiny quantitiesare indispensable to life.Iron, for example, plays a role in the compositionof hemoglobin, the red blood cellswhich transport the oxygen taken in by thebranchiae. It also participates in the photosynthesisof plants, which have a tendencyto turn yellow if there is an iron deficiency.Manganese is equally important, as it is oneof the components of chlorophyll, thegreen pigment in plants that allows them toabsorb light and develop.There are, of course, other metals that arealso naturally present in water, but theirconcentration hardly ever exceeds a fewthousandths of a mg/liter, and some, suchas copper, become toxicif it goes beyond thislimit.Origin and quality offresh water used inaquariumsThe simplest and cheapestmeans of obtainingwater is turning on afaucet, but there areother possibilities,especially when itcomes to obtainingnatural water.• Domestic waterAs long as water isdrinkable, there isno reason why it isnot suitable for fish.In some regions thewater is sometimes toohard (general hardnessabove 11°GH), and sothe option of mixing itwith softer water mustbe considered.Domestic water must never be introducedin large quantities into an aquarium whichalready contains fish. It is also advisableto let it settle for 24 hours to eliminate anyexcess of gas (caused by the pressure).When filling a tank before putting it intooperation, this step is not compulsory, asit will not be housing fish immediately.• Natural waterNatural water close to home usuallyshares many of the characteristics ofdomestic water, as it makes up a large partof the public water supply.However, it should be possible to findwater with different characteristics not toofar away.• Spring waterThis is the most desirable water, as it isthe purest, with no suspended material,little or no organic matter and a high bacteriologicalquality.• Well waterThis is of a similarly good quality,although it sometimes contains an excessof gas. It can occasionally be slightly ferruginous(containing iron), which favorsthe growth of plants.21

OPTIMUM CHARACTERISTICS OF FRESH WATER SUITABLE FOR AQUARIUMSParametersColorTurbiditySmellTemperaturepHOxygenHardnessAmmoniaNitritesNitratesOptimum characteristicsColorlessNoneNoneUnder 25°C6-9The maximumUnder 16.8°GHUnder 0.4 mg/literUnder 0.1 mg/literUnder 50 mg/literObservationsYellow-colored water contains organic matter.The water must be limpid and crystal-clear.Sometimes water containing organic matter hasa characteristic smell of humus.It is advisable to collect water with a temperaturebetween 5 and 15°C.It should preferably be between 6.5 and 7.5.This is the case with springs and streams.Stagnant and still water is not suitable.Beyond 11.2°GH, it must be mixed with freshwater (except in rare cases, for certain fish).This value is rarely attained in balanced water.This is the drinking water threshold.This is the threshold for drinking water, often exceededin farming areas.Type of waterWATER USABLE IN AQUARIUMSCharacteristicsUse in aquariumsDomestic waterDefrosting waterfrom refrigeratorDistilled/demineralized waterBottled waterVariable according to region,often a little hard and alkalinein major urban areas.Zero or very low hardness,pH close to neutral.Neutral, fresh.Variable. Volvic is one of the softest.Untreated, or first mixed.Total or partial filling of an aquarium.Dilution of hard and alkaline water.Dilution of hard and alkaline water.Dilution of hard and alkaline water.There are several brands of mineralwater soft enough for this purpose.Natural waterRainwaterWater from melted snowSpring or stream waterWell waterPonds, down-river waterFresh and acid (or neutral),often containing pollutants.Barely mineralized and closeto neutrality.Variable according to region,generally with little turbidity.Variable according to landbored, with little turbidity.Variable, but often turbid.Dilution of hard water.Its use to be avoided in anurban or industrialized area.Dilution of hard water. Only tobe collected if it is very clean.Total or partial filling of an aquarium,mixture with other water.Total or partial filling of an aquarium,mixture with other water.Not to be used, microbiological risk.

FRESH WATERMovement inwater, whether ina natural setting orin an aquarium, isthe best means ofenhancing itsoxygenization.• RainwaterRainwater is soft and acid, so is useful fordiluting water that is too hard. It shouldbe collected in plastic containers; if theseare put under a gutter, take care not tocollect the first water, as this will havecleaned the roof. In urban and industrialareas, rainwater is liable to contain pollutants,and it is therefore not advisable touse it.• Stagnant water (ponds)and still water (downriver)Such water can posea microbiologicalrisk, and it is notadvisable to use it.• Demineralized anddistilled waterTheir pH is neutral orvery slightly acid,with little or no hardness.Their high pricemeans that they are only used for mixingwith hard water, or for filling a small rearingaquarium. Do not forget that softenedwater cannot be used.• Bottled waterThis is often referred to as mineral water -erroneously so, as some brands containhardly any minerals and are quite soft.These are certainly not used to fill up hugetanks, bottle by bottle, as this would betoo expensive and time-consuming, andtherefore serve a similar function to that ofdistilled water.•4 Somemineral watercan be usedin aquariums.23

SEA WATERThe main difference between fresh water and sea water is that the latter contains a greatmany salts which give it certain specific characteristics, and these must be understood byany aquarist who wishes to keep marine fish.A Very highquality sea wateris required inmarine aquariums,especially if theycontaininvertebrates,particularlyanemones andcorals.24TEMPERATUREThe temperature of tropical sea watervaries little over the course of a day, oreven a year. Furthermore, marine fish aregenerally more sensitive to abruptchanges than freshwater fish. The temperaturein an aquarium must, therefore, befairly stable, remaining at around 25-26°C.SALINITYThe most important salt found in seawater is sodium chloride (NaCl), widelyused for domestic and culinary purposes,but there are plenty more.The salinity of water, i.e. the quantity ofsalts in the water, is expressed in 0 / 00 or ing/liter. The mean salinity of the Earth'soceans is around 35 0 / 00 , or approximately35 g salts/liter.Whatever its salinity, sea water boasts oneremarkable property: the proportion ofeach element is constant.Desalinated water does not therefore containless of one or more salts, but thecombination of salts is present in a lowerconcentration.The salinity of sea water varies accordingto longitude. It is at its highest in openseas in the tropics, it is lower near coastsand after heavy rain, and it is at its lowestnear the poles (due to the influence ofmelting snow).DENSITYIn marine aquariums, it is not the salinityof water which is measured, but the density(often expressed as specific gravity,S.G.), which can be calculated accordingto the following formula:

SEA WATERMEASURING DENSITYThere are no units of measurements.The saltier the water, the higher its density.The density also varies according to temperature(it goes down as the temperaturegoes up). The table overleaf showsthe relationship between salinity anddensity with respect to temperature,which is relatively constant (25-26°C)in aquariums. The density, expressedas specific gravity, a value which iseasy to use, is all that is required tocalculate salinity: it must rangebetween 1.022 and 1.024.Density is measured with a hydrometer, whosebuoyancy increases as the water gets saltier. In theaquarium trade, most hydrometers also include a thermometer.The specific gravity at water level must be read with care; in fact,it is preferable to use the hydrometer outside the aquarium, as themovement of the water makes it difficult to read. In this case,decant the water into a test tube or a transparent container (a PVCbottle, for example) and float the hydrometer in it. When it stopsmoving, read the value corresponding to the level of the water(1.023 in the diagram below, and not 1.022). To check whetheryour hydrometer is working properly, just measure the density ofa distilled or very soft water: it must equal 1.000.THE CHUnlike the general hardness (GH)which is used to describe freshThe hydrometer, an indispensabletool in marine aquariums. •

WATER, A HAVEN FOR LIFEwater, carbonate hardness (CH) is used insea water, where it serves to measure thequantity of calcium and magnesium carbonatesand bicarbonates present.This is crucial for maintaining the pH, andfor growing corals, which have skeletonsmade of calcium carbonate.PH VALUESAs sea water is salty, its pH is thereforehigher than that of fresh water. Pure seawater in the middle of the ocean has a pHof 8.3- Near the coasts, this drops to about8 or a little less, as its dilution with freshwater lowers the salt content. The pH ofsea water in an aquarium must varybetween 8 and 8.5; beyond these values,animals will experience certain physiologicalproblems.Variations in pH in a marine aquariumSea water contains a great deal of calcium carbonateand bicarbonate, and there are onlyslight variations in pH in a natural setting.It is a different matter in an aquarium, arestricted habitat operating as a closedcycle. The pH must not fall below 8, but aslow and regular decrease in this parametermay be seen. Why? The water in anaquarium sometimes contains too muchcarbon dioxide, which has a tendency tolower the pH.What can you do? The first step is to measurethe CH:- if it is under 7.2°CH, add calcium orreplace some of the water. This situation is,however, fairly rare in an aquarium withoutcorals, solely occupied by fish;- if it is over 7.2°CH, there is an excess ofcarbon dioxide. Stirring of the water musttherefore be increased by using diffusers oran electric pump.THE NITROGEN CYCLEThis occurs in the same way in sea waterand fresh water. In a marine aquarium thevegetation is often less abundant than infresh water, and so the nitrates, the endproducts of the nitrogen cycle, will have atendency to accumulate.At high doses these pose little danger tofish but are toxic for invertebrates, especiallycorals. It is therefore important toeliminate them by partial, but regular,water changes.26

SEA WATERFINDING OUT THE CHARACTERISTICSOF NATURAL WATERThe European Union has set compulsory standards for drinking and environmental quality, but the strict legislation inthe UK goes well beyond these. In England and Wales, for example, domestic water is monitored by the Drinking WaterInspectorate, which regularly checks up on the practices of the water companies and investigates any possibleinfringement of the law.The Environment Agency, on the other hand, is responsible for the quality of water in rivers, estuaries, and coastal areas.It issues licenses to discharge waste into these waters and takes chemical and biological samples to monitor the effecton the environment. The results of these controls are available to the public.Once a marine tank has been put intooperation, the nitrogen cycle is slower totake effect than in a freshwater tank:around 3-4 weeks (although this is a generalization,as every aquarium is unique).Fish or other animals must not thereforebe put into the water during this period,although the length of time can bereduced by various means (see Assemblingyour Tank, page 218), based on theprinciple of introducing bacteria. In anyevent, measuring the nitrite levels is anexcellent indicator of the progress of thenitrogen cycle.Once the water has been put into the tank,this parameter must be measured regularly;when the quantity of nitrites goesdown close to zero, the nitrates appearand you only need to wait a few daysbefore inserting the fish. Nevertheless,measuring the nitrites at regular intervals isstill highly recommended, as long as theaquarium is in use.OTHER DISSOLVEDSUBSTANCESSea water contains more than 60 elements,some of them in microscopic amounts: forexample, there is 1 g/m 3 of gold in seawater.All the solids dissolved in sea water servea purpose, and that is why the salts thatare used to reconstitute water must be ofexcellent quality.Some substances can accumulate in seawater and in high concentrations give riseto concern. This is especially true in thecase of organic matter, but it is possible toeliminate them by partially changing thewater or using certain devices, such as anaerator (page 250).As soon as the water is put in the tank, the ammonia contentrises until, as shown in the graph, it reaches its maximumlevel after 8 to 10 days.Simultaneously, the bacteria wich transform this ammoniaare developing and nitrites are formed, reaching their peakaround the 15th day. Other forms of bacteria also develop,converting, in turn, these nitrites into nitrates. While thenitrites disappear between the 20th and 25th days, thenitrates must be eliminated by partial water change.The establishement of this cycle requires at least 3-4 weeks.During this period the ammonia and nitrites reach levelsthat are sometimes ten times that of toxic doses (identicalto those of fresh water, see page 20).27

WATER, A HAVEN FOR LIFEmarshes. Furthermore, good sea watercannot be reconstituted using poor qualityfresh water.The collection ofwater from acoastal area is tobe avoided,especially whenthe locality is usedfor dumpingurban or industrialwaste. •28TURBIDITYClarity is more important in sea water thanin fresh water. Tropical environments inparticular contain very few dissolvedsolids and they are the most transparentwaters on the planet. A marine aquariummust therefore be filtered more efficientlyand to a greater extent than a freshwatertank (see Filtration, page 237).THE ORIGIN OF SALT WATERIN MARINE AQUARIUMSThe first idea which springs to mind isthat of collecting natural sea water, butthis is difficult for somebody who lives along way from a coast or requires largequantities. Moreover, although sea waterdoes present advantages,it also has itsinconveniences.While some aquaristsfilter it beforeusing it to totally orpartially fill up theirtanks, the majorityuse reconstitutedsea water. In theory,the recipe is a simpleone: dissolve thesalts in the water. Inpractice, however,not just any water orany salts can beused, and it is out ofthe question to usetable salt or thatderived from saltWhere and when to collect natural seawater?The ideal solution would be to go to theopen sea, where the water is likely to beless polluted and to have more constantcharacteristics. Near the coasts, the followingmust be avoided: urbanized orindustrialized areas and ports, which aresusceptible to pollution; anywhere nearriver mouths, estuaries, or bays, where thewater is desalted; and areas of stagnantsea water (pools at low tide) and saltmarshes.Coasts with sand dunes are suitable inprinciple, but the water is often ladenwith suspended sediment. Rocky coastsare preferable regions from where watercan be collected.The best periods for collection are autumnand winter, because plankton develop inspring and tourism increases the risk ofpollution in summer. Calm weather ispreferable, in order to avoid suspendedmaterial, although a heavy swell reoxygenatesthe water. In this case, the watercan be collected 1-3 days later, the time inwhich the suspended material turns intosediment. However, the water must be filteredin all cases, first roughly and thenmore finely.

SEA WATERSalt collected insalt marshes is notsuitable forreconstituting seawater intended foran aquarium.ADVANTAGES AND DISADVANTAGES OF NATURAL SEA WATER AND RECONSTITUTED SEA WATERAdvantagesNatural sea water• It is economical and contains all theelements necessary for life, as well as "good"bacteria.Reconstituted sea water• It does not contain suspended sediment,organic matter, pathogenic bacteria, orpollutants.• It is manufactured with the desired salinityand can be stored in a concentrated form(3-4 times the desired salinity).Disadvantages• It must be collected (traveling andcontainers).• According to where it is collected, it maycontain suspended sediment, organic matter,pollutants, and pathogenic bacteria.• The salinity varies according to when andwhere it is collected.• It may contain plankton, with the risk thatthis may develop in the aquarium - hardlydesirable.• More expensive than natural sea water, itsometimes lacks certain micronutrients.• It does not contain "good" bacteria.• It cannot house animals for several weeks,the time taken for the nitrogen cycle to beestablished.Generally speaking, the advantages of one correspond to the disadvantages of the other, which is why some aquaristsmix both types of water.29

WATER, A HAVEN FOR LIFEThe reconstitution of artificial sea waterThe quality of the fresh water used isimportant: it must be as pure as possible. Itis best to use water with a hardness of lessthan 8.4, although reconstitution is stillpossible with higher levels, providing theCH is equal to at least 75-80% of the generalhardness value. Take care to avoidwater containing nitrates (often found infarming areas), to which invertebrates arevery sensitive, or metals, toxic for someanimals where present above certain limits.Making sea water in anaquarium, beforeputting it intooperationFill the aquarium withfresh water and aerate itfor 24 hours. Calculateand weigh the quantity ofsalts to be dissolved, thenintroduce them into theaquarium. Then just aerate for another24-48 hours and check the density, adjustingit as required.ARTIFICIAL SALTSSeveral companies have special aquarium saltson the market, and it is even possible to findconcentrated sea water. Some salts areintended for marine tanks for fishes, others foraquariums with invertebrates. Their quality issatisfactory, although there are likely to beimprovements in the future, and, as they areenriched with calcium, micronutrients, andvitamins, they are obviously relativelyexpensive. There havebeen no adversereports to date aboutthe use of thesesalts in aquariums:in those areaswhere accidentsdo occur, theyare usuallydue to miscalculationson the part of the aquarist.• Artificial sea water can be reconstitutedwith the help of special salts available inaquarium stores.30

Making sea waterfor storage andback-upThe method is thesame, except thatplastic food containersare generallyused. The quantityof salt can be multipliedby three orfour to manufactureconcentrated waterthat will thereforeoccupy less storagespace.Adjusting thedensity• The density is too highPart of the water is siphoned off - this can be storedfor later use - and the softest water available isadded, taking care to measure the density. When thewater level of a marine aquarium goes downbecause of evaporation, it is not the sea water whichis evaporating but the fresh water, and it is thereforethe latter which must be added to make up the level.SEA WATERThe addition of sea water would entailan increase in density.• The density is too lowIn this case, salts must be added. Thesemust be dissolved beforehand in a containerwhich is then gradually emptiedinto the aquarium, with constantchecks on the density. Both theseoperations must be performed withcare if the aquarium already containsfish, in order to avoid causing anyexcessively abrupt changes that couldbe detrimental to the fish.Artificial sea water, reconstituted with commerciallyproduced salts, creates an environment that isperfectly suited to fish.31

DIFFERENT TYPES OF AQUARIUMAn aquarium is not just a motley collection of plants and fish. Some aquarists aim toreconstruct the biotope of a specific geographical region (Central America, the Amazon,Asia, Africa), while others concentrate on a single group of fish (for example, livebearers,Cichlids, or marine fish). Whatever the option, an aquarium must be attractive and wellbalancedfor its occupants to thrive, and this entails some understanding of the varioushabitats, as well as their inhabitants.• Communitytank.An aquarium is a collection of elements -fish, plants, soil, rocks, water - which arecompatible with each other. However,there are several types of aquarium, allsharing the same general principles andtechniques but differing with respect tothe environment created. Aquariums aredivided into two main groups:- temperate aquariums, often mistakenlycalled cold water aquariums, where thewater temperature can range from 5 to25°C;- tropical aquariums, with either fresh orsea water. These cover the areas lyingroughly between the tropic of Cancer, tothe north of the equator, and the tropic ofCapricorn, to the south, where the watertemperature varies by only a few degreesthroughout the whole year.TEMPERATE WATERAQUARIUMSThese are not heated, and ideally thewater temperature should vary to thesame extent that it does in nature (from 5to 25°C, approximately). This is difficult,as room temperature barely falls below15°C and is often over 18°C. Apart fromthis difference, the underlying principle isthe same as in any aquarium: to recreatean environment. This demands just as32

DIFFERENT TYPES OF AQUARIUMmuch time and care as with tropicalaquariums. It must be stressed that we arenot talking about goldfish bowls!Temperate aquariums house robustspecies, among them the fish found in ourrivers and ponds, which fall beyond thescope of this book. On the other hand, wewill cover goldfish (Carassius auratus), alltoo often neglected in favor of tropicalspecies, but which, in their innumerablevariety, give great pleasure to many hobbyists.Still within this temperature range, mentionmust be made of garden ponds,where goldfish and koi carps (coloredvarieties of the common carp) can be keptand bred. If they are well designed, suchponds can recreate a natural biotope, withaquatic and terrestrial plants, invertebrates,and amphibians. Sometimes theycan also play host to tropical fish for abrief summer stay, if the temperature permits.After all, fish can take vacations too,especially if they coincide with yours! It isa practical solution when there is nobodyto look after an aquarium during a longabsence, and when you come back youmay be amazed by the weight the fishhave put on, or by some unexpected newarrivals.On the other hand, do not be too surprisedif some fish have disappeared,unable to tolerate the change of setting -or the predatory instincts of the local cat.TROPICAL AQUARIUMSThe community aquariumHere fish and plants not native to thesame region are found side by side, creatingan environment that does not exist innature. The results may be charming andingenious, but this type of aquarium isoften disparaged by purists.A community aquarium is often a popularchoice with beginners creating - or"mounting", in aquarists' jargon - their firsttank, although this is not a general rule.The specialist aquariumIn this case, the hobbyist concentrates ona particular species, type, family, or groupof fish with common characteristics. Thechoice of this kind of aquarium can bedictated by several factors: interest inreproduction, the attainment of varietiesnot found in nature (sometimes for competition),or quite simply a fascinationwhich is difficult to explain. As in the previoussection, the fish and plants do nothave to come from the same region, andthe latter are sometimes merely secondaryelements.The Dutch aquariumIn this type of aquarium fish serve as a foilto the plants, which play the leading role,although the former do also contribute tothe equilibrium of the setting, which is noteasy to maintain. The plants and fish cancome from different geographical areas.The results can be ravishing, sometimesamounting to a veritable aquatic garden,with the aquarist becoming a horticulturistin order to maintain it.• Garden pond.Dutchaquarium.33

WATER, A HAVEN FOR LIFEAs its name suggests, this type of aquariumis highly prized in the Netherlands,and in Germany too, although it is little(too little?) seen in the rest of the world.Regional aquariumsHere the trick is to reconstruct as faithfullyas possible a natural biotope in whicheverything harmonizes: the water, the soil,the rocks, the plants, and the fish. The densityof living beings is higher than that of anatural setting, however. Mounting anaquarium of this type requires a certainknowledge of the geographical area concerned,to ensure the compatibility of thevarious elements.• Central American aquariumsThere are two possible options. The first isthe recreation of a habitat suitable for livebearersfrom the Poeciliid family: hardwater with a temperature of 26°C or more,and plants playing an important role. Thesecond is the assembly of a tank for Cichlids:rocky decor, a few hardy plants, withthe water fairly soft, well-filtered, and oxygenated.• South American aquariumsMainly devoted to the Amazon, these canbe divided into two main categories. Thetanks with limpid colorless water, neutralor slightly acid, are inhabited by smallCharacins that are somewhat difficult forThe elements of aSouth Americantank. •34

DIFFERENT TYPES OF AQUARIUMCharacins found on this continent, and certainCichlids. The typical plants in this environmentare Anubias.Tanganyika-type aquariums are characterizedby their calcareous and decidedlyalkaline water. They have few plants, asthese are often treated roughly by the fish,but they have a rocky setting, with hidingplaces and swimming areas to the liking ofseveral species of Cichlids.The general characteristics of aquariumsfor Mbunas from Lake Malawi are roughlysimilar.• Asiatic aquariumsRunning water Cyprinids can be kept in atank with clear water which is well-filtered,slightly acid, and soft, at a temperatureof 25-26°C. Barbs and danios arethe usual occupants of this type of aquar-

WATER, A HAVEN FOR LIFEAFRICA• Aquarium witha collection ofseveral speciesfrom Lake Malawi.West Africa is lined with rivers and streams with an acid pH, and temperatures of up to 27°C. Theswampy areas disappear in the dry season, but the fish which frequent them have devised variousstrategies to overcome this difficulty: some species, such as the killies, lay eggs which are able to resistdrought.East Africa is characterized by the presence of large lakes, veritable inland seas, only with unsaltedwater. The most important of these are, from north to south, Lake Victoria, Lake Tanganyika, andLake Malawi. They are mainly inhabited by fish from the Cichlid family, three quarters of which areonly found in this region.Lake Victoria, which stretches over nearly 7,000 km 2 , with a maximum depth of 80 m, contains veryhard water which can reach a temperature of 26-27°C. Its fish represent a substantial source ofnutrition locally, although they have been in decline since the deliberate introduction of a carnivorouspredator, the Nile perch.The lake most familiar to aquarists, Lake Tanganyika, is one of the biggest (31,900 km 2 , the secondlargest in the world) and the deepest (a maximum of 1,400 m!). Only the first couple of hundredmeters contain fish, which are accustomed to its extremely hard water, a pH between 7.5 and 9.2,and temperatures of up to 27°C. The clear, well-oxygenated surface waters house few plants, themain vegetation being the carpet of algae covering the rocky areas. The species living theresometimes form different population groups, quite close to each other, which can mainly bedistinguished by their color. Some fishes take refuge in the empty shells of Gastropods on the sandyshores. This lake is also exploited by the locals as a source of food, but the Cichlids are actively bredand exported all over the world.This is also the case with Lake Malawi, at 26,000 km 2 almost as large as Tanganyika, but not as deep(700 m). Its water is slightly less calcareous and its temperatures range from 24 to 26°C. Somespecies of Cichlids found there are nowadays known as Mbunas.36

DIFFERENT TYPES OF AQUARIUMSOUTH-EAST ASIAThe water in the rivers and streams is acid,sometimes colored, with temperatures oftenexceeding 25°C. The swamp and marsh areas areshallow, allowing the sun to exert a greaterinfluence, and their water temperature can behigher than 28°C. Natural sites collect rain andfloodwater, while the artificial sites consist of ricefields. The exuberant plant life is either completelyaquatic (totally submerged) or paludal (partiallyunderwater; in very wet environments, the baseof the plants is often submerged).Aquatic zone in Asia, colonized by sealentils. •Asiatic tank.The brackish water aquariumThis is characterized by water with lesssalt than the sea, pH values of between7.7 and 8, and fairly high temperatures,26-27°C. The decor consists of branchesand roots, but never rocks. Few plantssurvive in this type of water, and only afew species of fish can tolerate it (see thebox on Brackish water species, pages124-125).Tropical seawater aquariumsThe water must be of a very high quality:clear, therefore well-filtered and oxygenated.It can be natural or reconstituted.Roots tangledunderwater provideshelter for fish.MANGROVESThe borders between the sea and the landprovide muddy, swampy areas (often estuaries),in which certain trees - mangroves - plungetheir roots. Mangroves is also the collectivename for these tropical regions in Africa, Asia,and Australia. The water reaches very hightemperatures, of 30°C or more, and the seawater exerts a very strong influence. Thesalinity is therefore variable, leading to thepresence of fauna specific to these areas. Thebest-known occupant of mangroves is theperiophthalmus, an amphibious fish which candevelop out of water on account of the form ofits pectoral fins.37

WATER, A HAVEN FOR LIFEThe generousdimensions of thisaquaterrarium canhouse waterturtles as acomplement toseveral species offish38or a combination of the two. Marineplants are not common, but algae canappear spontaneously and cover thedecor of rocks or dead corals - althoughtheir growth is imperceptible to the nakedeye, it is fairly rapid. They are introducedto the aquarium in various ways. The soilis very grainy, as the sand is made up ofshells and corals.Under bright light, a marine aquariumoften forms a colorful environment inwhich fish develop among inert or livingdecorative elements, which they can sharewith invertebrates, including certainshrimps. Novice aquarists are oftenadvised not to plunge into keeping amarine aquarium without first findingtheir water wings in a freshwater tank,which is easier to tackle. The same ecologicalrules govern the two types of setting,however, the main differenceobviously being the salinity of the water.Let us just say that it is more sensible tostart with fresh water, as the plants andfish are more robust and their price isoften more accessible. To be realistic,problems with sea water, involving theaccidental loss of expensive fish, woulddiscourage many beginners. Nevertheless,apart from the price of marine fish - andthere are some cheaper species - it shouldbe pointed out that marine aquariums arenot much more expensive to run.The tropical freshwater aquaterrariumThese days aquarists are not just concernedwith water but often incorporatean adjoining piece of land. Thoughaquaterrariums are quite tricky to design,the results can often prove spectacular.The aquatic element requires skills similarto traditional aquarium maintenance,while the cultivation of its terrestrialneighbor is not that different from lookingafter houseplants, except in a very humidsetting. The former usually houses fish,but the latter can play host to amphibians,and even reptiles such as sea turtles.SPECIAL PURPOSE AQUARIUMSThis category includes:- breeding aquariums, often a simpleglued glass tank with no soil, for temporaryuse;- hospital-aquariums;- large aquariums. These are large byvirtue of their length, as their depth andbreadth cannot exceed certain limits fortechnical and practical reasons. Theysometimes present installation problems,due to the weight on the base and thespecial materials required for their construction.Large tanks are often given over to largespecies which require ample living spaceon account of their size. They can also beused for the other purposes mentionedabove, because it is generally consideredthat the bigger the aquarium, the easier itis to maintain its equilibrium. Contrary towhat is often thought, their maintenancedoes not imply more problems if an equilibriumis really achieved.

PUBLIC AQUARIUMSIn public aquariums, fishkeeping takes on a new dimension. The general trend is to offer the publicextremely large tanks, in which the behavior of the animals reflects as closely as possible what actuallygoes on in their natural habitat, usually beyond the reach of most people. These "living museums" servenot only to present aquatic animals but also to study them, as much still remains to be discovered aboutsome biological phenomena (for example, the reproduction of marine fish). This new generation of "realconditions" aquariums includes among its ranks the Deep-Sea World in Fife, Scotland, the Fenit Sea Worldin County Kerry, Ireland, and the Clearwater Marine Aquarium in Florida, not forgetting illustriousprecursors such as the National Aquarium in Washington and the Belle Isle Aquarium, Detroit, whichopened in 1873 and 1904, respectively.There are now literally hundreds of public aquariums in both Europe and North America, some of whichspecialize in the fauna of their local region,such as the recently opened aquarium inTouraine, France, the largest in Europe.Space does not permit an exhaustive list, butreaders can obtain information about publicaquariums from the Fish Information Service(FINS) (www.actwin.com/fish/public.cgi).Tropical lagoon tank in LaRochelle aquarium. •Freshwater room in the tropicalaquarium in Tours. •

FishThere are more than 30,000 species of fish, more or less evenlydistributed between fresh water and sea water, and of thesesome 1,500 are of interest to the aquarist. Fish embody a greatanatomical and biological diversity and richness, and this canbe clearly seen in aquariums.

ANATOMY AND BIOLOGYWhatever type of aquarium you choose, a minimal knowledge of theanatomy and biology of the species you are raising is an essential prerequisite.The information below, presented in layman's language, allows you to keep your fishin good health, in the best possible conditions, to feed them appropriately so that theycan grow, and to facilitate their reproduction — in short, to understand them betterin order to take better care of them.EXTERNAL ANATOMYHippocampuskuda.The bodyA fish is typically drawn as an elongatedspindle, and in fact this is the most commonform, as itmakes it easier toswim in openwater. These hydrodynamiccharacteristicspermit rapidacceleration andnot inconsiderablespeeds (sometimesup to 20 km perhour) in a medium(water) that offers acertain degree ofresistance.However, there areother forms, thatare also all connectedwith thelifestyle of the fishin question: bottom-dwellershave• Pterois volitans.a flat stomach, while those that live inwater obstructed by plants and brancheshave compact, thin bodies that enablethem to squeeze through the obstacles.This is equally the case with the countlessfish in the coral reefs, which thread theirway through the blocks of coral. Finally,there are certain fish that are unclassifiable,so varied and strange are the formsthey flaunt, although they always correspondto a particular lifestyle.The finsFish have several types of fins, each oneplaying a precise role. Their forms andnames are often used to classify them intodifferent families.Of the unpaired fins (i.e. consisting of asingle fin), the most noteworthy are thedorsal and the anal fins. These serve tostabilize the fish when it is not going veryfast or is coming to a halt, and they aretucked in when the fish swims morequickly. The caudal fin (incorrectlyreferred to as the tail) supplies propulsion,in conjunction with the rear part ofthe body. In some species, particularly theCharacins and the catfish, there is a smallextra fin between the dorsal and the caudalfins, known as the adipose fin.42

although this is not really used. Thepaired fins, attached symmetrically toeach side of the body, are called pectoraland pelvic fins. They are used for stabilizing,stopping, slowing down, or changingdirection: vertically, from the water surfaceto the bed, and vice versa, from sideto side, from left to right, from right to left.Fins consist of a membrane stretched onspokes, and they can all be tucked inalong the body, with the exception of thecaudal fin. The adipose fin is merely afold of skin, without any spokes. Whenthe spokes are longer than the fins theyare known as spiny fins, and they can representa danger to the aquarist, as in thecase of the scorpion fish, for example.The mucus, skin, and scalesFishes' bodies are covered with a mucusthat plays a double role: it reinforces thehydrodynamics by "smoothing" the skin,and it affords protection against the penetrationof parasites or pathogenic elements.The latter point is extremelyimportant, and it explains why fish mustnot be moved by hand: this risks damagingthe mucus and facilitating the developmentof certain diseases.Male fightingfish (Bettasplendens).SPECTACULAR FINS MAY BE NURTURE NOT NATURESome aquarium fish have fins that are very different in shape orsize from those that are found in nature. They are the result ofpatient breeding carried out by aquarists over a period of years.The visual effect is guaranteed, but the fish's behavior is sometimesaltered, especially its velocity when moving around. Fishwith large fins in the form of sails have little more than a remoterelationship with their wild cousins, which have gone out of fashionand are no longer to be seen in tanks. The purpose of theseselections can sometimes be in doubt: they undeniably result inhighly attractive fish, butwhat advantage do theyhave over other stunningnatural specimens?Contrary to a widely held belief, the scalesdo not stick out of the body but are anintegral part of the skin, and they are visiblethrough a fine layer of transparentepidermis. When a scale is raised, damaged,or torn off, the skin itself is equallyaffected and becomes vulnerable to theaction of pathogens.ColoringEvery fish has a basic coloring that can bemodified. Their shiny, metallic appearance,derived from the crystals present inthe cells of the skin, varies according toXipho (Xiphophorus helleri),bred with overdevelopedfins. •the direction of the light striking them. Afish's color is a result of the different pigmentslocated in the epidermis. These canchange, slowly, for reproduction and camouflage,under the control of hormones,or more quickly, for flight or aggression,Some species offish are protectedby the bony platescovering their headand bodyEuxiphipopsnavarchus.43

FISHCOLORING: PROTECTION, WARNING, AND SEDUCTIONCertain fish, such as this murena, have verysharp teeth, indicating that they are predators.The black bands of the scalare enable it to hide.The coloring of a fish varies according to its age and mood. Somefish living in coral reefs reject individuals of their own species ora related species with a coloring similar to their own(Pomacanthids, also known as angelfishes, for example) becausethey consider newcomers as enemies wishing to appropriate theirterritory and their food supply. This is why their offspring have avery different coloring from that of adults, so as not to be consideredintruders. In their desire to protect themselves, some fishadopt a camouflage to merge in with their surroundings, or, incontrast, reduce the intensity of their color to pass unnoticed.Thus, the vertical black stripes on the scalare allow it to hideamong submerged branches and plants (see drawing above).In some species, the male and female sport very different colorings,enabling them to be distinguished - a gift of nature muchappreciated by aquarists! This is true of a large number of theCichlids in the African lakes. At mating time, the male can flauntvivid colors, not only to seduce the female in the courting ritualbut also to impress his rivals and scare them off. This occurs withthe meeki, a Central American Cichlid - the underside of its headturns red at mating time.The coloring offish exists notmerely to satisfythe eye; it playsan equallyimportant socialrole. •controlled by nerves. The coloring of afish can also vary when it is suffering fromdisease or nutrient deficiency.The headWhatever its form - conical, elongated, orstocky - the head houses someimportant organs:- first of all, there are the eyes,which have no eyelids and arehighly mobile. This mobility,coupled with theirposition on the side ofthe head, allows a fish tocommand a broad field ofvision - around 270°. Incontrast, the clarity of itsvision is unexceptional:beyond a certain distance,• Fish have ait distinguishes massesparticularly wideand forms rather thanfield of visiondetails. Fish are very sensitiveto variations in light - detecting lowintensities of light, such as that of themoon - and they can recognize colors.- next comes the mouth, with a size andshape related to its feeding habits. Carnivorousfish generally have a large mouththat can open wide and is endowed withan array of pointed teeth, which are sometimescurved towards the back to keephold of their prey. Omnivorous and herbivorousfish have a smaller mouth, withflat teeth ideally suited to grinding food.44

ANATOMY AND BIOLOGYThe position of the mouth cansimilarly reveal eating habits:• a mouth in the upper positionindicates a top-feeder;• a mouth in the terminal positionis the sign of a fish that huntsunderwater;• a mouth in the lower positionindicates a bottom-feeder.BreathingWater is aspirated through thefish's mouth, passes through thebranchiae and is expelled due tothe movements of the operculum,which covers them. There isalways some water washing thebranchiae of the fish.Oxygen requirements are not directly proportionalto the size of the fish, with thesmallest species being the greatest consumersof oxygen: ten fish weighing 1 geach consume more oxygen per gram ofbody weight than one fish of 10 g.The barbelsFish that live on the bed or in dark environments(colored or turbid water) havebarbels around the mouth (Corfdoras,Botia, for example).These appendages have a tactile and sensoryrole. By complementing or replacingthe eyes, they enable the fish to detectpossible sources of nutrition.The nostrilsTwo or four in number, these arelocated in front of the eyes. Theyplay no part in respiration but,extended inside the head by anolfactory sac, they perceive andanalyze smells.The operculumThis protects the branchiae andguarantees the circulation of waterthrough the regular movements ofthe valve, ensuring that thebranchiae are always in contactwith the water from which theyextract oxygen. The term "gills".• The mouth ofthis marine fish(Forcipigerflavissimus, theyellow longnosebutterfly) allows itto capture its preyin the crevices ofthe coral.The glass siluriddetects its foodpartly as a resultof its barbels. •45

FISHINTERNAL ANATOMY• The blind tetra(Anoptichthysjordani) does nothave any eyes butdetects its preyand enemies withits lateral line.sometimes incorrectly used, refers to theopening produced by the movements ofthe operculum, which serves as an exit forthe water that has irrigated the branchiae.The lateral lineRunning symmetrically along each side ofthe fish's body, the lateral line is more orless visible, according to the species. Itconsists of a succession of pores that communicatewith a canal situated under theskin. This important organ does not existin any other vertebrates.While the senses of taste and smell, highlydeveloped in fish, allow them to recognizea greater number of smells thanhumans, at very low concentrations, thelateral line, with its special cells, detectsand analyzes the vibrations of the waterand sends this information to the brain. Inthis way a fish can be aware of the proximityof an enemy, of a prey... or of theapproach of the aquarist (see box, p. 47).The importance of the lateral line isapparent in the blind tetra (Anoptichthysjordani), which never bumps into anobstacle even though it has no eyes.The sum of the internal organs accounts forroughly 50 to 60% of the body weight in aclassically shaped fish.The brainThis is fairly simple in fish, when comparedto other more evolved animals. Theparts corresponding to sight and smell areparticularly well developed, demonstratingthe importance of these two senses.The skeletonObviously, this supports the fish's body,but it is less sturdy than that of a land animal,as a fish, partially freed from gravity,is "carried" by the water. Nevertheless, therelative fragility of the skeleton is a handicapand it is not uncommon to find frythat emerge from their egg "twisted".The respiratory and circulatory systemThis system is highly distinctive. The bloodloaded with carbon dioxide is pumped bythe heart to the branchiae, where it is oxygenated.Nature has provided fish with46eight branchiae (four on each side), eachmade up of two leaves. The total surfacearea of these essential organs, whenspread out, would be nearly equal to thatof the fish's body. The vivid red color ofthe branchiae is due to their abundant irrigationof blood; a darker color is a symptomof a respiratory problem. Thebranchiae are fragile organs, susceptible todamage from suspended sediment or parasites,resulting in a reduced intake of oxygen,with all its unfortunate consequences.After traveling through the branchiae, the

ANATOMY AND BIOLOGYvivid red blood, rich in oxygen, irrigatesthe body, and the oxygen goeson to break down the foodstuffs inthe organs.The fish in the Belontiid family,which live in water in which the oxygenis sometimes rarefied, have aspecial organ for trapping atmosphericoxygen.The digestive systemThis has no special characteristics,apart from the fact that the stomachcan stretch to hold large prey, especiallyin carnivorous fish. This is wheredigestion starts, and it then continuesin the intestine. With large prey theprocess can last several days, but in anaquarium, with artificial food, it willnot take more than a few hours.The excretory systemThis allows undigested matter to be evacuatedthrough the anus in the form ofexcrement, or feces. The urine is formedin the kidneys, situated under the spinalcolumn; it is evacuated through the urinarypore. It is worth mentioning that fishalso excrete nitrogenous substances viathe branchiae. All excreted substancescontain nitrogen and are toxic for animals,but in a well-balanced aquarium they areeventually converted into nitrates and thuscause no harm.The swim bladderFish have a swim bladder, also known asan air bladder. This is an organ connectedDO FISH RECOGNIZE THEIR OWNER?Countless aquarists have noticed that some oftheir fishes react more enthusiastically to theirpresence than to that of strangers. If they do"recognize" the person who looks after them,how do they do it? They are capable of distinguishingthe special characteristics of thevibrations caused by the footsteps of such andsuch person, which are transmitted to thewater of the aquarium. Not only that, theirsense of sight, although not perfect, helpsthem in this task of "recognition."to the digestive system, which fills up withgas and helps fish to regulate their flotationwhen moving between two different typesof water. They empty it to dive and fill it upwhen they need to come nearer the surface.Bottom-dwelling fish generally have asmaller swim bladder, or none at all, asthey rarely swim in open water.The reproductive organsMales have two testicles that are linked tothe vas deferens. while females haveovaries extended by the oviducts. In bothcases the sexual products - the spermatozoaand ova - are expelled via the genitalorifice. As the fertilization of the eggs isexternal and takes place in the water, thereare no organs for coupling and fertilization,except in the case of livebearers.• In Poeciliids(livebearers), theanal fin in themale (below) istransformed into acoupling organ.Which of the two recognizes the other first? •47

FISHDO FISH SLEEP?When an aquarium is abruptly switched on in the morning, it isnoticeable that its occupants do not immediately resume theirnormal activity. Some of them are on the bottom of the tank,some in the plants, and others remain almost immobile in thewater. It is difficult to speak of sleep in the generally acceptedsense of the word, but it is certain that fish have periods of restfulness,of varying degrees. This can be verified at night, with theaid of a small flashlight: the fish are practically stationary (apartfrom nocturnal species), but their eyes are not closed as theyhave no eyelids.DO THEY FEEL PHYSICAL PAIN?The sensation of pain is sent to the brain via the sensory nerves.As fish are endowed with the latter, it can be assumed that theyfeel pain when they are hit or wounded, and perhaps even whenthey are sick.A Fish with aclassical shapemove forwards bypropellingthemselves withthe rear part ofthe body.BIOLOGYSwimmingIt is essentially the rear part of thebody, particularly the caudal fin,which serves to propel thefish, while the other finsplay a stabilizing and steeringrole. Of course, themore hydrodynamic a fish'sform, the more it is capableof setting off abruptly and swimmingquickly, indispensable for catching preyor fleeing an enemy.Aquarists are sometimes advised not to letquick and lively fish (like Barbs) cohabitwith slower and more placid species (likeloaches), as the latter may be frustrated intheir attempts to eat the food provided bytheir owner.BehaviorFishes' behavior in an aquarium reflectstheir lifestyle in a natural habitat, albeitmodified by the fact that they are living ina more cramped environment, cominginto contact with other species morequickly and easily. Fish from the samespecies can behave differently from oneaquarium to another, according to thecapacity and the other occupants.• Territorial behaviorWhen fish are in their original biotope,their territorial behavior is reproduced incaptivity, and is sometimes even intensified.A territory is a living space - eitherpermanent or temporary (as in the reproductionperiod) - with an extension proportionalto the size of the fish. Itsoccupant rebuffs individuals from thesame species, from related species, oreven from totally different ones. The surfacearea must be sufficient for the fish tofind refuge, foodstuffs, and fish of theopposite sex with which to reproduce.With some fish, particularly marinespecies, it is important to plan a territoryin the aquarium that will provide sheltersand hideaways.• Group behaviorStrength is to be found in unity, and livingin a group permits a better defenseagainst enemies. Indeed, from a distance agroup or school of fish takes on theappearance of a mass that is capable ofSome fish live ingroups, whichmakes it easier notonly to defendthemselves butalso to reproduce.•48

ANATOMY AND BIOLOGYsurprising and intimidating an enemy.Group life also facilitates reproduction, asan individual has a greater chance of findinga fish of the opposite sex. A group'sunity and organization are governed by aseries of signals which are invisible tohuman eyes: the use of the lateral line, forexample, prevents fish from colliding witheach other.• Dominance behaviorThe biggest members of a species dominatethe smallest ones: when the latter getbigger they are ejected from the territory.Dominance behavior has practical andsocial implications, as the dominator willhave priority in food and the choice of afish of the opposite sex. At the bottom ofthe social ladder, the most dominated fishis permanently subject to aggression andharassment and has to hide most of thetime, with its growth being prejudiced asa result. This is the case with some speciesof African Cichlids.• Prey-predator relationshipsSome fish feed on other smaller ones in anatural habitat, giving rise to incompatibilitiesin an aquarium: take care, forexample, not to let South American Cichlidscohabit with Characins.• AggressionSometimes an aquarium is a stage foraggression between different species. Thisaggression is always justified, as it isrelated to the defense of territory or offspring.It is a problem of space - thesephenomena are rarely seen in big aquariums.However, a new fish introduced intoa tank will often be considered as anintruder, or prey, and will be harassed.majority of fish. Some patriarchs live tothe ripe old age of ten or more - these arelarge fish, particularly marine species. It isvery difficult to postulate an optimal lifespan for a given species in captivity, asenvironmental conditions introduce toomany variable factors.• In nature, thebiggest fish oftenfeed on smallerones - obviouslysomething toavoid in anaquarium.Growth and longevityUnlike human beings, fish continue togrow throughout their life, quickly at first,and then more slowly with age.The size of fish in aquariums is mostlysmaller than that found in the wild,undoubtedly as a result of the restrictedliving space at their disposal. This can easilybe put to the test: an individual whosesize has seemingly stabilized starts togrow if it is put into a bigger tank.As regards longevity, this varies accordingto the species: a year, more or less, for thesmall species, and two to five years for theHOW TO REDUCE ACTS OF AGGRESSIONIN AN AQUARIUM?Only put together those fish which are known to be compatible,particularly in the case of marine fish, and give them asmuch space as possible. Be sure to provide a number of nooksand crannies, appropriate for the dimensions of the residents.Another solution is to mix species with different lifestyles - forexample, free swimmers (like Barbs and Danios) and bottomdwellers(like loaches) - that will not compete with each other.49

FEEDINGFood must provide fish with the elements needed to "build" theirbody (proteins) and the energy (from proteins, carbohydrates, and lipids)required for its smooth functioning. Feeding a fish properly ensures thatit will grow satisfactorily, as well as facilitating its reproduction and helpingit to combat disease. Quality and quantity are two important concepts in feeding:an aquarist must learn to avoid over-feeding and to diversify the food supply.DIETS AND NUTRITIONALREQUIREMENTSWith regard to fishes' feeding habits anddietary requirements, there are three maingroups:- carnivores, which feed on worms, crustaceans,insects, or other fish;- herbivores, with a diet mainly comprisingFOOD PORTIONSThere is a tendency to overfeed aquarium fish andproduce some rather flabby specimens. Moreover, there is anincreased risk of pollution in a confined space: the more a fisheats, the more it excretes nitrogenous substances, and that iswithout counting the foodstuffs that quickly decompose in thewater in the aquarium.An adult fish only eats 1 or 2% of its own body weight per day,although a juvenile consumes twice that amount. Very lightflakes involve little risk of overdosing, in contrast with otherfoodstuffs which can sometimes slip out of the hand.Whenever possible, it is advisable to divide the daily input intoseparate portions, twice a day for adults, more often for fry.As fish in their natural habitat are unlikely to eat regularly everyday, most aquarium fish will therefore cope well with a shorttermfast. Some aquarists impose a one-day fast per week tocompensate for the likelihood that the fish have been overfedon the other days. Fasting is however not suitable for fryas it may slow their growth considerably.Specialist aquarium stores supplyartificial fish food in a variety offorms and sizes. •vegetable matter (plants, algae) whichthey graze or grind;- omnivores, which have a very varieddiet as they eat both animal prey and vegetablematter.In practice, diets are not always so easy todefine. In a natural setting fish eat whatthey find, and so sometimes a herbivorewill eat a small animal taking shelter inthe plants that it normally eats.Carnivorous fish mainly require proteinsand lipids, while herbivores have a specialneed for carbohydrates, and omnivoresdemand a mixture of proteins, carbohydrates,and lipids.Bearing in mind the limitations of thesedefinitions, all three diets can be foundamong those given to aquarium fish,although there are some exceptions.The aquarist should also take care thatvitamins and mineral salts form part of avaried and balanced diet, especiallythrough the addition of fresh or live food.A wide palette offoodstuffs stimulatesthe growthand reproductionof theaquarium'sinhabitantsand strengthenstheir resistanceagainst disease. Assuch, it is the bestprecaution that can betaken against disappointing results andlack of success.50

FEEDINGARTIFICIALFOOD• Flakes ofvegetable matter.This is dry food whichis commercially widelyavailable in specialistaquarium stores.In the last twenty yearsthe entire range hasdiversified considerably, and today thereis a wide variety, adapted to the needs ofdifferent groups of fishes: for juvenile andadult fish, for freshwater and seawaterfish, etc. These foodstuffs are characterizedby a high level of proteins (generally40-50%) and come in different forms: inflakes (the most common), granulated, orcompressed.The flakes float for a while beforethey sink, which makes them easierto grasp for surface and openwaterfish. There are obviouslyalso different sizes of foodstuffs,according to the size ofthe fish's mouth. This artificialfood is fragile and deterioratesif it is not kept in the correctconditions. It must therefore bestored in a dry place protected from thelight. Its composition is only guaranteedfor a certain period, so it is advisable tobuy a small box if you have only oneaquarium and a few fish.Some aquarists do not hesitateto give their residentstrout food, which they buyat fish farms. This food isvery rich in proteins andlipids, thus ensuring the• Flakes forguppies.rapid growth of troutbred for eating, but thisis not vital in aquariums.Although suchfood contains pigmentsintended tochange the flesh colorof salmon fish, aquaristswho have used ithave not reportedany modifications inthe external color ofFlakes for adult herbivores.Artificial foodmust becomplementedwith live prey orfresh food.their fish. In any case, this foodcan prove very economical forlarge-scale breeding or garden ponds.Marine fish sometimes refuse artificialfood, either for a short period after theirintroduction to the aquarium, or on a permanentbasis. One trick is to progressivelyincorporate increasing amounts of commercialfood along with fresh food or liveprey. This gradually accustoms the fish toits smell and taste until they finally acceptit on its own.DIFFERENT TYPES OF FOODFOR AQUARIUM FISHTypicalartificial food foradults.The artificial foodstuffs currently on the market are very effectivefor aquarium fish. In order to cover their needs as fully aspossible, fish can also be served small, live prey, which are similarlyavailable commercially and are an important source of vitaminsand mineral salts. There are other possible options: whitemeat and mussels, for example.51

FISHArtificial food in the form oftablets.Freeze-dried mussels.Beef heart, similarlyfreeze-dried.• Frozen food:crab andphytoplankton.FOODSTUFFS OFNATURAL ORIGINFreeze-dried foodIt is possible to buy freeze-driedfood items - small animals,shrimps, worms, or plankton -in which the water contenthas been greatly reducedso that they can be preservedmore effectively.This treatmentdoes clearlyAmake them expensive, butthey are at least as nourishingas flakes and verypopular with fish. Theymust be stored in a dryplace. Feed them to the fishaccording to the manufacturer'sdirections and do not exceed thequantities recommended.Frozen foodFrozen products - shrimps, fish, worms,and plankton - can also be used, oncethey have been separated and rinsed.They have a very high nutritionalvalue, as freezingdoes not modify theircomposition. They areobviously stored in thefreezer and must not berefrozen after thawing, in order to reducethe risk of microbial contamination. Theyare more expensive than freeze-driedfoodstuffs.Domestic food itemsFinally, domestic food can be providedfresh or after freezing andthawing. It is best to avoid redmeats as they have too much fat.Beef heart, rich in both bloodand lipids, can only be givenonly to large fish. White meatsare preferable: chicken, turkey,or ham. As for seafood, whitefish can be used - although itmust be handled with care, as itcan break up in the water - as well as mussels,cockles, and shrimps, which can bebought preserved naturally. Vegetables aresometimes needed for herbivorous fish: lettuceor spinach that has been blanched, i.e.out into boiling water for a few minutes.Freeze-dried shrimps.Cubes of freeze-driedtubifex worms.52

FEEDINGLIVE PREYThese are ideal food items for carnivorousfish: they retain all their nutritionalvalue and move around to attract thefish. They are a problem to keep as theyonly last a few days, but they can befrozen.DRIED DAPHNIASThese were once very popular - so many aquaristshave started with them! Nowadays they are out of fashion; infact they are not the ideal food for fish and it is best not to usethem. More complete and suitable products, particularly thosein the form of flakes, are now available, even for goldfish.LIVE PREY AND HOME PREPARATIONSThe artificial food on the market these days is very effective for aquarium fish. To diversify andbalance their requirements, they can also be served some of the small, live prey that are commerciallyavailable - an important supply of vitamins and mineral salts - or fresh food or homemademixtures.One of the best fresh foods: musselsThis mollusk, prized by humans, is equally appreciated by fish, especially those marine speciesthat refuse artificial food. Widely available, inexpensive, easy to freeze, mussels are a top-classdish: they are rich in proteins and carbohydrates, with few lipids. Furthermore, they containmany minerals (such as calcium, phosphorus, magnesium, iron) and even vitamin C, whichplays an important role in the fight against disease. Mussels must be well cooked before usingand their shells and connective filaments removed.Cut them into pieces before distributing or freezingthem.Homemade foodAn aquarist can easily make his or her own fishfood - the possibilities are enormous. The followingrecipe is just one of many.Take some cooked white meat (chicken, turkey,ham) and some seafood (mussels, cockles), alsocooked, and mince them with a little water tomake a homogenous paste. A vitamin supplement,available from aquarium stores, can beadded during this process.This mixture can then be mixed with gelatin (froma sachet of powder, for example) so that the pastedoes not break up in the water, as this maybecome a source of pollution. One portion can bedistributed immediately, while the rest can easily be frozen in ice trays. The models designedfor small ice cubes are particularly recommended for making a large number of small portions.Once frozen, they can be slipped out of the ice trays and bagged up in freezer bags for use asrequired.• Cookedmussels, frozen orotherwise, provideboth practical andnourishing fare.53

FISHTubifex in anatural setting. •Tubifex worms canbe distributed tofish by means of aspecial accessory.54BloodwormsIn fact, these are not worms but theaquatic larvae of various species of nonbitingmosquitoes. They are also commonlyused as bait in fishing. Although itis sometimes thought that they live inmud, they are actually found in the waterof areas that are well endowed withorganic matter. It is useless trying to collectthem yourself, but they are sold in theaquarium trade. They keep for a few daysin the refrigerator, wrapped in moistnewspaper. They are a good source ofnutrition, as they are rich in protein.Tubifex wormsThese are worms that are gathered from themud in environments rich in organic matter.Some people think that they represent arisk when they areintroduced into anaquarium, as theymay carry undesirablebacteria.This risk is veryslight, however,and there havebeen no reports ofany serious incidents.The specimenswhich arecommercially availablecan be kept for a few days in therefrigerator, in domestic water, but it isRich in proteins, bloodworms are a prey muchappreciated by carnivorous fish.essential that thiswater is changedevery day.ShrimpsFlowing and welloxygenatedfreshwater are home tosmall river shrimpsof up 2 cm thatswim along thebanks. These arerarely sold live, butthey can be found in a freeze-dried form.You will find that your fish will definitelyenjoy them.The small marine shrimpsfound on some coasts arealso highly prized, especiallyby marine fish.These are often sold infishing stores along thecoast. If you are luckyenough to live in such anarea, you can also collectthem yourself and keepthem in an well oxygenatedseawater aquarium.Both types of shrimpscan be frozen after beingcooked and rinsed underthe faucet, or they can alsobe ground and turned intoa homemade dish (seebox, page 53).

FEEDINGCoastalshrimps, live orcooked, arerecommended farefor big fish.Small fishEither fry or small fish can be used to feedmarine fish doubtful about artificial food,or large freshwater fish. With this in mind,some aquarists breed prolific species thatreproduce easily (Poeciliids, for example).Other live prey (larger than 1 cm)Keeping and breedingworms or insectlarvae is also possible,though it sometimesproves time-consuming.The range of liveprey listed above isadequate for theneeds of your fish.Planktonic foodFreshwater or marine plankton contain ahost of organisms barely visible to thenaked eye (0.1-1 cm) but valuable forfeeding fish, especially the fry. Collectingthem in a natural setting is tiresome, andinvolves a risk of introducing potentialmicroscopic hosts into the aquarium andspreading disease. Some planktonic foodis available on the market in frozen form.Brine shrimpsThis is the "magic" food that every aquaristshould breed. This primitive crustaceangrows to 1 cm when adult and is calledArtemia salina.They live in the heavily saline waters ofsalt marshes, feeding on the micro-algaethat they gather with their filtering legs.Their characteristic most relevant to theaquarist is that their eggs can be storeddry, with their developmentinterrupted,for use later on. Oncethe eggs are returnedto salty water, theyhatch rapidly andArtemia salina(Brine shrimp)nauplii (below):these areindispensable forfeeding the fry ofmost species offish.55

FISH• Some clubsbreed rotifers,vital food for thefry of marine fish,especiallyclownfish.Copepods, amongthe constituents ofnatural marineplankton, form thebasis of the diet ofcertain fish.56produce a larva called a nauplius, whichmeasures only 0.3 mm and is particularlysuitable for feeding to fry.Feeding brine shrimps to fish is easy, evenfor an amateur (see box). They are stilltoo big for the fry of some fish, however,especially marine species. In such cases, itis possible to use rotifers, animals halfwaybetween worms and crustaceans, whichhave a crustacean-like shell and nevergrow to more than 0.2 mm.RotifersThese are more complicated to breed thanbrine shrimps, as they must be fed planktonicmicro-algae which also need to becultivated. It is therefore best to obtainthem from a laboratory specializing inoceanography or marine biology, and toget advice on the essential steps requiredto look after them for a few days - thetime within which the fry for which theyare intended will be big enough and sufficientlydeveloped to move on to a dietof brine shrimp nauplii.FOOD DISTRIBUTIONWhen they are healthy and well adjustedto captivity, fish eat at a regular time andbecome accustomed to the spot where thefood is given out. It is advisable to dividethe daily ration into two parts - one in themorning and one in the evening, forexample. The end of the day - 1 or 2hours before turning the aquarium lightingoff - is usually the most practical forthe aquarist. In any event, food distributionoffers a special opportunity toobserve the behavior of your residentsand check their state of health. Allowingthe fish to come and feed out of yourhand is particularly enjoyable, but takecare, because some large specimens haveimpressive teeth!If the water is too agitated, artificial or naturalfood may be dispersed too quicklyand washed to a corner of the aquariumwhere the fish will not be able to recoverit. thereby creating a potential for pollution.The stirring of the water must thereforecease when food is being distributedand eaten.Feeding the fryWhen they are born, the fry of egg-layingfish feed on the reserves in their vitellinvesicle, as their mouth does not open untila few days later. Theywill then often acceptthe fine powderswhich are availablecommercially.If this is not the case.give them brineshrimp nauplii for afew days - newlyhatched nauplii aremost suitable for thefirst two days. Afterthat, they can beoffered nauplii that are48 hours old.Daily production overa period of severaldays must therefore beplanned for. If brine

FEEDINGBREEDING BRINE SHRIMPSThe dry eggs (known as cysts) are available in aquarium supply stores. Theymust be kept away from light and moisture. In order to make them hatch, saltwater must be prepared with the following characteristics: temperature 25°C, salinity35%, i.e. a specific gravity of 1.023.The salt water can be natural or reconstituted with special aquarium salts, or even withrough kitchen salt (easier for aquarists who do not keep marine fish). The water can becolder and less salty (up to 20°C and 20%, i.e. a specific gravity of 1.014), but the hatchingrate will be lower (50-60% against 80-90%). Any small glass or PVC containercan be used - bottles, for example - although specialist equipment is available. The eggsare placed in the still water for a quarter of an hour, the time requiredfor their rehydration. If we estimate that 250,000eggs weigh around 1 g, a tiny amount(the tip of a knife, for example) willproduce sufficient brine shrimps.Aerate the water slightly toproduce small bubbles,which will disperse the eggs,but be careful not to stir the water toovigorously, otherwise some of the eggswill crash against the sides of the containerand will not hatch. The hatching• Equipment available inaquarium stores for hatchingbrine shrimps.occurs after 24-36 hours at 25°C, or afterup to 48 hours at 20°C. Finally, switch off the aeration: theempty shells will float to the surface, the unhatched eggs willfall to the bottom, and the brine shrimp nauplii will be swimmingjust under the surface. It is then easy to siphon them off (with anaeration pipe, for example) and strain them through a small filter (available commercially), or, alternatively,through the thin mesh of a piece of old curtain, or even a very fine pantyhose. To makethis operation easier, you can group the nauplii together using a flashlight, as they are attractedby light. You can then go on to feed them to the fry. They will only survive for a few minutes outsidesalted water, and they will not eat on the first day after hatching. If you want to keepthem for several days to obtain larger or more mature larvae, special food is commercially available.This makes it possible to keep brine shrimps until they are adults.Hatching brineshrimp eggs ingently stirredwater.A Collectingbrine shrimpnauplii throughsiphoning.ADULT BRINE SHRIMPSAdult brine shrimps are sold live in small sealedsachets containing salt water and air. They are passedthrough a sieve before being given to the fish,which enjoy hunting them down. They survive fora few minutes in unsalted water. Brine shrimps canalso be bought frozen.When feeding, it is important to avoid anyoverdosing, whether with artificial food or live prey,such as the adult brine shrimps pictured here.57

shrimps are unavailable, another option isthe production of infusorians. Live-bearingfish (the Poeciliid family) accept artificialfood from birth, and they also thriveon brine shrimp nauplii. As for marinefish, rotifers, discussed above, should beAutomaticfood distributor forartificial food. Eachsection correspondsto a daily dose.used, as theyeasily fit into thesmall mouths ofthe fry.InfusoriansThese are microscopic, unicellular animals,easy to produce in fresh water. Theyare usually present in small numbers in anaquarium.Riccia, a surface plant, gives them achance to grow, as they find food (organicmatter)on its leaves. They can also beproduced by leaving a piece of potato, alettuce leaf, or some paddy rice(unhusked rice, available in grain stores)to soak in a receptacle containing aquariumwater.• In captivity, the fry can be fedwith brine shrimp nauplii and thenwith fine commercial powders.lost in its new environment. Small speciesand more lethargic fish are often dominatedby their bigger and faster cohabitantsat feeding time. They must thereforealways be fed separately, preferably withmobile, live prey, once the other fish havebeen distracted by other food.A fish can also refuse to eat if it is sick,and this will be reflected in its behavior,color, and other symptoms which mayeventually be seen on its body. In this situationit must be isolated in anotheraquarium, treated, and given rich food.What if a fish does not eat?Sometimes a fish refuses to eat, or appearsto be incapable of doing so. It is thereforea question of finding the cause and eliminatingit. A newcomer to a tank rarely eatson the first day. This is normal, as it feelsGOLDEN RULES FOR FEEDING- Give fish a varied diet;- give them a little, but often. Two portions a day is ideal. Forfry, the feeding can be more frequent.- do not wait until the fish are sated and stop eating. Stop feedingonce the ration is complete;- siphon off any food surplus as quickly as possible, as theleftovers are pollutants.• Paddy rice can be used to produceinfusorians. It is "sown" on the bedor placed in a tubifex worm "feeder".58

FEEDINGcomprised of live prey or fresh produce.Sometimes fish can systematically refuseto eat artificial food, although this is rarein fresh water, but less so in marine aquariums.There is no point in being stubborn:change to a varied diet based on live preyand homemade fare.A MIRACLE FOOD FOR FRYA hard-boiled egg yolk is addedto water in a glass. This forms microparticleswhich are then sieved.This nutritious liquid is then given to thefry, taking care not to put too much intothe tank, as it is always important to minimizepollution. Egg yolk, rich in proteinsand lipids, can be used as a complementor as a replacement for other food.• Preparing defrosted food before feeding it tolarge fish.• Some aquaristsuse oysters tonourish their fish,which seem toenjoy them.

REPRODUCTIONIn the world's temperate regions, the reproduction of fish generallydepends on the season: in other words, it is determined by the temperature.There is only one high season, during which a species usually reproduces only once.In a tropical setting, where variations in temperature are less important,other factors influence on reproduction, especially rain. Fish can lay eggsseveral times a year, at intervals of sometimes less than a month.Pair ofHemichromisbimaculatus (jewelcichlid) surroundedby their young.60THE KEYS TO SUCCESSFULREPRODUCTION- Have well-fed and healthy parents.- Provide them with the best possibleenvironment:• a rearing tank;• high-quality water, with characteristicsas close as possible to their native setting.- Anticipate how you are going to feedthe fry.GENERAL PRINCIPLESMost fish kept by aquarists are oviparous(egg-layers), but there are some exceptions- viviparous fish (or livebearers).A varied and rich diet enables fish to accumulatereserves of proteins and lipids,which help them form eggs and spermatozoa.This is the maturing phase. When thefemale's ovary swells, she is ready to layeggs. This only needs a stimulus to triggerit off, such as, in the natural setting, rain,sunlight, or moonlight (research ispresently in progress on the influence of

REPRODUCTIONthe moon on reproduction). In an aquarium,egg-laying is sometimes sparked offby the early morning sunlight, which beatsdown on the tank with varying degrees ofintensity, or by a partial change of water.The laying of eggs can be preceded by acourting ritual, during which the maleseduces the female or, in rare cases, bulliesher and violently sees off any rivals.The female then expels her eggs into thewater, and these are immediately fertilizedby the male.This is obviously only a general descriptionthat leaves room for the huge diversityfound in aquarium fish, particularly asregards the future fate of the eggs: theycan be abandoned, or even sometimeseaten, by their parents, or they can beguarded and defended in the first days oftheir life, and a similar variety of parentalbehavior is found in the treatment of thedeveloping fry.The incubation of the eggs, which lastsseveral days, sees the development of theembryo. When this is completely formed, itmoves about until it breaks the egg's membrane:this is the hatching. A larva emerges,differing from an adult in its form, size, andthe proportion of certain organs. The larvahas highly developed eyes, for instance,allowing it to spot its prey. It also has avitellin vesicle, which provides it with foodreserves during the first days following itsemergence from the egg (except in livebearersof the Poeciliid family).The larva gradually evolves, over thecourse of a few days or weeks, dependingon the species, and modifies its behaviorto become more and more like an adult. Itturns into fry.Some fish laytheir eggs on ahorizontal support,then ventilate andprotect them fromthe rapaciousnessof other species.The vitellin sack ofthese 15-day-oldlarvae has beenpractically allused up. •THE VITELLIN SACK4 -juvenileThe vitellin sac, or vitellin vesicle, constitutesthe fish larva's food reserves in the first daysof its life. It derives from the vitellin of theegg - the equivalent of the yolk in poultry -accumulated by the female over the courseof the maturing process. It is sent along theblood vessels, which distribute these reservesaround the body of the larva. This allows it tosurvive until it is able to catch prey itself, i.e.a few days after emerging from the egg.61

THE REARING TANKThis is normally modest in size, as it is used to isolate a pair ofreproducing fish and their future offspring. There is no need for a bed,except for some species (the Cichlasomas, for example). A rearing tankmust be heated but only moderately filtered. Avoid any systems which may"swallow" the eggs and the fry. Aeration is not obligatory. Fill the tank withwater taken from the parents' aquarium, which can then be gradually modifiedto obtain the precise characteristics required by the reproducing fish(pH and hardness). A support should be provided for the egg-laying, andthis can be either natural (plants, rocks) or artificial (PVC). More detailedinformation on this subject, family by family, can be found below.This female Cichlid, which incubates her eggs in her mouth,finds greater peace in a rearing tank. •Sometimesreproduction takesplace in acommunal tank,catching theaquaristunawares.62REPRODUCTION STRATEGIESReproduction ensures the survival of aspecies, and nature has planned severalstrategies for it. In the case of small eggsproduced in large quantities, these areoften transparent, in an attempt to hidethem from their predators.As for large eggs, if there are only a fewtheir parents protect them most of the time.In both cases, the aim is to reduce thenumber of losses as far as possible. In anaquarium, the intervention of the fishkeeperconsiderably increases the chancesof success, and the survival and proliferationof a species is normally guaranteed.Reproduction techniques for aquariumsThese vary according to the different familiesof fishes, and they will be discussedin greater detail in the "Catalogs of Fishes"(pages 75 and 126). However, it is possibleto advance some general precepts onthe subject here.Choosing the reproduction siteReproduction can occur spontaneously ina mixed tank, or in a specialized or"regional" aquarium. This often happenswith novice aquarists, unaccustomed tospotting the approach of egg-laying in afemale. In such cases the future of the fryisa matter of chance. Some of them willserve as prey for the other inhabitants ofthe tank, and the survivors are sure tohave problems in getting enough to eat.since they have to compete with adults.This is why it is advisable to use a tankspecially intended for reproduction.Choosing the reproducing fishAlthough it is sometimes difficult, at thebest of times, to distinguish betweenmales and females, it is easy enough tospot a female's swollen stomach and theattentions bestowed on her by one or severalmales - signs of the approach of themating season.It is therefore time to transfer the fish inquestion into the rearing tank preparedfor this purpose.

REPRODUCTIONCARING FOR THE PARENTS• The selection and feeding of the parents areimportant factors in successful breeding. Here, apair of Colisa lalia, the male is on the right.Successful reproduction depends on the good healthof the reproducing fish, and to achieve this they have to remainundisturbed, and therefore isolated, in a rearing tank. Theirfeeding is especially important, as the quality of the eggs, andabove all that of the vitellin, depends on it. Fresh food, particularlylive prey, must be provided, with an emphasis on variety.Although artificial food can be used as a substitute, it mustnever constitute the basic diet.EGG-LAYINGOne encouragement for egg-laying islight, whether it is the morning sun or theaquarium's artificial lighting. Also, if youthink that your fish are taking a long timeto lay, you can change around 10% of thewater volume, and this may provide themwith the stimulus they need.Fish with free or non-adherent eggsWhen the eggs fall to the bed, they mustbe protected from the voracity of otherfish - and this can be done in a normalaquarium. There are a couple of ruses thatare useful in this situation:- divide the aquarium into two horizontalsections by means of a grille which onlylets through the eggs;- cover the bed of the aquarium withglass marbles - the eggs will slidebetween them and can easily be recov-ered by siphoningthem off.Most fish that producefree eggs donot take care ofthem, and theparent fish musttherefore beremoved from thetank to ensure that they do not devourthem. There are some species within theCyprinodontid family whose eggs can surviveoutside water, provided they are keptwithin a moist environment.There areseveral tricks forshielding the eggsfrom the voracityof their parents:the grille system(A) and glassmarbles (B).SEMI-NATURAL REPRODUCTIONSemi-natural reproduction can be carried out with those fish which normally live in groups and do not form stablepairs, such as the Characins. A group of ten can be inserted into a rearing tank adjusted to their requirements andleft to reproduce. There are then two possible scenarios:- the adult fish are removed and the aquarist looks after the fry;- the adults and the fry are left together, so hiding places must be providedfor the young - plants on the water surface, rocks, etc. The fry are notmoved until they measure 5-10 mm, when they are transferred to anothertank to grow into adults. The remaining adults can reproduce again as soonas the maturing phase has passed. The advantage of this method is its relativeease: one or several pairs are allowed to form and they can reproducewhenever they want. Leaving them with the eggs and fry allows a type ofnatural selection to come into play, whereby only the strongest and mostagile will be able to escape the predatory instincts of their parents.The semi-natural reproduction method can be used for neons(Paracheirodon innesi).63

FISHFish which lay nonadhesiveeggs deposit themon a support (above), in anatural or artificial cavity(center), or in a depressionhollowed out of the sediment(below).• The female laysher eggs on asupport which hasbeen cleanedbeforehand. Theywill beimmediatelyfertilized by themale. •64Fish with adhesive eggsFish such as theCharacins that do notlook after their offspringlay them on fine-leavedplants (like Myriophyllumand Cabomba),which you should makeavailable in the aquarium.Alternatively, it ispossible to use a webmade of Perlon wool,which is commerciallyavailable for use in filters.This provides a verygood artificial support.The parents must beremoved after the eggsare laid.Some species not only look after their eggs,but also sometimes their fry. Some, such asthe scalares, lay their eggs on a plant withhard leaves, while others, such as certainAmerican Cichlids, do so on a vertical orhorizontal rock face. An artificial layingsupport can also be provided, by using aPVC tube or plate, for example.Other Cichlids - Africans from Lake Tanganyikaor Americans, such as species ofthe Apistogramma genus - lay their eggs ina cavity or small cave, sometimes even onthe ceiling, if this is the only suitable place.In all cases where the eggs are laid on arigid support, this is generally cleaned byone of the parents before the femaledeposits the eggs that the male will go onto fertilize.The male will then defend the site againstany possible enemies, while the femaleventilates the eggs with her fins. There aresome occasions when the parents swaproles, and others when one of the twoeven separates out dead eggs, distinguishableby their opaque white color.The fry are then supervised by their parentsuntil they are independent.A In the case of Cichlids that use oral incubation,the fry can return to the shelter of the female'smouth (here Geophagus steindachneri).Mouth broodingThis reproduction technique, used in particularby the African Cichlids in LakeMalawi, ensures a noteworthy survivalrate for the eggs and fry, both in the wildand in the aquarium.The males, generally more intensely coloredthan the females, have small, brightlycolored patches on the anal fin. Thefemale lays the eggs on the bed andimmediately gathers them up in hermouth. Nearby, the male flaunts his analfin and rolls around on the spot. Thefemale then tries to grab the patches at thesame time as the male ejects his sperm,which the female inhales. The fertilizationtherefore takes place inside her mouth.The embryos develop for 1-3 weeks andduring that time the female does not eat.The swelling formed by the eggs in her"throat" is clearly visible.She moves theeggs around in hermouth in order to helpthem to hatch.The fry graduallyemerge from theirmother's mouth, butdart back inside at theslightest sign of danger,and the mothercontinues to take careof them until they canlook after themselves.This technique meansthat these fish canreproduce in a mixedtank. However, it is

REPRODUCTION• The fry can return to the shelter of the female'smouth, although this is very unusual if she issolated in a rearing aquarium.possible to remove the female delicatelyand, with great care, make her "spit out"her fry in order to raise them in anothertank separately.The bubble nestFish from the Belontiid family construct anest of bubbles under the surface of thewater, where the oxygen concentration ishigher, compensating for the low oxygenalionin their living environment. This refugealso affords the fry a certain degree of protection.The male builds the nest by taking in air atthe surface and forming bubbles that arestuck together with his saliva. Then he setsout to seduce the female, clasping her nearthe nest and fertilizing the eggs she lays,before putting them into the nest with hismouth. This operation is repeated severaltimes. The male then repulses the female,sometimes with great violence - in whichcase she must be removed from the aquariumto protect her from his aggression - andhe watches over the nest. After hatching, thefry stay inside for a few days, and then theydisperse. The male must be removed, as heis capable of eating them.LivebearersThese do not lay eggs; instead, the latterdevelop and hatch in the female's abdomen.The fry are therefore born alive and completelyformed, and they immediately startto search actively for their ownfood. This type of reproduction isfound in only a few fish families,such as the Poeciliids, so theseare sometimes considered to bemore highly evolved than otherfamilies of fish.Marine fishFew marine species reproduceregularly in aquariums. Apartfrom the clownfish and otherrelated species, any success isan exception. Scientific researchin this field still has a great dealof ground to cover. The use ofhormones, widespread in fishfarming, is proving promising,but unfortunately it is not as yetan option open to amateurs.Bubble nest built by a male Colisalalia (Belontiids) on the surface of thewater.The differentphases ofreproduction inBelontiids:construction of thebubble nest by themale (the female isin a separatecompartment), thelaying of eggs, theremoval of thefemale. •

HEALTHThe aquarist must learn how to detect signs of ill health, and above all establish good habitsas regards tank maintenance and food hygiene, in order to prevent disease. A fish can notonly fall sick, but can also be a carrier of a disease without actually being sick itself- thenit is known us a healthy carrier. The disease will appear under certain conditions or will bepassed on to its companions.THE ORIGIN OF DISEASESThe origin of a disease can be outsidethe aquarium- the introduction of a fish stressed byimportation, or by the living conditions ata retail store; it can fall sick and contaminateother fish;- the introduction of a healthy carrier ordiseased fish;- the introduction of polluted water froma natural source;- the accidental introduction of variousharmful substances, such as cigarettesmoke and aerosol fumes.Obviously, every precaution must betaken to avoid such accidents on the partof the aquarist.The origin of a disease can be inside theaquariumThis is generally due to a disruption of thegeneral balance, leading to the developmentof the diseases latent in a healthycarrier:- reduction in temperature or thermalshocks, i.e. abrupt variations - whetherincreases or decreases - brought about bya disorder in the heating system;- reduction in the oxygen levels;- excess of nitrogenous matter, due to afilter malfunction or too many fish;A small tank of glued glass is used, containing only the equipment necessary for treatment. Therefore, there are noplants, bed, or decor, except in the case of naturally shy fish, which can be furnished with a shelter made of anartificial material like PVC. Normal filtration is not required; the most that is needed is a small internal filter containingonly Perlon cotton. On the other hand, there must be substantial aeration, as this influences the oxygen levels.The temperature should be raised to 27-28°C.Ideally, the hospital aquarium should be in a quiet spot with little light, in order to enhance the healing process. Itis also possible to cover the glass sides.After it has been used, both the aquarium and its contents must be disinfected, using 4 ml of bleach for every 100liters of water, followed by stirring of the water over a period of 24 hours and then several successive rinses.66

HEALTH• Scatophagus argus, in a poor condition, withdamaged fins.- the general quality of the water;- an injury sustained in the course of afight or an overexcited mating ritual, orfrom collisions with or scrapes against thedecor;- underfeeding or a poorly balanced diet.HOW TO RECOGNIZE A SICK FISH?Diseases are not particularly easy to detect, especiallyif they do not manifest any external symptoms. However, severalindications can lead an aquarist to think that a fish is sick.These phenomena can be seen in isolation or together.- General behavior: the fish hides, is easily scared, and isstressed out.- Swimming: uncoordinated, and the fish may scrape againstthe decor or the bed.- Feeding: weight loss, refusal of food.- Breathing: the fish comes to the surface to "stock up" on air.- External symptoms: white spots, whitish marks, swelling ofone or both eyes or the whole body, bristling scales, severalwounds, etc.PREVENTIONPrevention is better than cure: this wiseold proverb is perfectly applicable to fishkeeping.Prevention entails daily observationof your fish and their environment,and this requires a certain degree ofknowledge. In the end, the best preventioncomes from maintaining a good balancein the aquarium.Diseases and their treatmentGenerally speaking, there are two types ofdiseases - infectious and non-infectious.The former are caused by microorganisms,such as bacteria, fungi, or virusescarried by the fish. The triggering factorsare well-known: stress, bad diet, decreasein temperature. Some pathogenic organismshave a mixed life cycle: one part onthe fish, one part in the water.Non-infectious diseases are not caused bypathogenic organisms, but by the environment(low-quality water, underfeeding).It is important to avoid any cocktails ofmedicines and useless or harmful overdoses.The treatment schedule mustalways be respected, even if the symptomsquickly disappear.When taking care of sick fish, it is best tofeed them moderately, but with naturalfoodstuffs. Once the illness is cured, providea varied and well-balanced diet, inorder to consolidate the healing process.The bearing of this fish (Macropodus opercularis) and its siightiyraised scales suggest a poor state of health.... AND A FISH IN GOOD HEALTH?There are two things to take into consideration: the fish'sappearance and its behavior. This requires a good knowledgeof its anatomy, biology, and ecology. A fish in good health hasbright colors and sparkling eyes. Its body is not swollen and itsscales and opercula do not stick out. It comes to eat in a normalway, in terms of both the feeding process itself and theamount it eats. It does not hide without a good reason.Bright colors and fully deployedfins are signs of good health.67

FISHThe most common diseases and theirtreatments are listed in the table on pages70-71.The stages of treatment1. Put the fish in a hospital aquarium.2. Raise the temperature to 27-28 °C.3. Stop the filtration, and maybe the proteinskimmer in salt water, while at thesame time increasing the aeration.4. Dilute the medicine as required.5. Pour the medicine little by little into theaquarium. It is best to spread this operationout over a period of at least one hour,or one day when administering coppersulfate.6. Leave it to act for the recommendedperiod.7. Empty out half the aquarium, then topup by adding water that is identical to theoriginal.8. Change 10% of the volume each day for5 days, always using an identical water.9. Repeat the treatment if necessary, followingthe steps above.10. Switch the filter on again and, whereapplicable, the protein skimmer.11. Gradually reduce the temperature toits original level. This operation must bespread over 3 days.12. Bring the aeration to its original level.In a mixed aquarium, the process obviouslybegins at point 2.THE GOLDEN RULES OF PREVENTION- Know your aquarium; regularly analyze certainparameters - nitrites, pH; have good-quality water;- Know your fish and their habits - behavior, feeding.- Avoid overpopulation.- Avoid both overfeeding and underfeeding;- Avoid any permanent stress, particularly from mixing fish thatare incompatible due to their size or behavior, or from a lack ofshelters and hiding places.- Do not introduce new fish directly into the aquarium.Knowing your fish well - theircolor and behavior -constitutes one of the mainrules for disease prevention inan aquarium. •• Powders such as copper sulfate and methyleneblue are weighed and then diluted in water to forma mother solution.MedicinesThere are a great many medicines on themarket, specifically formulated for one orseveral diseases. Constant progress isbeing made in this field, with new medicationfor marine fish also being producedin the last few years. It is important torespect the instructions regarding both thedosage and the treatment schedule.Bacterial diseases can be combated withantibiotics. However, the use of these substances,which are difficult to obtain, isnot recommended, and could lead to thecreation of resistant strains.Various chemical products can be used intreatment, provided the dosages are fullyadhered to.Firstly, and only to be used in fresh water,there is kitchen salt, which is effective incertain cases. It must be added graduallyto the water until a level of 5-10 g/liter isreached, but this dose must not beexceeded. Once the fish is cured, thewater is returned to its initial unsaltedstate, by means of successive changes of25% of the volume of the tank per day.Methylene blue is efficacious against fungi.Dissolve 1 g of powder - which can stillbe found in some pharmacies - into 1 literof water. Treat fish with 0.5-1 ml/liter ofthis solution, and eggs with 1 ml/liter.The product is then eliminatedthrough gradual changes of 25% ofthe volume of water. Methyleneblue cannot be used in sea water.Malachite green is particularlyeffective against fungi, but alsoagainst ichthyophthyriasis (whitespot disease). A solution of 1.5 gper 10 liters is prepared just before68

HEALTHTHE MOST COMMON DISEASESThere are very few aquarists who have never beenfaced with diseases associated with white spots or fungi.A The quantity required for treatment is taken fromthe bottle on the left, which can then be stored.use. and the treatment should not lastmore than 2 hours.Formol is active against external parasites.A commercially available 40% solution offormaldehyde is used, after diluting at therate of 20 ml/100 liters of water. Generallyspeaking, 15-20 minutes of treatment issufficient, but in any case it must neverexceed 30 minutes. The treatment can berepeated twice, at 48 hour intervals.(Copper sulfate is often used in sea water,but it is toxic for invertebrates and someplants. The ailing fishes must therefore betreated in a hospital aquarium if they arenot the sole occupants of the marine tank.Dissolve 16 g of the crystals into 1 liter ofwater; the treatment dose is 10 ml of thisdilution per 100 liters of water. As a precaution,the product's introduction intothe water can be spread out over one day.The dilutions of methylene blue, malachitegreen, and copper sulfate must becarried out with distilled water. All theseproducts, apart from the salt, must be keptin a cool, dark place - ideally, in therefrigerator.However, be aware of any possible dangers,especially to children, who might beattracted by the colored liquids formed bycopper sulfate and methylene blue.IchthyophthyriasisIn the former case, the infection is caused by a protozoon (unicellularanimal) which alternates its existence between the fishand the water. It is extremely contagious.This disease is particularly likely to develop when there is a dropin temperature, or after the introduction of a new fish. It istreated with commercially available products or with formol.The same conditions also apply to the "foam" caused by fungi,including the Saprolegnia. Its proliferation is enhanced by skinwounds. The treatment is carried out with commercial products,or with either methylene blue or malachite green.OodiniumThis is caused by a unicellular parasite that bears a flagellate,which allows it to move about. It alternates its existencebetween the water and the fish. This very contagious diseaseappears when a fish has been weakened, as up to then it wasa healthy carrier. It can be treated with copper sulfate or witha commercial medication.69

THE MOST COMMON DISEASESSymptomsName of diseaseor problemCauseType of waterWhite spots on the bodyand the fins (the size of apinhead, 1 mm maximum).ICHTHYOPHTHYRIASIS.Protozoon parasite,Ichthyophthirius.Fresh water.White spots, smaller thanthe above, forming a fineveil, the fins often stuck,scraping against the decor.OODINIUM.Unicellular parasite,Oodinium, equipped witha flagellate to movearound.Fresh water, but above allin sea water.Identical to the above, butwith bigger spots.CRYPTOCARYON DISEASE.Protozoon parasite,Cryptocarion.Sea water.White clumps with acotton-like appearance,foam.FOAM,SAPROLEGNIA.Fungi, includingSaprolegnia.Fresh water,rare in sea water.1 or 2 eyes abnormallyswollen.EXOPHTHALMUS.Bacteria, viruses,fungi, sometimesall together.Fresh water and sea water.Swollen abdomen,bristly fins.DROPSY.Mainlybacteria.Fresh water and sea water.Opercula sticking out,unsteady swimming, tinyflukes on the branchiae.GYRODACTYLIASIS.Parasitical fluke,Gyrodactylus.Fresh water.Gasping for airat the surface.Lack of oxygen.Defective aeration, generalbalance of the aquariumdisturbed.Fresh water and sea water.Weight loss,poor growth.Dietary problems.Underfeeding, orlack of vitamins.Fresh water and sea water.Agitation, uncoordinatedswimming, unusualbehavior.Bad maintenanceconditions.Oxygen problems, poorquality of water (especiallynitrogenous substances).Fresh water and sea water.Fry with deformedskeletons.Hereditary problem.Genetic origin(the parents).Fresh water and sea water.This Neolamprologus multifasciatushas foam on its wounds

IN AN AQUARIUMTreatmentIncrease in temperature, formol,malachite green, commercialmedication.ObservationsContagious, appears if there isany significant drop intemperature.Copper sulfate, commercialmedication.Copper sulfate, commercialmedication.Salt, malachite green ormethylene blue (except insea water: copper sulfate,commercial medication).Copper sulfate, commercialmedication.Copper sulfate, commercialmedication.Salt, copper sulfate.Increase the aeration, check andadjust the parameters of thewater.Fresh food alternated with liveprey.Increase the quantity of oxygen,cnange one third of the water,check its quality (nitrites, pH).Sometimes difficult to detect atfirst, common in sea water, contagious.It is sometimes associated withsmall bloody spots; fish can experiencebreathing difficulties.The disease's development isfavored by wounds.Sometimes difficult to treat.Contagious, sometimes difficultto treat.Not very easy to detect.Gasping for air can also be asymptom of an infectious disease.Possibility of incorporatingcommercial vitamin solutionsinto the food.The symptoms can alsocorrespond to an infectiousdisease.• Fish afflicted by white spot disease(ichthyophthyriasis). Easy to detect - the body iscovered with white spots - this disease is verycontagious.WHAT YOU MUST DOFOR A SICK FISH- Act immediately.- Administer the appropriate treatment.- Take care of the fish in ahospital/quarantine aquarium.Treatment must be given as soon asthe disease appears, i.e. when you seethe first symptoms, and you must actquickly.Treating a sick fish in a mixed aquariumis not without its risks: some substancescan have undesirable sideeffectson other species or on theplants. It is therefore preferable to usea hospital aquarium, or a quarantineaquarium.If a lot of fry are affected,there is a genetic problem- the parents, and they musttherefore be separated.It is not unusual for a few of thefry in a batch to be affected.• A fish's swollen abdomen is often the signof dropsy, a bacterial disease.

NOMENCLATURE AND DISTRIBUTIONOF AQUARIUM FISHThe inhabitants of our aquariums - fish, plants, or small invertebrates- all have individualnames. These, however, are often the subject of unresolved disputes: a single species can, infact, have several different names! Let's try and shed some light on this...Xiphophorushelleri exists in aconsiderablenumber ofvarieties: hifin,lyretail, wagtail,etc. •NAMING FISHES: THECORRECT TERMINOLOGYScientific and common names• Scientific namesThe scientific name is the only one whichis recognized internationally: it ensures auniversal means of communicationbetween workers in the field. It is given inLatin, following a tradition dating back tothe 18th century, and consists of twoparts:- the genus name, with an initial capital oruppercase letter.-the species name, without a capital.The scientific name is chosen by whoeverdiscovers the fish, but new scientificadvances may cause the name to bechanged. The old name, now of secondaryimportance, continues as a synonym. Thesechanges mostly affect the name of the genus.When the species name is not known forcertain, we use the abbreviation sp., anabbreviation of the Latin word species.• Common namesOften the origin of the common name isobscure. It may be translated from Latin,from another language, borrow a scientist'sname, or simply be invented as circumstancesdictate, often somewhatcontroversially. The absence of any strictrule gives rise to confusion; while somefish have no common name, others haveseveral. Such is the case with Gymnocorymbusternetzi, which has been variouslycalled the black tetra, the black widow,the blackamoor, and the petticoat fish, butall referring to the same fish.PRINCIPLES OF THE CLASSIFICATION OF LIVING CREATURESA genus can comprise several species sharing common characteristics. A group ofgenera related biologically and anatomically is called a family. Related families make up anorder. This gives us the following general scheme:• Barbusoligolepis.72

Where problems ariseProblems of nomenclature — commonerwith fish and plants than with invertebrates- can involve confusions betweenone species and another. Sometimes theLatin name continues to be used in the literature,among commercial dealers, andin contacts between aquarists, until thenew scientific name asserts itself. Somenewly discovered species are initially designatedby a numerical code or a provisionalname. On the other hand,sometimes the "new" species turns out tobe one already known: the result is thatone species now has two names. In thiscase it is the confusion between specieswhich gives rise to the problem. The multiplicationof breeds, varieties, and hybridshardly helps matters; scientists themselvessometimes have trouble finding their waythrough the maze, so what hope for theordinary hobbyist?In this book, we employ the scientificnames in common use today and havedeliberately omitted those too recentlycoined to win general acceptance. Youwill also find Latin synonyms, and namesof breeds and varieties.BREEDS, STRAINS, ANDVARIETIESIn the natural world, local breeds andstrains exist, often differentiated by color.In addition, breeders try to evolve newcolors and shapes by crossing. In bothinstances these varieties are denoted byadding epithets to the original scientific orcommon name. So we speak of the marbleangelfish, the smokey angelfish, andthe veiltail angelfish; or the veiltail swordtail,lyretail swordtail, or Berlin swordtail.NOMENCLATURE AND DISTRIBUTION OF AQUARIUM FISHCROSSES AND HYBRIDSDifferent species - usually, but not necessarily,belonging to the same genus — canbe crossed; this rarely happens in thewild, but is a technique in common useamong aquarists. Crossbreeding, if successful,produces a hybrid combining thecharacteristics of both parents. This hybridwill not receive a special name, but willbe known by the joint names of the twoparents, separated by the sign "x," whichsimply indicates crossbreeding: Fish 1 xFish 2. If the hybrid does not prove sterile,it can interbreed in its turn, either withanother hybrid or with a purebred. Afterseveral generations, it is hard to tellexactly what you are dealing with! This istrue of certain species of plants and fishfound in the aquarium trade: the Latinname is frequently unreliable, and theplant or fish will have moved on a longway from the original, recognized speciesand exhibit different characteristics.WHERE DO AQUARIUM FISHCOME FROM?Feral and captive-bred fishToday's hobbyist is unlikely to comeacross more than 300-500 of the 1,500 socalledaquarium species. Formerly, thesewent under the name of tropical fish, asthey were caught in their natural habitatsin tropical areas all over the world (seemap on following page). Nowadays,80-85% of freshwater species are bred incaptivity, and by no means always in theirnative regions, so the term "tropical" is nolonger appropriate.The dominant output is from South-EastAsia, shared between Hong Kong, thePhilippines and Singapore, accounting forover three-quarters of species. The neontetra. for instance, originally from SouthAmerica, is bred at the rate ofthousands per month.Other areas of the world producea limited range ofspecies; some, like theformer Czechoslo-Parrot cichlid: across betweenCichlasomalabiatum andHeros labiatus.73

FISHOUTLINE DISTRIBUTION OF TROPICAL FISHvakia, are beginning to breed on a largescale. Breeders either use imported juvenilesor raise their own stock, thus reducingthe number of catches made from thewild and helping to preserve the naturalfauna. All the same, some species nolonger exist in their former abundance -for example in the Amazon basin - andproposals are afoot to declare certainareas protected zones to safeguard localpopulations.As for marine fish, almost all species arecaught in the wild. Aquarists are frequentlyaccused of abetting the plunderingof coral reefs; the argument is that, forevery fish arriving in our aquariums, ninedie at the time of capture, during transport,or at various stages of handling.Without precise studies, it is extremely dif-ficult to know the real effects on the naturalenvironment of catches that are madeto supply aquariums.Harvesting of tropical marine fishThere was a time when any method ofcatching fish was considered legitimate:explosives or cyanide were used to stunthem, for example, inflicting severe losseson their populations. At the presentmoment, the genuinely professional firmsemploy more sophisticated and humanemethods: a team of several divers worksaround a section of reef after sealing it offwith a net. After selecting fish according tovarious criteria (especially size) and catchingthem in hand nets, they carefully bringthem to the surface and house them inholding tanks to await export.Catching tropicalfish with a net. •Protected speciesHobbyists do not keep protected species;it is therefore unfair to blame them for thereduction in numbers or disappearance ofthese fish from the wild. Most aquariumspecies exist in large numbers in Nature;some even provide a food source for thelocal human population.74

FRESHWATER FISHThese inhabit various biotopes in tropical and equatorial regions.Basically they may be divided into two groups.The first comprises those for which soft, acidic conditions are essential.Some require a very low level of hardness, with a typical pH of around6. The second group prefers hard, alkaline conditions. For some speciesthe level of hardness must be extremely high, with a pH of up to 8. A fewspecies can survive in brackish water.There are some fish which are not dependent on water quality. Theseare consequently ideal for the beginner, who can, in principle, fill theaquarium from the household supply.Though there are over 10,000 species native to inland waters,only a few hundred need concern the aquarist.

FRESHWATER FISHCHARACIDAE (CHARACINS)The majority of characidae commonly known asCharacins (over 1,000 species in all) live inSouth America, especially in the Amazon basin, butnot all are aquarium fish. You can usually identifythem by a small adipose fin situated between thedorsal and caudal fins; however, this is not alwayspresent, and is also found in certain catfish species.Their solid teeth indicate that they are carnivores:their diet consists, among other things, of insectsand insect larvae.Characins live in groups or shoals in running waterand pools where there is plentiful shade and vegetation,factors which guarantee the protection oftheir eggs. Gregarious and peaceful, they can bekept in community tanks of no great size, providedthe water is soft and acidic; this requirement appliesparticularly to the black water Amazonian species,such as neon tetra, cardinal tetra, glowlight tetra.and black tetra.There must be abundant plant life in the tank inorder to diffuse the light. The Characins will acceptmanufactured food, but they are voraciously fondof small, live prey. Getting them to spawn, onceconsidered a problem, is within the scope of thehobbyist with some experience: most species reproduceindeed in the same manner. The aquariumshould be small - 50 liters or less - and you needto use marbles, peat, or fine-leafed plants to protectthe eggs. The water must be soft and acidic, and thelight levels low: the aquarium can even be placedin total darkness. Remove the breeding pair (or alladults if you have used two males to onefemale) after mating, or they willdevour their own eggs. The fry -which grow rapidly - will takesmall, live prey just a few days afterhatching; you can then restore thenormal lighting.Anoptichthys jordaniAs a result of geological upheavals, the blind cave tetrafound itself trapped in a number of subterranean rivers inMexico. Over the course of time it lost the use of its eyes,but it can still find its food on the riverbed, thanks to itssense of smell. The sensory organs of its lateral line allow itto avoid obstacles, even unanticipated ones, such as thehuman hand. Size: 8-10 cm.Cheirodon axelrodiThe cardinal tetra needs peatfiltered,acidic water to bring outthe best in its coloration. Forbreeding, water hardness must bepractically zero; pH can be as low as6. The development of the eggs(300-500 approximately) must takeplace in darkness. Size: 4-5 cm.AphyocharaxanisitsiThe bloodfin is a freeswimmer living inshoals and requiringuncrowded conditions.It will eat dried food, butprefers small, live prey.Size: 4-5 cm. •Gymnocorymbus ternetziThe black tetra or black widowbreeds best in low light levels andcan lay up to 1,000 eggs in soft,acidic conditions. A veil variety,with noticeably larger fins, hasbeen evolved through artificialselection. Size: 5-6 cm.THE EXCEPTIONPhenacogrammus interruptus (theCongo or Zaire tetra) does notshare the same origins as otherCharacins. It lives in shoals in soft,mildly acidic conditions, and needsplenty of swimming space. The male isrecognizable by the tubercleon the middle of the anal fin.Size: 10-13 cm.76

CHARACIDAE• Hemigrammus bleheriThe rummy-nose tetra prefers brown water.Often confused with related species H.rhodostomus (red-nose tetra) and Petitellageorgiae (false rummy-nose), butdistinguished from them by the extensionof the red coloration to the beginning ofthe lateral line. Size: 5 cm.Hemigrammus caudovittatusSomewhat shy at first, the Buenos Aires tetra nonethelessacclimatizes easily, especially within a shoal of ten or soindividuals. The female can lay up to 1,000 eggs. Size: 8-10 cm.• HemigrammuspulcherThe garnet tetradelights insmall, live prey. Breeding is consideredproblematic: pH 6.5, hardness 0-1.12%GH10-20 ppm), low lighting. Size: 4-5 cm.Hemigrammus hyanuaryThe January tetra is still fairly rare incommercial outlets. It thrives on regularwater changes and moderate light levels.Size: 4-5 cm.Hemigrammus erythrozonusThe glowlight tetra will spawn under dim lighting, in soft, acidicwater (pH: 6.5). Use peat filtration. A shoal of ten or so of thesevery tranquil fish produces a stunning effect in a South Americantypetank. Size: 4-5 cm.Hasemania nanaThe silver-tipped tetra can bedistinguished from other Characins by theabsence of an adipose fin. It lives in shoalsin acidic, densely planted conditions. Size:4-5 cm.77

FRESHWATER FISH• Hyphessobrycon callistusThe callistus or jewel tetra is frequently confused with H. serpae(serpae tetra) and H. bentosi (rosy tetra). It likes clear, wellplantedwater. Spawns prolifically under moderate lighting in soft,acidic conditions. Size: 4-5 cm.• Hyphessobrycon peruvianusThe Loreto tetra, little commercialized, remains relativelyunknown. It thrives and breeds best in shady, peat-filtered water.Size: 4-5 cm.CHARACINS FOR THE BEGINNERBreeding from this family is not always somethingfor the beginner, though day-to-day careis not particularly difficult. We suggest the novice try twospecies:Hemigrammus ocelliferThe head- and tail-light fish is one of the commonestcharacins, and also one of the least fussy about waterquality for breeding. In general, males have asmall, elongated white spot on the analfin. Size: 4-5 cm.HyphessobryconbentosiThe absence of a black spotbehind the head distinguishesthe rosy tetra from H. callistus:the callistus or jewel tetraThe male's dorsal fin is tallerthan the female's. Afterspawning, the eggs sink to thebottom, and the parent fishmust be prevented from eatingthem. Size: 4-5 cm.HyphessobryconherbertaxelrodiThe black neon tetra likesclear, acidic water, andsometimes seeks out shadedareas. It will breed at 26°C invery soft water; the eggs needvery dim light to hatch. Size:4-5 cm.78Hyphessobrycon pulchripinnisThe lemon tetralives in a shoalamong vegetation.The eggs are laid in thefoliage of particular plants.Size: 4-5 cm.HyphessobryconerythrostigmaThe dorsal fin of the bleedingheart tetra is more elongatedthan the female's. Breeding isdifficult and requires peatfiltration, with fine-leafed plantsfor a "spawning substrate."Incubation must take place indarkness. Size: 4-5 cm. •

CHARACIDAENematobryconpalmeriThe emperor tetra swims insmall shoals, sometimes hidingin the vegetation. The males,more brightly colored than thefemales, can be mutuallyaggressive. This is not a prolificspecies, and breeding isawkward. Size: 5-6 cm.• Paracheirodon innesiThe coloration of the neon tetra, set off to perfection by darkwater, has earned it both its name and tremendous popularity.Breeding requires good water quality with peat filtration: pH closeto 6, hardness level approaching 0. Size: 4-5 cm.• Prionobrama filigeraThe glass bloodfin is a topfeederwhich hangs around thefilter outlet. It can also leap outof the water. Does not requiresuch soft or acidic conditions asother Characins. Size: 5-6 cm.Moenkhausia sanctaefilomenae •The yellow-banded Moenkhausia prefers still water, swimmingin shoals among the vegetation. Breeding is awkward, anddemands diffused light and very soft water. Size: 5 cm.MegalamphodusmegalopterusThe black phantom tetralives in shoals, in acidic, clearwater, and needs plenty ofswimming space. Breeding isdifficult: use diffused lighting,and peat filtration giving a pHof 6. Under these conditions,the female, recognized by hershorter dorsal fin, can lay up to300 eggs. Size: 4-5 cm. •79

FRESHWATER FISHThayeria boehlkeiBoehlke's penguin swims obliquely, head uppermost. It prefersdark water and diffused light. Breeding is uncomplicated; thefemale lays around 1,000 eggs. Size: 4-5 cm.Pristella maxillarisThe X-ray fish is robust, quite tolerant of water quality, but hardto breed. Size: 7 cm.FAMILIES RELATED TO THE CHARACIDAELebiasinidae - Gasteropelecidae - Serrasalmidae - AnostomidaeAfew fish with certain anatomical resemblances to Characidae are found in hobbyists' tanks. In thewild they are native to South America, living in soft, acidic waters.The Lebiasinidae (pencilfish) are top-dwellers and can leap out of the water. The high position of themouth indicates that they catch small prey near the surface.The Gasteropelecidae (hatchetfish) owe their name to the shape of their bodies. Their rectilinear backsand slightly upturned mouths denote that they too are surface-feeders; they also share the pencilfish'sacrobatic ability. They flourish in calm, shady conditions.The family Serrasalmidae includes piranhas, whose behavior and aggressiveness are well known, butalso exaggerated; they are only dangerous in the presence of blood, the scent of which drives them intoa frenzy. They are voracious carnivores favoring a meat-based diet.Metynnis belong to the same family as the piranhas and resemble them. However, theyare inoffensive, and their diet is predominantly herbivorous.Anostomidae are somewhat aggressive. In their natural habitat, their streamlined bodiesand transverse or longitudinal stripes serves a camouflage, blending them in with thevegetation.Leporinus striatus(Anostomidae)The striped leporinus is anomnivorous species, but requires extravegetable material. Its size andaggressiveness require it to be kept ina large, covered tank, as it is capableof leaping out of the water. Size:20-25 cm. •80

CHARACIDAE: RELATED SPECIESMetynnis argenteus(Serrasalmidae)The silver dollar closelyresembles the piranha,but it is herbivorous,needing largesupplements ofvegetable material;without these, it willnibble away thevegetation. Size:10-15 cm.• Carnegiella strigata(Gasteropelecidae)The marbled hatchetfish lives in small shoalsand is a surface-feeder. It shows a preferencefor live prey, but will not refuse commercialfoods. Size: 5 cm.Nannostomus trifasciatus (Lebiasinidae)The three-lined pencilfish requires shady vegetation butalso swimming space. Though the female lays prolifically(around 1,000 eggs), hatching and rearing are traditionallyconsidered difficult. Size: 5-6 cm. •• Serrasalmus nattereri (Serrasalmidae)This is the red-bellied piranha. In captivity, piranhas must beisolated from other species in a spacious, well-planted tank.They are by preference carnivorous: feed meat, mussels, orsmall, live fish. Reproduction is difficult in captivity.Size: 20-30 cm.Gasteropelecus sternicla(Gasteropelecidae)The silver hatchetfish issomewhat larger andmore timid than C.strigata, but shares itsreluctance to breed incaptivity. Size: 5-6 cm. •Nannobrycon eques(Lebiasinidae)The hockey-stick pencilfishor brown-tailed pencilfishswims at an angle of 45°,head upwards. Fairly timid, itlives in shoals, and is oftensomewhat awkward to breedSize: 5 cm.81

FRESHWATER FISHCYPRINIDAEWidely distributed over the planet theCyprinidae (barbs, danios, rasboras, labeos,carp, etc.) form one of the largest freshwater families,with more than 2,000 species. The smallestspecies - only a few centimeters in length - arevery well known and extremely popular with hobbyists.The largest, which can grow up to 1 m inlength, constitute an important human food source:the annual captive production of various types ofcarp - the most familiar member of this family -exceeds 6 million tonnes, and if we lump togetherall species (including freshwater and marine aquaculture)we end up with a figure of around 17 milliontonnes.The Cyprinidae are characterized by a frequentlythick-set body and rather broad scales; most surprisingly,the teeth do not grow from the jaw butare relegated to the throat. These fish originate fromquite diversified biotopes, but acclimatize to thedomestic aquarium without difficulty. They areomnivores, and some species detect their food bymeans of their barbels.A Barbus oligolepisThe checker barb is a gregarious species. Spawning (relativelyuncomplicated) demands slightly acidic conditions andfine-leafed plants. It is easy to cross with otherbarbs. Size: 5 cm.Barbus schwanenfeldiThe tinfoil barb or Schwanenfeld'sbarb can exceed 25 cm in theaquarium. More or less peaceful,it does however require plentyof space, with abundantfood, includingsupplements of vegetablematerial. Size: 25-30 cm.BarbsBarbs are native to Asia and Africa, living in shallow,moderately fast-flowing waters rich in vegetation;among the hundred-odd known species inNature, only a dozen or so are currently availablecommercially under this collective name. The differentspecies can be distinguished by the numberof barbels, which varies from none to four. Theyare active fish, living in groups or small shoals, andthe liveliest ones may even tease other species withquite large fins. They are best kept in aquariumswith plenty of plants and where the water is soft,slightly acidic, and well-filtered and oxygenated.Barbs are omnivorous (taking small, live prey orvegetable material) and adapt well incaptivity to artificial foods. Spawning(reasonably straightforward) requiressoft, mature water; the optimal temperatureis usually around 28°C. Afterhatching, the fry measure just over 3mm; food when they are at this stageshould be Artemia nauplii.CROSSBREEDINGBARBS FOR THE BEGINNERThe rosy barb (Puntius conchonius)is very gregarious.It breeds easily (the male taking on apink coloration) in soft, seasoned water.The eggs - sometimes over 100 in number- adhere to plants and other supports;the parent fish must be removed after laying.Hatching takes place after 36 hours. For the first 2days after they are free-swimming, feed the fry oninfusoria. Enthusiasts have evolved a veil variety by selective breeding. Size: 8 cm.Some species of barbs can becrossed to produce viable fry, as withPuntius nigrofasciatus (black rubybarb) and Capoeta tetrazona (tigerbarb), a hybrid of which is shownhere. Size: 5-6 cm.82

CYPRINIDAECapoetasemifasciolatusThe green barb orhalf-striped barb isperhaps the speciesresponsible for theproduction, bymutation orhybridization, of thegolden barb - see C.schuberti The maleis more elongateand brightly coloredthan the female.Size: 8-10 cm. •• Capoeta titteyaThe cherry barb is one of the smallest members of thisfamily. It owes its common name to its color, which, inthe male, deepens noticeably at mating time. It is quitetimid, preferring shaded areas. The female can produceseveral hundred eggs. Size: 5 cm.• Capoeta schubertiThe golden barb is acuriosity: unknown in thewild, it is most likely amutation or a hybrid ofrelated species. It isgregarious, swimmingactively in groups.Breeding is quite easy; theeggs hatch in 36 hours inWater at 26°C. The frygrow quickly and maturewithin 10-12 months.Size: 5-6 cm.• Capoeta tetrazonaGolden tiger variety.Size: 5-6 cm.Capoeta tetrazonaThe tiger barb is one of themost common species. Duringmating, the males becomemarkedly aggressive towardsthe females. The stripes appearon the fry within 2 weeks orso. There are several varietiesof this species: the green tiger,the albino tiger, and thegolden tiger (without the blackpigmentation).Size: 5-6 cm.• Banded barbs Certain species have "stripes", mainly in the form of transverse bands; their size and number serveas a means of identification. Size: 5-7 cm.Capoeta tetrazona(tiger barb)Barbodes pentazona(five-banded barb)Barbodes everetti(clown barb)Puntius lateristrigata(T-barb or spanner barb)Puntius nigrofasciatus(black ruby barb)83

FRESHWATER FISHDaniosHardy, continuously active, easy breeders, unfussyeaters, danios have the ideal qualities for a starterfish. Like barbs, they are extremely gregarious.Danio aequipinnatusLarger than its cousins, the giantdanio is just as hardy and easy tospawn. Size: 8 cm.SPAWNING THE ZEBRA DANIOYou can breed the zebra danio in a tank without substrateusing a mixture of new water with some taken from theparents' aquarium. The hardness level must be low, pHneutral, and the optimum temperature is around 26-27°C.To prevent the parent fish devouring the eggs, which theywill do with gusto, keep the depth of water between 10and 15 cm. The eggs will then sink quickly: a layer of marblesprepositioned on the bed will provide safe lodgingplaces. Alternatively, suspend a layer of fine netting halfwaydown, allowing the eggs through but not the parent fish.For a set-up like this, use two males to one female, choosinga female with a plump belly, indicating that she is ripe.After laying - which seems to be stimulated by the first raysof the morning sun - remove the parent fish. Incubation ofthe eggs (up to 200 or 300) lasts 2-3 days, with the fryswimming between the 6th and 7th days. It is vital to feedthem small, live prey - infusoria or rotifers if you can getthem.A DANIO FOR THE BEGINNERKnown, raised and bred in Europe since theearly 1800s, the striped or zebra danio(Brachydanio rerio) has given countless hobbyists theirfirst real thrill of excitement. Twenty years or so ago, a veilform appeared, though, curiously, this fish has not givenrise to other selective forms. Its hardiness and its readinessto spawn have been put to use by scientists to test the toxicityof certain substances. Recently they managed to producea line of clones: genetically identical fish, and thereforewith the same reactions to a given phenomenon, thus eradicatingthe influence of genetic variability on experiments.Size: 5-6 cm.• Brachydanio frankeiThis species, which resembles atiny trout, appears not to existin the wild, possibly derivingfrom isolated laboratory stock.The fish currently soldcommercially originate fromlocalized breeding centers inSouth-East Asia. The leoparddanio, as it is commonlyknown, lives in shoals near thesurface and acclimatizes easily.A veil form exists, withmarkedly elongated fins. Size:5-6 cm.BrachydanioalbolineatusThe pearl danio is a shoalswimming,voracious feeder. Itcan survive temperatures below20°C. Size: 6 cm. •84

RasborasThese small, lively fish live in groups or shoals infast-flowing, shallow water, their forked fins clearindicators of their swimming ability. A robustspecies; they are easy to care for in soft, slightlyacidic conditions, but breeding is a less straightforwardproposition.CYPRINIDAERasbora borapetensisThe magnificent rasbora or red-tailed rasbora will spawn (upto 500 eggs) in a small, darkened tank containing fine-leafedplants. The fry must be fed with small, live prey for 2 weeks.Size: 5 cm.A Rasbora heteromorphaThe harlequin rasbora is one of the most popular species of thisgroup. It spawns in acidic conditions (pH 6, with peat filtration),ideally in a darkened tank, sticking its eggs on or underneath largeleaves. Size: 5 cm.Rasbora elegansThe elegant rasbora lives nearthe surface of open water, andrequires plenty of swimming spacein captivity. To set off its colorationto perfection, use a dark bed.Keep the water acidic and slightlyhard. Size: 5 cm.THEBEGINNER'SRASBORAThe scissortail (Rasbora trilineata)owes its name to itstail movements and needsplenty of room.The eggs, only slightly adhesive,are laid in the finefoliage of certain plants,hatching in 24 hours.It accepts both artificial foodsand live prey. Size: 10 cm.85

FRESHWATER FISHLabeosOne look at the labeos' shape reveals that they are bottom-dwellers in fast- flowing water: quite streamlinedto minimize current drag, with a flat belly for resting on the bed and barbels for sensing prey on orin the substrate. These fish are primarily "twilight" (nocturnal) species; they are also aggressive toward conspecificsin defense of their territory, though coexisting peacefully with other species.As is the case with other aquarium fish, it has become possible to breed the labeo borrowing techniquesrecently developed by scientists for propagating marine species. This involves the use of hormones, andis a method unavailable to the amateur breeder.What happens is that the hypophysis - a small gland located at the base of the brain - is removed fromcarps or related species and crushed in a slightly saline solution. A minute quantity of this solution - containingthe diluted hormone - is injected into the chosen fish; if she is "ripe," she will start to lay within24 hours, producing hundreds of eggs.Labeo frenatus •Albino variety.Size: 10-15 cm.Labeo frenatusThe red-finned shark or rainbow sharkis distinguished from Labeo bicolor by a less intensebody coloration and by its redfins. Sometimes a commercialalbino variety is found, which canbe mated with the normal variety;the fry will then display the colorationof one or other of the parents.Size: 10-15 cm.Labeo bicolorThe red-tailed black shark, rather nocturnalin its habits, obtains its food by sifting the bedof its natural habitat. In captivity, it needsextra vegetable material. By day it lurks invarious hiding places (rocks, roots, etc.) whichform an essential part of the aquariumfurnishings. Size: 10-15 cm.The goldfish: theme and variationsThe goldfish is the oldest "domesticated" fish; itsstory began long before hobbyists started keeping itin aquariums. The feral form, less brightly coloredthan the present fancy varieties, can reach 40-50 cm.Originating from Asia, it has now spread throughoutall the temperate waters (5-25°C) of the globe. Theclassic red variety was selectively bred from feralstock, probably before the time of Christ, thoughbreeding has made enormous advances since theMiddle Ages. The earliest importations to Europedate from the 17th century, in the form of gifts madeto the French royal family. There are many varieties,all of which have been isolated, after a long andpainstaking series of selections, using the familiarred strain as a starting-point.86Goldfish varieties (Carp family)

ShubukinThe dorsal and caudal finsare markedly elongate.Coloration: variegated,with no fixed pattern.Size: 10-15 cm.CYPRINIDAEJapanese veiltailThe veiltail has a caudal fin composed oftwo or three lobes. Size: 10 cm. •Though people often confuse koiwith goldfish, these are in fact differentvarieties of carp selected (startingfrom the feral variety) over more than1,000 years. They can reach 1 m inlength, and the presence of barbelsclearly distinguishes them from thesmaller goldfish. Size: 20-50 cm.CARING FOR GOLDFISHTelescope-eyed goldfishThe eyes of this variety are globular andprotruding; sometimes the dorsal fin isabsent. The commonest varieties areentirely black. A close relative is thecelestial goldfish. Size: 10 cm.Goldfish must be kept in conditionscorresponding to their natural habitat;the aquarium must be bigenough to let them swim freelyamong the plants, while the substratecan be fairly coarse. Filter thewater, but do not use heating: goldfishare considered hardy, but themaximum temperature should be20-22°C, while below 5°C the fishbecome noticeably sluggish. Hardnessand pH are not so critical as withother species of aquarium fish.The bubble-eyeYou can spot this variety at once by the bubblelikepocket under the eyes. The caudal fin maybe normal, or divided into several lobes. Othervarieties of goldfish exist; in addition, there is muchcrossbreeding between those mentioned here. Inevery case, color may be uniform or appear as red,yellow, gold, white or black splashes. Size: 10 cm.LionheadThe lionhead has protuberances inthe form of swellings on top of thehead. Sometimes there is no dorsalfin. Size: 10 cm.THE GOLDFISH (CARASSIUS AURATUS):A ROARING COMMERCIAL SUCCESSBreeding goldfish, which are unlikely to go out of fashion, is an important commercialactivity. Besides its popularity with hobbyists, it is used as live bait - understringent legal conditions - for the capture of carnivores. The modern varieties areraised in Italy, though the most sophisticated forms (often called "Chinese") areproduced in Asia.A GOLDFISH HILTONIf you want to offer your goldfish thevery best conditions, keep them in agarden pool where they will growmuch larger; they will overwintersafely, even if the water partiallyfreezes. Breeding is by no meansimpossible outdoors, provided theminimum pool temperature is19-20°C. However, the parents willtry to gobble the eggs. The fryacquire the characteristic colorationonly after several weeks.87

FRESHWATER FISHOther Cyprinidae: Balantiocheilus -Epalzeorhynchus - TanichthysAs well as the groups already mentioned, which arcthose most commonly obtainable from commercialoutlets, there are a few other species of interest to theamateur aquarist.Epalzeorhynchus kallopterusTranquil enough - even timid - except with its own species, the flyingfox is a bottom-feeder. It has not yet been successfully bred in theaquarium. A closely related species, E. siamensis or Siamese flyingfox, has the reputation of keeping down green algae which cansometimes proliferate; it is distinguishable from E. kallopterus by thelongitudinal black band running along the middle of the body only asfar as the caudal fin. Size: 10-15 cm.• Tanichthys albonubesThe common name of this small fish is the white cloudmountain minnow. Beginners will find it worth trying forits sturdy constitution: it can withstand temperatures as lowas 18°C. It is also simple to breed from, as the parents donot eat the eggs. Size: 5 cm.Balantiocheilus melanopterusYou will need a large tank for the bala or tricolorshark, which revels in swimming and can leap out ofthe water. There is no evidence that it has beensuccessfully bred in the aquarium. Size: 20-30 cm. •COBITIDAEThe Cobitidae are close relatives of the Cyprinidae and are found in both Europe and Asia. They possessa small number of barbels which they use to detect prey as they search the substrate. Given thisfeeding procedure, it is preferable to use a fairly fine, smooth sand. You can recognize these fish by thepresence of a spine under the eye; this is designed for defense, but can also entangle the fish in the handnet. Loaches, as they are commonlyknown, are bottom-dwellers, and basicallytwilight species; they hide away during theday, so you will need to provide lurkingplaces. They are happy with artificial food,but will not spawn in the aquarium.Acanthophthalmus kuhliThe coolie loach. A number of species are availablecommercially under this name; they differ only in thepattern of their coloration. Shy and non-aggressive,they can leap through any tiny gap in the aquarium lid.They have been successfully bred with the aid ofhormones, like the labeos; otherwise they rarelyreproduce in captivity. Size: 12cm •88

COBITIDAEBotia macracanthaThe clown loach is the most well-known and commerciallysuccessful species of the genus Botia. All species are bottomsifters,i.e., they search the substrate for food. None will breed incaptivity. A twilight fish, mainly hiding away during the daytime,the clown loach can be aggressive when cramped for space ordefending territory. Size: 15 cm. T• Botia lohachataThe Pakistani loach is less nocturnal than its relatives, and willnot hide away when the aquarium is illuminated. Size: 10 cm.Botia modestaThe orange-finnedloach takes its namefrom the more orless pronouncedreddish-orangecoloration of the fins. Lesscommon than other membersof the genus. Size: 15 cm. •AcanthopsischoirorhynchusThe horse-faced loach or long-nosed loach is anothertwilight species, burying itself in the sand during daylight,with only its head showing. Size: 15 cm.• Botia horaeHora's loach changes coloraccording to its moods, sometimesdisplaying pale banding. Rathermore active than related speciesSize: 10-12 cm.Botia striataOne of the prettiest of the loaches, the zebra loach hasthin transverse bands along its body. Size: 10 cm.• The four main species of AcanthophthalmusA. kuhli kuhli A. kuhli sumatranus A. myersi (slimy myersi) A. semincintus (half-banded loach)89

FRESHWATER FISHCATFISHCatfish belong to different families, but are all members of the order Siluriformes. They possess barbels,live a solitary life on the bottom, and are mainly twilight species. Not very fussy about waterquality, they play a major part in maintaining the balance of the aquarium as they scavenge algae or particleswhich have sunk to the bottom.Two families are of particular importance: the Callichthyidae and the Loricariidae. The Callichthyidaeinclude the genus Corydoras; these fish do not have scales, but their flanks are covered in layers of overlapping"shingles" (bony plates) They can also be recognized by the barbels round their mouths and thespines on their dorsal and pectoral fins. Their flat bellies indicate that they live and search for food (artificial,or small live prey) on the bottom; they are active mostly at dusk and during the night. Originallynative to South America, Corydoras species are ideal subjects for keeping in a regional aquarium alongwith Characins, angelfish or discus. Ten or so species are currently available in the trade; others appearon the market intermittently.The Loricariidae live on the beds of streams and rivers in South America. Their mouths resemble suckers,their bodies are "armor-plated," and they often have spines on their fins. All are either partially orcompletely herbivorous. It is very rare to hear of them breeding in captivity.Corydoras arcuatus(Callichthyidae)The skunk catfish. The Latin arcuatus(banded) refers to the broad black bandrunning along the back from the eye to thecaudal peduncle. Generally considered adifficult subject; this includes breeding.Size: 5 cm. •Corydoras trinileatus(Callichthyidae)The arrangement of spots on the three-linecorydoras varies according to its origins.Prefers diffused illumination. Harder tobreed than the peppered cory. Size: 5 cm. •Corydoras melanistus(Callichthyidae)The black-sail corydoras orblack-spotted corydoras has adistinctive black smudge near thedorsal fin. The female lays100-200 eggs which hatch in aweek or so. Size: 5 cm. TCorydoraspunctatus(Callichthyidae)In color, the spottedcatfish resembles theskunk clownfish, withwhich it is oftenconfused, but the blackmarkings on the back areabsent. Size: 5 cm. •C schwartziC. schwartzi(Surinam sub-species)C. melanistus C. melanistus(sub-species)90

CATFISHCORYDORAS SPECIES FOR THE BEGINNERTwo robust and sturdy species are particularly recommendedto the beginner.The aeneus catfish or bronze catfish(Corydoras aeneus) is rather drab: there isalso an albino variety created throughartificial selection. As with manyCorydoras species, the male's dorsaland pectoral fins are more pointedthan the female's.The peppered corydoras (C. paleatus) has long been familiarto aquarists, and is raised in South-East Asia. The femalelays 50 eggs a day, sticking them to a suitablesurface, even the walls of the aquarium;she may continue laying like thisfor several weeks. Size: 5 cm.Corydoras aeneusCorydoras paleatusCorydoras aeneusAlbino variety. •Corydoras metae (Callichthyidae)The female of the bandit catfish fastidiously cleansplants or the glass of the tank before sticking hereggs to them. Size: 5 cm. •• Corydoras julii (Callichthyidae)One of the most attractive Corydoras species is the leopardcatfish, so known because of its distinctive spot pattern. Rathershy, and difficult to breed, it is easily confused with species havingsimilar markings. Size: 5 cm.• Corydoras schwartzi (Callichthyidae)Schwartz's corydoras is often confused with other species: its colorationvaries according to region. Given that there are over 150 feral species ofCorydoras, it is not hard to see how confusions arise in distinguishing betweenfish species. Size: 5 cm.BREEDING CORYDORASOnce considered extremely difficult, this is now within the scope of the experiencedand meticulous hobbyist. There is a boisterous-mating display, with the malechasing the female for perhaps several days. Spawning may be triggered by a variationin atmospheric pressure, a water change, or a rise in temperature. The malestations himself near the female, sometimes hanging perpendicularly in the water,to ensure his milt thoroughly fertilizes the tiny eggs. The female takes the eggsbetween her ventral fins and deposits them on a suitable surface which she haspreviously meticulously cleaned. The pair may repeat this ritual several times andhatching takes place a few days later. Note that the fry are very sensitive to anychanges in their environment.91

FRESHWATER FISHHypostomus plecostomus(Loricariidae)The pleco feeds on algae, spending thenight on the bottom. Once it has reached acertain size, it can become invasive anddisturb the decor, so it needs a roomytank. Size: 20 cm.• Ancistrus sp.(Loricariidae)Several species ofthe bristlenose aresold in commercialoutlets under aconfusing variety ofnames. Maturemales can bedistinguished by thepresence of longbarbels on the head.Ancistrus browsesencrustant algae. The femaledeposits her eggs on carefully selected sites, thoughcaptive breeding is rare. Size: 13 cm.Farlowella sp. (Loricariidae)The mouth of the twig catfish ispositioned well back underneath the head.This is a nocturnal bottom-dweller, notknown to spawn in captivity. Size: 15 cm.A LITTLE SCAVENGER FORTHE BEGINNER: OTOCINCLUSVITTATUS (LORICARIIDAE)This is a small, peaceable fish that lives on adiet of algae. It very rarely spawns in captivity.Size: 5 cm.Gyrinocheilusaymonieri(Gyrinocheilidae)The Chinese algaeeaterhas a sucker-likemouth for grazingalgae. As this fish grows,it can become aggressive.It clings to rocks, foliage orthe glass. Size: 1 5-20 cm. •• Acanthodoras spinossimus(Doradidae)The talking catfish has spines along itspectoral fins. It prefers darkness and soft,acidic conditions. It is omnivorous andquite shy. Size: 12 cm.Sorubim lima (Pimelodidae)The peaceable shovel-nose catfish can reach 60 cmin length; a spacious aquarium is therefore essential.Mainly nocturnal; it is a greedy feeder, taking live preyor fresh food. There is a serrated spine on eachpectoral fin. •92

Synodontisnigriventris(Mochokidae)The adult of theblack-belliedupside-downcatfish swims, asthe name suggests,belly upwards,while juvenilesbehave quitenormally. Anocturnal,peaceable species,it is omnivorous,but will require asmall amount ofextra vegetablematerial. Rarelybreeds in captivity.Size: 10cm.CATFISH• Kryptopterus bicirrhis(Siluridae)The glass catfish or ghost catfish, one ofthe few aquarium species with atransparent body, has two long barbelsacting as organs of touch. In the wild itlives - and breeds - in shoals in openwater. It is not suitable for mixing withboisterous species, and will not spawn inthe aquarium. Size: 10-12 cm.• Synodontispetricola (Mochokidae)Like S. nigriventris, the evenspottedsynodontis is a nativeof Africa. It swims in a normalposition and often remainshidden during the day. A fewother species of Synodontisare available commercially.Size: 10 cm.• Pimelodus pictus(Pimelodidae)A twilight species,somewhat solitary,the angelicuspimelodus lives onthe bottom andrequires plenty ofswimming space. Asyet it has not beensuccessfully bred incaptivity. Size: 15 cm.• Eutropiellus debauwi(Schilbidae)A good swimmer, the three-stripedglass catfish lives in shoals, frequentlyhanging in an oblique position, and islikely to die if kept in isolation for long.Omnivorous, it prefers soft, acidicconditions, seldom spawning in captivity.Size: 8 cm.Pangasius sutchi (Pangasiidae)An omnivorous species, the Siamese shark swims restlessly inshoals, and will need a capacious tank. There is no evidence ofsuccessful captive breeding. Size: 20-30 cm.93

FRESHWATER FISHATHERINIDAEThe Atherinidae are characterized by long,streamlined bodies which immediatelysuggest their speed and agility in the water.They are preponderantly marine species,with very few inhabiting inland waters.Telmatherina ladigesiSome experts consider that the Celebes rainbowfishbelongs to another family: the Telmatherinidae. T.ladigesi lives in shoals, preferring hard water anduncrowded conditions. The rays on the dorsal fin aremore developed in the male. Size: 6-8 cm• Bedotia geayiThe Madagascar rainbow appears more or lessindifferent to water quality and is a restless swimmer.It is reasonably straightforward to breed, as theparent fish will not devour the eggs, which sinkto the bottom and hatch in 5 days. Feed the fry onlive prey until they are ready for fine dried food.Size: 10 cm.MELANOTAENIIDAE (RAINBOWFISH)Commonly called rainbowfish, they come form the rivers and swamps of Australia and New Guinea.They thrive best in hard water with a pH above 7. Coloration varies according to mood, breeding condition,and hierarchical position. Water quality is not too important.Melanotaenia maccullochiSeveral closely-related species are marketed under the name ofMcCulloch's rainbowfish or dwarf Australian rainbowfish. All arerobust, demanding a large, uncluttered tank where they can swim inpeace - but make sure there is a planted area. The eggs - quite largeand hatching in 7-10 days - are fixed to plants by fine filaments: anunusual feature in aquarium fish. The fry remain clinging to a surface(the aquarium wall or a plant) until free-swimming; their initial growthis quite slow. Size: 10-12 cm.Melanotaenia boesemaniBoeseman's rainbowfish is one of the most colorful of thisfamily, and another which prefers hard water. Breeding isstraightforward, though the fry accept only tiny prey. Anothergorgeously colored species, M. herbertaxelrodi (Lake Teberarainbowfish), is sometimes available commercially.Size: 10-12 cm. •94

CYPRINODONTIDAE (KILLIES, ETC.)CYPRINODONTIDAEThe Cyprinodonts (meaning "toothcarps") flourish in virtually all the world's tropical inland waters(Australia excepted), with over 500 species in all. They have teeth, and their mouths are orientedupwards to seize prey on or near the surface; some species can even leap out of the water. They dwell incalm, stagnant, and shallow waters, sometimes mere puddles, which are liable to dry up. In this case, theadults perish, but their eggs survive: see Reproduction, page 60. They are small in size, rarely exceeding8 cm. vividly colored, and are prized by some enthusiasts for their remarkable breeding habits.There is much confusion between species, especially since coloration varies between geographicallydiverse populations. Only a few are regularly handled by dealers; most are exchanged between killiefanciers,killies or killifish being the popular name for these species.How killies reproduceThose killies whose habitat never dries out deposit sticky eggs which take several weeks to incubate.Those dwelling in areas prone to periodic drought have developed a special method to ensure the survivalof their species. The eggs spawned in the mud undergo a period of dormancy in their development(the diapause) for as long as the drought lasts. At the first rains, development resumes and the eggs hatch.Thus their incubation period may last from 3-6 months, and they have no need to be adhesive. You cantell that hatching is imminent when you can see theeyes of the embryos through the eggs.Caring for killies in the aquariumIdeally, you should provide a special small tank(10-15 liters) for each species. It is also possible toput males of different species in one tank; this willprovide a colorful spectacle, but do not put femalestogether, as many of them are so muchalike that you will have trouble tellingwhich species is which,Conditions must be soft and acidic, soyou will need to use peat filtration;sometimes, if you put a layer of peat onthe bottom of the tank, the fish will useit to lay their eggs on. The maximumtemperature should be 24°C. Killifish arevery fond of small, live prey, but willalso take dried foods.Preserving and transporting eggsHobbyists who live a long way from one another canexchange killie eggs through the mail. The incubationperiod is sufficiently long to enable them to be transported,as long as they are kept in damp, cool conditions.The seasonal species can withstand muchdrier conditions than continuous breeders: lowertemperatures serve to prolong the diapause.Make sure that the boxes or plastic bags used fortransport are completely airtight. To start the eggshatching, return them to water.95

FRESHWATER FISHAphyosemionSpecies of this genus inhabit most areas of Africaeast of Benin (formerly Dahomey), and particularlyfrom the Niger to the Congo. Seasonal species areless common than the continuous breeders ofdrought-free areas; some species exhibit breedingpatterns intermediate between both types.• Aphyosemion bivittatumThe two-striped aphyosemion reaches 6 cm in length, but itsgrowth is slow. The sticky eggs incubate in less than 2 weeks. It isa continuous breeder. Size: 6 cm.Aphyosemion walkeriWalker's aphyosemion or Walker's killifish is a seasonalbreeder. Kept in continually moist peat at 18-20°C, the eggs hatchin under 15 days. Size: 6 cm.Aphyosemion sjoestedtiThe eggs of the blue gularis, a seasonal killifish,incubate in 5 weeks at 22°C. Size: 12 cm. •• Aphyosemion gardneriThe exact coloration of the steel-blue killie variesaccording to its geographical origin. It is a continuousbreeder. The eggs hatch in 2-3 weeks. Size: 6 cm.Aphyosemion marmoratumThe marbled killifish employs an intermediate form ofreproduction. If you leave the eggs in the aquarium, incubationlasts 15-20 days, and hatching will be correspondingly staggeredKept in peat, they will take longer to hatch, but all the fry willemerge simultaneously. Size: 6 cm. TAphyosemion australe •The Cape Lopez lyretail or the lyretail panchax is obtainablefrom most commercial outlets and is the species of aphyosemionmost frequently recommended to hobbyists wishing to familiarizethemselves with the genus. It is hardy, and spawns continuouslywithout particular problems. Prepare a bed of peat in a small tank,introduce fine-leafed plants and keep the temperature below 23°C.The pH should be between 6 and 7, with almost zero hardness.The female lays 50-100 eggs, each only 1 mm in size, which hatchafter 2 weeks. Remove any infertile eggs (cloudy instead oftransparent). Hatching can be accelerated by raising the level ofdissolved CO 2 (carbon dioxide) - a technique also valid for otherspecies. One way to do this is by blowing gently down a tube intothe water. Size: 6 cm.96

Other Cyprinodontidae: Roloffia - Epiplatys - Aplocheilus - Fundulus - Rivulus —Nothobranchius - CynolebiasBesides Aphyosemion, there are several other genera popular with hobbyists. They are not normally availablefrom commercial outlets, but you can obtain them through clubs and aquarists' associations.Roloffia species are native to the African coastal countries west of Benin, unlike their close relativesAphyosemion. They prefer soft water (23-24°C maximum) and moderate levels of light.Epiplatys is a genus of killifish found from Senegal to Chad and even as far south as the Congo, in thewatercourses of tropical forests. They are continuous breeders, usually sticking their eggs to plants.The genus Aplocheilus consists of a small number of species native to Asia. Their breeding habits resemblethose of Aphyosemion.Fundulus is a genus originating from the United States - some species are found in Canada - and CentralAmerica. Specimens are rarely found on the commercial market. The eggs adhere to plants, hatching inaround 2 weeks.Rivulus, from Central America or the northern zones of South America, is a genus preferring calm waters,with a moderately warm temperature of around 24°C. Note that these fish can jump out of the aquarium.They are continuous breeding, laying eggs on plants or on the bottom.Nothobranchius species live in the waters of East and South-East Africa, in those areas with alternatingrains and droughts. Fish of this genus have more slender bodies than those belonging to Rivulus, but arejust as colorful.Cynolebias comprises seasonal killies from South America. Some species will even bury themselves inthe peat to lay their eggs. There are several species, closely related to the two illustrated below.Cynolebias nigripinnisThe black-finned pearl fish is a seasonalspecies; the eggs must be kept in peat for4 months. Size: 5 cm.Cynolebias bellottiiThe males of the Argentinian pearl fish willsometimes fight one another or harry the females.The breeding of this seasonal species is difficult. The eggsmust be kept for 3-6 months in moist peat; after replacement inwater, they hatch within a week. Size: 5-6 cm.• Rivulus cylindraceusThe female of the Cuban rivulus isarger than the male and can also bedistinguished by the black patch bordered withwhite on her caudal fin. The eggs (3 mm)incubate in around 15 days. There are no particularrequirements for water quality. Size: 7-8 cm.97

FRESHWATER FISHAplocheilus lineatusThe striped panchax requires a large tank, as it can reach 10 cmin length, with plenty of vegetation. The eggs are laid in theplants; the fry are tiny, and they require live prey small enough toswallow. Size: 8-10 cm.Epiplatys annulatusThe clown killie is only 3-4 cm long and is a top-dweller. It laysits eggs in fine-leafed vegetation; they hatch after 8-10 days.• NotobranchiusguentheriA seasonal, difficultbreeder, Gunther'snotho is smallbut veryhandsome. Youneed to preservethe eggs in peatfor 6-12 weeks; returnthem to water, and theywill hatch over a period of2 weeks. Size: 3-4 cm.A CYPRINODONT TO KEEP WITH CICHLIDS:LAMPRICHTHYS TANGANICANUSThis is a species of interest to anyone seeking tankmates forCichlids (see page 104). Both originate from the same habitat:Lake Tanganyika. L. tanganicanus, the Tanganyikapearl killie can reach 12 cm and its lively, shoal-swimmingbehavior makes it an ideal companion for Cichlids, thougha fascinating subject in itself. Unfortunately, you are unlikelyto obtain this species from your dealer.• Roloffia occidentalisThe golden pheasant is a seasonal species spawning in soft,acidic conditions. The diapause can last 4-5 months, sometimeslonger. The male is brightly colored, the female duller.Size: 8-9 cm.Roloffia geryi •A continuous-breeding species,Gery's aphyosemion can spawn every15 days. The eggs are only 1 mm in sizeand hatch in around 10-12 days. The fry growrapidly and can breed at the age of 3 months.Size: 6 cm.98

POECILIIDAEPOECILIIDAEThe Poeciliidae inhabit considerable areas of the American continent, favoring hard, alkaline, andsometimes even slightly brackish conditions where the water is rich in plant life and normally calm.This is a family of active, energetic fish, ideal for the beginner. They will accept any form of food, includingsmall, live prey, but appreciate extra vegetable material.The male is normally smaller than the female, though often more vividly colored. His anal fin, by a modificationof the third, fourth and fifth rays, has developed into a gonopodium (see illustration), a tubiformcopulatory organ, through which he deposits his milt (sperm) into thefemale's genital pore during a fairly brief pseudo-coupling. The female canthen produce several successive broods separated by a few weeks withoutintervention by other males, a feature which distinguishes this family from theGoodeidae. A darkish patch on her belly - the gravid spot, near the genital pore -signals imminent spawning in a ripe female. The eggs hatch inside her ovary; she thenimmediately expels the fry, often still in a curled, foetal position. These are much bigger than the fryof oviparous (egg-laying) fish: they are able to swim and eat fine artificial food on birth. To encouragereproduction, raise the temperature by a few degrees; the female will then spawn every 3-4 weeks.Poecilia latipinnaThis is known as the sailfin molly andshould be kept in identicalconditions to P.sphenops. (Both arepopularly referred to assimply the molly or blackmolly.) The dorsal fin is bothhigher and longer then that ofP. sphenops. The black lyretailvariety is probably a hybrid of thetwo species, rather than a variety ofone or the other. Size: 8 cm. •• Gambusia affinisft native of the southern United States, thespotted gambusia or mosquito fish hasbeen widely introduced totropical and temperate areas ofthe world. It is met insouthern France, for instance,close to the Mediterraneancoasts and even as far northas Bordeaux! These deliberateimportations were designed to reduceplagues of mosquitoes, since the fry arevoraciously fond of the aquatic larvae. In asense, then, it is not a "true" aquariumfish, but it is very sturdy and spawnsprolifically. You can raise it as live food forvoracious predators like the Cichlids; or forthose fish with a tendency to refuseartificial foods, like certain marine species,as it can survive a few minutes' immersionin salt water. Size: 5 cm.• Poecilia sphenops (molly)The common variety of short-finned molly or pointedmouthmolly has a silvery-gray body, with varying degreesof black spotting. The black variety is more popular withsome enthusiasts. The molly prefers hard water, to whichyou can add 1 % seawater - or 1 teaspoonful of table saltto 10 liters of water. It is also a good idea to feedsupplements of vegetable material. Size: 8 cm.99

FRESHWATER FISH• Poecilia veliferaThe Yucatan sailfin molly has anoverdeveloped dorsal fin. A black varietyexists, but it is less common than the "gold";the latter is rather incongruously named,since it is practically an albino, as its red eyesimply. Breeding is straightforward, and eveneasier if you raise the temperature a fewdegrees. The females can produce up to100 fry. Size: 15 cm.TRUE OR FALSE LIVEBEARERS?The term "livebearer" or "viviparous" is applied tofish of the following families: Poeciliidae,Hemirhamphidae, and Goodeidae. Their fry areborn live (already hatched), a phenomenon rareamong fish. In actual fact, the descriptions are scientificallyinexact in the case of the first two families:there is no anatomical connection betweenthe egg and the mother fish as there is in certainsharks and in mammals. Only the Goodeidae canbe classed as true livebearers, but aquarists commonlylump all three families together under thisheading.• Varieties of guppy, classified by dorsal finsPoecilia reticulataHalf-black red.Size : 5 cm. •Poecilia reticulataEven those who have neverkept an aquarium will haveheard of the guppy!Discovered in the middle ofthe 19th century, it is one ofthe most popular speciesowing to its uncomplicatedbreeding habits and the largenumber of available varieties,which are classified accordingto overall coloration and theshape of the caudal fin. Theguppy prefers hard, alkalineconditions, but it is extremelytolerant. A female canproduce up to 100 fry every4 weeks if the temperature israised to 27-28°C. Feralguppies are unspectacular incolor, with sometimes one ortwo black patches, and thefins are of normal size.Size: 5 cm.PoeciliareticulataSize: 5 cm. •PoeciliareticulataFeral guppySize: 5 cm. •basic variety pointed-tail spadetail lyretail top sword100

POECILIIDAEA LIVEBEARER FOR THE BEGINNER: THE PLATYXIPHOPHORUS MACULATUSIn addition to the guppy, the platy or Xiphophorus maculatus is an ideal starter fish.There are many varieties available commercially. They produce about 50 fry, and youcan cross the platy with the swordtail and Xiphophorus variatus (variegated platy or"variatus"). Common varieties of platy are:• red: one of the most popular;• lemon: cream-yellow body;• wagtail: red or orange-yellow, with black fins;• tuxedo: red and black;• black: blue- or greenish-black metallic sheen;• Simpson hi-fin: overdeveloped dorsal fin.• Xiphophorus helleriGold variety. Size: 15 cm.Xiphophorus helleriWagtail variety. Size: 15 cm.Xiphophorus helleriThe photo opposite clearly shows why X. helleri is known as theswordtail. A very lively fish, it can leap out of the aquarium, and themale is sometimes truculent. Females do not have the "sword."The female can produce up to 200 fry and exhibits behavior very rareamong fish and indeed all other animals: after one or two spawnings,she can undergo a spontaneous sex reversal, and function in allrespects like a male!Size: 15 cm.lower swordtail double swordtail flagtail delta fantail101

FRESHWATER FISHXiphophorus variatusThe variegated platy has fewer varieties than X. maculatus,with which it can be crossed. The female can produce up to100 fry. Size: 5 cm.• Xiphophorus montezumaeThis is the Montezuma swordtail. Most swordtails - thespecimen illustrated here is a feral variety - have shorter "swords"than X. helleri. They are rarely sold commercially. Size: 5 cm.VARIETIES OF SWORDTAILSwordtails are distinguished by their color and/or the shape ofthe finnage:• green: more or less bright green, with a broken red line oneach flank; probably closely related to the feral form;• red: entirely red body, the commonest variety;• tuxedo: red background, large black streak from back ofhead to caudal peduncle;• Berlin: red, spotted with black;• wagtail: red body, black fins;• black: in reality blue or green, with dark metallic sheen;• Simpson (hi-fin): highly-developed dorsal fin;• veiltail: all fins are larger than normal;• lyretail: upper and lower sections of caudal fin prolongedby filaments.• Xipho helleriRed veiltail variety. Size: 15 cm.Xipho helleriVeiltail variety. Size:15 cm. •Xipho helleriSimpson hi-fin varietySize: 15 cm.Xipho helleriGreen variety. Size:15 cm. T102

HEMIRHAMPHIDAE - GOODEIDAEThere are very few aquarists who have seen, let aloneowned, the wild stock from which captive varieties aredescended. These varieties do not exist in Nature, but theyare readily obtainable commercially. Some aquarists entertheir prize specimens for shows, where they are judged oncolor, shape, and the development of the finnage.How many varieties are there? At the present time, thereare five different color varieties of swordtail, plus anotherthree for fin shape. Given that similar figures would alsohold good for the platies, and that all species ofXiphophorus (swordtails, platies, variegated platies, etc.)can interbreed, the number of varieties becomes enormous;there's no way you'll remember them all!You sometimes hear aquarists remark that the present varieties,which have been patiently evolved through selection,are less hardy than earlier ones. Though the truth is somewhatmore complex, beginners, who are encouraged to trythese fish - mainly because they breed easily - may beslightly disappointed.THE POECILIIDAE: CROSSES AND VARIETIESHEMIRHAMPHIDAE -GOODEIDAEThe Hemirhamphidae (which are false livebearers)originate from Asia, where they live inhard, sometimes brackish waters. They are characterizedby a lower jaw which projects distinctly furtherthan the upper. The Goodeidae, natives ofMexico, are trtie livebearers. Contrary to what happenswith the Poeciliidae, the females produce onlyone brood after mating.• Xenotoca eiseni (Goodeidae)The red-tailed goodeid. The males, recognizable by their orangehindparts, are sometimes slightly aggressive.Gestation in the female lasts up to 2 months,with the fry (40-60) growing rapidly.Size: 7 cm.Ameca splendens (Goodeidae)The male butterfly goodeid is more brightly colored than thefemale, and his anal fin less clearly modified than in males of thePoeciliidae. Breeding requires hard water, with the addition ofsalt: 1 teaspoonful per 10 liters. Size: 8-10 cm.• Dermogenyspusillus(Hemirhamphidae)Dealers offer several species under this name. The Malayanhalfbeak proper lives and feeds just below the surface. Breedingis less prolific than with the Poeciliidae. The fry acquire thecharacteristic "beak" only after several weeks. Size: 7 cm.103

FRESHWATER FISHCICHLIDAECichlids have acquired a none-too-flattering reputation for trouble - persistently quarreling with other(and their own) species and wrecking the decor. But this is not always the case. There are more than1,500 species (related to the European perch), which throng the freshwater areas of America, Africa, and,to a lesser extent, Asia. Often quite large and powerful-looking, these toothed carnivores are voraciousfeeders. Their anatomical characteristic is the single, elongate dorsal fin. Some species possess a distinctpersonality and are decidedly temperamental; basically lively and boisterous, they can become quite belligerent,at least under certain circumstances, such as during spawning or in defense of territory.The breeding habits of Cichlids vary. One particularly interesting technique is mouthbrooding: the femaleshelters the eggs and fry in her buccal cavity, affording them a greater chance of survival.104

CICHLIDAE105

FRESHWATER FISHCICHLIDAE: AMERICAN SPECIESIn general these prefer slightly acidic, soft conditions, and sometimes appear sensitiveto any change in water quality. The aquarium (300-400 liters minimum for the largestspecies) must be equipped with hiding places and an efficient filtration system.Feeding is no problem: these fish particularly appreciate live prey and fresh foods. Theydeposit their eggs on a suitable surface: existing sites are usually sufficient. The exceptionsto the rule are the mouthbrooders.The genus CichlasomaThe genus Cichlasoma originates from Central and South America. These fish are consideredas potentially aggressive, especially during spawning, though some species remain reasonablypeacable. Because of their temperament and their size, it is important to keep themin large tanks: 200 liters for the smaller species and at least 400 liters for the largest. Thedecor should consist of rockwork and sturdy plants. These fish are omnivorous; there isno problem keeping them in captivity, but be aware that they are quite voracious.In general, the female is smaller than the male. She lays her eggs on a rigid surface whichshe has previously mouthed clean; the male then fertilizes them. After some 2 days incubation,they are carried to nursery pits hollowed out of the sand to encourage them to hatch. The hatchlingsremain there for a few days, while the male defends the territory.Cichlasoma (or Parapetenia) salviniThe adults of Salvin's cichlid are belligerent, but they take goodcare of their fry (several hundred per brood) which become freeswimming5-6 days after hatching. A 250-liter tank containinghard, alkaline water, is perfect for these fish, with some sturdywater plants as a finishing touch. Size: 15 cm.• Cichlasoma citrinellumThe Midas cichlid is rather aggressive, requiring a sizable tank: atleast 500 liters. The golden yellow coloration is less common in thewild, where most specimens are more or less gray. Size: 30-35 cm.CichlasomacrassumQuite timid andtranquil, despitereaching up to 30cm in length, theChocolate cichlidcan be recognizedby its bulbousforehead. A nativeof the Amazonbasin, requiring soft,acidic conditions anda large tank. •Cichlasoma maculicaudaThe blackbelt cichlid is equally intolerant, especially ofconspecifics. The female is capable of producing up to 1,000 eggsand the parent fish nurse the young for 3 weeks. The speciesprefers alkaline and moderately hard water similar to that found intheir home waters of Central America.Size: 15-20 cm.106

Mesonauta festivus (Old genus name Cichlasoma)Unlike other Cichlids, the flag cichlid - sometimes called thefestive cichlid, and not to be confused with the other flag cichlid,Aequidens curviceps - lays its eggs on vertical surfaces, while thelarvae are subsequently attached to another support by theparents. A temperamental fish: keep it separate from smallerspecies. Size: 20 cm.CICHLIDAE: AMERICAN SPECIES• Cichlasoma labiatumEasily distinguishable from related species by its large,blubbery lips, this species is commonly known as thered devil, and is aggressively territorial. It is best toseparate the parent fish from the young after hatching.It is easy to mistake the fast-growing juveniles for thegolden cichlid. Size: 20-25 cm.Cichlasoma nicaraguenseThe males of the spilotum grow up to 25cm in length, but the females are distinctlysmaller, and display brighter colorationduring spawning. The eggs are not adhesive- a rarity among Cichlids - and aredeposited at the bottom of a nursery pitdug into the aquarium bed.Cichlasoma octofasciatumFor a long time sold commercially under the name C.biocellatum, the Jack Dempsey (named after the boxer)is properly called C. octofasciatum. A bad character, this,and likely to savage the decor! On the plus side, it spawnsprolifically, producing 500-800 eggs. A'n interestingsubject for the more experienced aquarist moving on toCichlids. Size: 20-25 cm.CichlasomacyanoguttatumThe Texas cichlid has acolor pattern which variesaccording to its origin.Because of its size andbehavior - it is vigorouslyterritorial - it requires alarge aquarium. Watershould be alkaline andreasonably hard. Thefemale lays up to 600 eggs.Size: 30 cm.Thorichthys meeki(Old genus name Cichlasoma)To intimidate other fish, T. meeki enlargesits opercles (gill-covers), deploying itsbrilliant red throat membrane, which hasearned it the common name of firemouthcichlid. Despite its small size, it is actuallyquite belligerent. The dorsal and anal finsof the male are more pointed. The femalelays up to 1,000 eggs, which hatch in 48hours; the fry are free-swimming 4 dayslater. Size: 10-15 cm.A CICHLASOMA FORTHE BEGINNERCichlasoma bimaculatum, thetwo-spot cichlid, has a fairly calm temperamentand is a good subject for thehobbyist wishing to gain experience withCichlids. Its relatively modest size (15 cmmaximum) means it can be kept in a 200-liter tank with slightly smaller fish such assome of the Characins. The water should besoft and acidic. The female lays up to 200 eggs,and the fry grow rapidly.107

FRESHWATER FISHCichlasoma nigrofasciatumThe convict cichlid is a territorial fish which you will oftenfind playing bulldozers in your aquarium! It is besttherefore to avoid plants or delicately positionedrockwork. Selective breeding has graduallyevolved a xanthochromic (golden) variety,which is just as belligerent. Both strains caninterbreed with the redheaded cichlid, butthe hybrids inherit the convict's behaviorpatterns. Size: 15-20 cm. •Cichlasoma nigrofasciatumXanthochromic variety.Cichlasoma synspilumDespite its considerable size, theredheaded cichlid is fairly wellbehaved with other species,provided they respect itsterritory. Obviously, it requireshuge amounts of space, butspawns easily, with the femalecapable of producing 800 eggs.Size: 30 cm.Heros severumA native of the Amazon basin, theseverum thrives in soft, acidic conditions.Relatively tranquil except during spawning,it is one of the least prolific species ofCichlid, with the female laying onlya hundred or so eggs in a clutch.Size: 20 cm.AngelfishAngels are the most well-known and popular of allthe Cichlids. Their original habitats are the soft,acidic watercourses of the Amazon basin; they needan aquarium with a great deal of space, includingdepth, where they can swim without restriction.Plants, however, are also essential to form refuges.Angels are peaceful species - except during spawning- and you can keep them with Characins andCorydoras species in a regional South Americantank. You should not, on the other hand, introducesmaller species, which the angels are likely toregard as prey. Angels will accept manufacturedfoods, but they delight in small, live prey, which isthe best option.Both parent fish are involved in caring fortheir young. The female deposits hersticky eggs on broad-leafed plants (especially thoseof the genus Echinodorus) or on PVC pipe placedin the tank. She will sometimes choose other, surprisingsites, such as the aquarium glass or the heatingequipment! The male then joins the female inguarding the eggs and fanning them; hatching takesplace in 1-2 days. Sometimes, especially with thefirst clutch, the parents fail to fulfil their role andignore the eggs; remove the adults, and imitatetheir nursing behavior by positioning an airstone ordiffuser near the nest: this will stir the water andaerate the eggs.The fry, which do not resemble the adults, start tofeed on Artemia nauplii a few days after hatching.Whether breeding is successful or not, both theparent fish are able to mate againsoon afterwards.Pterophyllum scalareCurrently bred both in Europe andAsia, a long way from its nativewaters, the angelfish exists ina large number of varietiesclassified according to theamount and intensity of blackcoloration. Further, there areveil forms of practically everyvariety, sporting fins that aredistinctly longer than normal.Size: 10-15 cm.Pterophyllum altumThe deep angelfish iscaught in its naturalhabitat, and so is rarer andmore expensive to buy. It isdistinguished from itscousin by the sharpindentation just above eyelevel. Its care is not quite sostraightforward; the qualityof the water must be justright. Size: 1 5 cm. •108

DiscusA native of the Amazon and Orinoco basins, thediscus is often considered the most beautiful andregal of all freshwater fish. It lives in calm, clearwaters with soft and acidic properties. Tranquil andpeaceable, the discus is a leisurely swimmer,exhibiting stress reactions in the presence of livelierspecies. The best tankmates for it are Characins,species of Corydoras and Apistogramma or the variousangelfish.A large aquarium is necessary: allow 10 liters peradult, using a decor of suitably prepared bogwood,roots, and plants. Keep the temperature above 26°Cand make regular partial water changes. Vary thediet, which should consist mainly of live or freshprey. Breeding, considered extremely difficult,depends to a large extent on water quality: acidic,CICHLIDAE: AMERICAN SPECIESwith a pH of 6, or even slightly less; very soft, usingpeat filtration; temperature must be consistentlymaintained at 28°C.It is not easy to sex discus, but the adults pair offnaturally into breeding couples. The female lays hereggs (up to 200) on a vertical support (PVC pipe,plant pot, aquarium glass), with hatching followingin about three days; the fry remain attached by theirheads and only start swimming two or three dayslater, under the supervision of the parent fish. Themost extraordinary feature of these fry is that theyderive nourishment from a mucus secreted from theparents' bodies - a virtually unique phenomenon inthe entire fish world. Deprived of this criticalfeeding stage, they will not survive in the aquariumfor very long. Ultimately they can be fed onArtemia nauplii.Symphysodon discus discusThe Heckel discus has only three darktransverse bands. Unlike its cousins -the subspecies and varieties of S.aequifasciatus, which are mainly raised incaptivity - the Heckel discus is usuallyprocured from the wild. Tens of thousandsof fish of these species are exported everyyear; there is little data concerning thenfluence of these culls on the naturalpopulation, but these Cichlids do notappear to be endangered. As a matter ofnterest, the Heckel forms a modest foodresource, on a very localized basis, forcertain native populations. Size: 10-15 cm.Symphysodon aequifasciata •Brown variety. Size: 10-15 cm.Symphysodon aequifasciata •Breeding pair. Size: 10-15 cm.Symphysodon discus discus(three transverse bands; centralband always visible)• SymphysodonaequifasciataThe black stripes vary inintensity according to moodand behavior.Size: 10-15 cm.Symphysodon aequifasciata(nine transverse bands;visibility varies)SymphysodonaequifasciataThere are several naturalvarieties of discus,technically known assubspecies:- brown, basically brown,with blue streaks on head- green, with a lighter bodyand blue-green belly; the head andupper back show blue, wavy stripes- blue, much of whose body, especially the finnage, iscovered with blue streaks.Three other strains of discus have been bred selectively:- red, which has a red back and belly; the pelvic fins areblack, as opposed to red in other varieties- royal blue, blue body with brownish-red streaks- azure, a newcomer to the market, and apparently very hardto breed.Size: 10-15 cm.109

FRESHWATER FISHOther American speciesThere are still more American members of this family.Some of the smaller ones are deservedly popularon account of their coloration and behavior,while others are giants requiring an aquarium ofcommensurate size.• Aequidens maroniThe keyhole cichlid is tranquil, even timid, and needs a wellplantedtank with hiding places. Its breeding behavior is similar tothat of Aequidens curviceps, though producing fewer eggs.Size: 12 cm.Aequidens curvicepsThe flag cichlid, not to beconfused with Mesonautafestivus, which shares itsEnglish name, is a smallspecies from theAmazonian basin, andpeaceful enough except atspawning time. The femaledeposits up to 1,000 eggs on asuitable surface; both parent fishthen keep guard. The fry cling to theirsupport by means of a substance secreted fromglands on the head; when they become free-swimmingfeed them on Artemia nauplii. Size: 8 cm.Papiliochromis ramireziRamirez's dwarf cichlid is sensitive towater quality, so you will need to carryout regular, partial changes; it alsoprefers well-planted aquariums withplenty of hiding places. The female laysbetween 300 and 400 eggs on a flatstone. There is also a golden(xanthochromic) variety of this species,arrived at by artificial selection. Size: 6 cm. •Apistogramma agassiziiTranquil and peaceable, Agassiz'sdwarf cichlid demands regular waterchanges. The female cleans a solidsupport before laying up to 300 eggs.Size: 7 cm.Aequidens pulcherThe blue acara is a territorial species andcan be aggressive. The female lays200-500 eggs on a flat stone. Size: 15 cm.Astronotus ocellatusThe oscar grows to 30 cm and has a badreputation for wrecking the decor. Or, lessuncharitably, it has plenty of character, anddoesn't bother too much about the plantsas it barges about. The answer is to use avery large tank (several hundred liters) andtough, well-anchored vegetation. Bronzeand gold varieties of oscar have beenevolved by artificial selection. •• Apistogramma cacatuoidesMales of the cockatoo dwarf cichlid aremutually antagonistic. The female depositsher eggs on the roof of a natural cave oran artificial retreat such as a plant pot orpiece of PVC pipe. She then keeps guardover them, driving off all intruders. The fryswim 5-7 days after hatching. Size: 7 cm.110

NannacaraanomalaThe modest-sizedgolden dwarfcichlid likes soft,acidic conditions.The female laysher eggs on astone in a quietplace and thenguards them, evenagainst the male.Size: 8 cm.CICHLIDAE: LAKE TANGANYIKA SPECIESUaru amphiacanthoidesRather slow and timid for its size,the triangle cichlid is moreactive at spawning time, whenboth parents guard and fan the300 eggs. Care of this speciesdemands a tank with a minimumcapacity of 400-500 liters filledwith soft, acidic water.Size: 25-30 cm. •• GeophagusbrasiliensisThe pearl cichlid canexceed 20 cm in length and is highly teritorial; it isessential to keep it in a large tank with similar-sizedspecies. Tolerates water with average pH andhardness levels, but you will need to carry outregular changes.GeophagussteindachneriThe redhumpgeophagus is a placidspecies which loves toburrow in the sand.After laying, the femalegathers the eggs in hermouth, whence the fryemerge in 2-3 weeks,though they will dartback inside whenfrightened. Size: 20 cm.CICHLIDAE: AFRICAN SPECIESIn view of their size and behavior, most of the African species require a tank of some considerable size,powerful filtration, and few plants - the latter are in any case quite rare in the natural habitats. The watershould be distinctly alkaline (pH between 7.5 and 8, even higher for certain species) and hard. The bestform of decor is an imitation scree offering plenty of hiding places; for the majority of species, you willalso need to keep areas clear for swimming, though some prefer sandy zones. You can usually tell themales apart by their coloration. A large number of species practice mouthbrooding; the rest spawn in acave or on a suitable surface.Many of the Cichlids found in East African lakes are endemic, in other words, unique to the locality. Theexistence of localized populations sometimes gives rise to several strains of the same species, which aredistinguishable by coloration.Lake Tanganyika CichlidsSome 80-90% of Cichlids found in this lake areendemic; certain species practice mouthbrooding,the rest are substrate-spawners, i.e. lay eggs on asuitable surface or support. Some of the smallerspecies shelter in the empty shells of Neothauma,an aquatic gastropod.Cyphotilapia frontosaThe frontosa demands an aquarium containing a minimum of400-500 liters, with a decor of rockwork. It feeds on quite largeprey such as mussels or prawns. The adult males can berecognized by their bulging foreheads. Females aremouthbrooders. Size: 30 cm.111

FRESHWATER FISH• Julidochromis dickfeldiDickfeld's julie can be distinguished by itsbackground coloration, often darker thanthat of its cousins, and by the blue borderon the fins. Size: 8 cm.Julidochromis reganiOne of the largest julies, the stripedjulie or convict julie cangrow to 15 cm; otherspecies usuallymeasure 7-9 cm.The English namederives from thefour longitudinalbands. •Julidochromis transcriptusThe three bands of the masked julieare linked by black smudges. Likeother julies, J. transcriptus is rarelyavailable commercially.Size: 8 cm.AN AFRICAN CICHLID FORTHE BEGINNERThe behavior of Neolamprologus brichardi(lyretail lamprologus) makes it an ideal starter fish. It livesin shoals and is gregarious, save at spawning time, when itbecomes territorial. The eggs are laid on the roof of a cavewhich the parent fish will hollow out, sometimes under arock. The female cares for the eggs while the male standsguard over the nest; the fry are free-swimming some 8 daysafter hatching.The female can give birth again after 1 month; consequently,you may find several generations of brothers, sisters,and male and female cousins all living together. Themale looks after the older ones while the female tends theyoungsters. When they are a few centimeters long, even thefry join in defending the territory.In the wild, these species feed mainly on algae and plankton,but in captivity will take small live prey. Size: 10 cm.• Julidochromis marlieriMarlier's julie is remarkable for its brown-and-white checkerboardpatterning. Size: 10-12 cm.Julidochromis ornatusMales and females of the ornate julie pair-bond in apermanent, sedate relationship, even when notspawning. They seek out areas of rockwith hiding places and shelters where theycan reproduce. Several hundred eggs areattached to the roof of the spawning site;the female tends them while the male defendsthe territory. The fry are free-swimming after 8-10 days,under the watchful eyes of the adults. J. ornatus has threelongitudinal bands on a light background. Size: 8 cm. •112

CICHLIDAE: LAKE TANGANYIKA SPECIESTHE SHELL-SQUATTERNeolamprologussexfasciatusThough not particularlyaggressive, N. sexfasciatusshould not share a tank withsmaller species. The female laysher eggs in a shelter, on theunderside of the roof, with thefry not emerging till a week orso later. Size: 8-10 cm.Neolamprologus brevis (the dwarf shell-dweller) is ashy, even timid species. It spawns in the empty shell ofNeothauma, a snail which shares its habitat. When thefry grow to about 2 cm they seek out shells of their own.In the aquarium, you will need to provide a fine sandsubstrate, which you should then scatterwith different-sized snail shells (edible ormarine species) placed with the openingupwards. This is not an easy species ofCichlid to obtain. Size: 5 cm.Neolamprologus tetracanthusThe tetracanthus is a Cichlid which islikely to bully smaller species. It is fondof sandy areas furnished with plants -beds of Vallisneria for instance. It makes atiny cave at the base of a rock by burrowingaway the sand; the female then fixes her eggs(100-150) to the roof. Size: 1 5-18 cm.Neolamprologus leleupiRather aggressive, this is a solitary dweller. The female ofthe lemon cichlid lays some 200 eggs in a cave hollowedout under a rock, with the fry hatching in 3days and swimming freely a weeklater. Size: 8-10 cm.• Neolamprologus tretocephalusThe five-barred cichlid is belligerent and territorial, thriving,like all species of Neolamprologus, in tanks where there isabundant rockwork and the water is changed regularly. Thefemale lays 200-300 eggs in a cave. Size: 10 cm.Telmatochromis bifrenatusThe striped telmat is distinguishable from its cousin T.bhchardi by the presence of an extra longitudinal stripe,but sharing a virtually identical lifestyle; the female, forexample, also lays in a narrow cavity. Size: 8 cm.Telmatochromis brichardiA small, gregarious species dwelling in rockzones. The female lays her eggs in a very smallcave guarded by the male; the fry take severaldays to emerge. Its favorite food consists of liveprey. Size: 8 cm. •113

FRESHWATER FISHTropheus mooriiThe moorii seeks out rocky zones with clearwater and a supply of algae, and so requiressupplements of vegetable material incaptivity. The males will fight for territory. Thefemale incubates the eggs in her mouth; asthey are larger than those of other species, shecan only hold a small number, around 20 atmost. The coloration of juveniles differs fromthat of adult fish, which, in any case, varies -as does the exact shape - according to theiroriginal habitat. Size: 12 cm.Tropheus duboisiThe blue-faced duboisijuveniles are black with ascattering of white spotswhich disappear when thefish reach the adult stage,leaving a transverse whiteband halfway along thebody. T. duboisi breeds inan identical manner to T.moorii. Size: 12 cm.Cichlidae: Lake Malawi speciesThere are reckoned to be more than 200 species living in this lake, almost all endemic. The habitat consistsof rocky zones with hiding places and shelters, surrounded by clear, shallow, and well-lit water. TheCichlids feed on the algae encrusting the rocks - practically the only vegetation present.These fish require a fairly large tank (200-300 liters minimum for small species, 400-500liters for the largest) fitted with a powerful filtration system. Rocks will form the maindecor, but ensure the arrangement is stable, otherwise the more boisterous specimenswill dislodge it. The water must be distinctly alkaline, with a minimumpH of 7.5 - even 8 and over - and fairly hard: 5.6-8.4° GH (100-150 ppm).Cichlids are very fond of live or fresh prey, but they will accept granulatedartificial foods. Most species are mouthbrooders.Until the last few years, a certain numberof species were grouped within thegenus Haplochromis. Scientistshave now redistributed theseacross a variety of genera; however,the term "hap" (i.e.Haplochromine) is still commonlyused as a catch-all designationfor these endemic, mouthbroodingCichlids.114Aulonocara nyassaeThe Nyassa peacock is only aggressive towards conspecifics and until ahierarchy establishes itself among the males. It requires atank large enough for unrestricted swimming,with rockwork and a sandy substrate.After laying her eggs on a stone,the female incubates them in hermouth, where even free-swimmingfry will retreat if threatened. Thereare several varieties of A. nyassae,some of which could well be differentspecies. Size: 12 cm.Copadichromis boadzuluOn reaching 1-2 cm, fry of this speciesjoin groups controlled by a dominantmale. The female incubates 30-50 eggsin her mouth for around 3 weeks.Size: 12 cm. •

CICHLIDAE: LAKE MALAWI SPECIES• CyrtocaramooriiThe adults of the bluelumphead have abulging forehead, moreprominent in themales. Rather timid, C.moorii seeks out sandyareas of the lake bedwith rocks todemarcate its territory.The female incubatesthe eggs in her mouthfor 3 weeks. Size: 20cm.Sciaenochromis ahli •A rather shy and timid "hap"; the male is blue,the female grayish with dark transverse stripes.Size: 12-15 cm.Copadichromis jacksoni (female)Sometimes confused with Sciaenochromis ahli,this species is actually larger. Juveniles have twodark patches which usually disappear inadulthood. Size: 18-20 cm.• Dimidiochromis compressicepsThe long, flat head and slim, elongate body characterize theMalawian eye-biter, whose name derives from its reputation fordevouring the eyes of other fish. It swims with head tilted slightlydownwards ready to seize its prey. A typical habitat would be asandy bed with plantations of Vallisneria.Size: 15-20 cm.• Nimbochromis livingstoniiThe Livingstone's mbuna is somewhat pugnaciousand bullies smaller species. The dominant male takeson a blue, metallic coloration, while the females -who incubate their eggs for 3 weeks - exhibit brownspots on a light background. Size: 20 cm.• Nimbochromis linniThe elephant-nosepolystigma, or Linn'shaplochromis, a native of Pacificwaters, is easily confused with aclosely related species, N.polystigma (English name: thepolystigma) but has a downwardtiltedmouth. The female incubatesup to 300 eggs for 3 weeks; thefry are free-swimming when theyreach 1 cm. Size: 20 cm.Nimbochromis venustusThe Latin name of the genus Nimbochromis refers todistinctive patches of dark coloration on the body. Thedominant male of the venustus has a yellow bodyand blue head. The preferred habitat is asandy area with beds of Vallisneria.Size: 20 cm. •115

FRESHWATER FISHProtomelas annectensA shy and timid species. The male of theannectens prepares a burrow in the sandfor the female's eggs, which he thenfertilizes. She incubates them in her mouthfor 2-3 weeks; the fry emerge from theirrefuge when 7-8 mm in size. Size: 15 cm.Protomelas similisThe dark stripe extendinglongitudinally from the gillcoverto the tail of the redempress can lead to confusionwith P. annectens.Size: 15-20 cm.Placidochromis electraThis species (deepwater hap)feeds on tiny particles which itextracts from the substrate byfiltering it with its mouth. Theeggs are laid in a burrow duginto the sand, with the femaleincubating them for 8 days inher mouth. The fry leave theirrefuge after 2 weeks.Size: 15-20 cm. •Under the general name of Mbunas are grouped the genera Pseudotropheus, Labeotropheus,and Melanochromis, which display certain behavioral similarities. They are active fish, livelyand quarrelsome, especially at spawning time or when defending territory: in the localAfrican dialect M'buna means "stone-striker." In most cases, it is advisable to segregatethem in a species aquarium and not to mix larger with smaller specimens. Mbunas arehardy, but sensitive to any reduction in oxygen level.Breeding can take place in the community tank. The (polygamous) males are distinguishableby their coloration from the females, which incubate the eggs in their mouths forsome 3 weeks. Mbunas are difficult to categorize owing to variations in color among localpopulations and to the more orless regular stream of new commercialimports.Labeotropheus fuelleborniFuellebom's cichlid can be recognized byits curious parrot-beak snout. It requiressupplements of vegetable material. Thereare several varieties or subspecies foundin different parts of Lake Malawi.Size: 10-15 cm.• Labeotropheus trewavasaeThe Trewavas Malawi cichlid -yellowside variety. L. trewavasae has aslimmer body than L. fuelleborni and willdefend its territory vigorously. Its diet isessentially herbivorous, but it will alsoaccept small crustaceans. Size: 8-10 cm.• Melanochromis auratusThe Malawi golden cichlid is the mostbelligerent of all Mbuna species, especiallyin the case of the dominant male. Thefemale deposits her eggs in an out-of-sightnest while the male keeps guard; he isrecognizable by two dark horizontal stripeson a light background, a patterningreversed in the female. Size: 8 cm.

MBUNASMelanochromisjohannii •Is very agressive - even thefemales attack each other.This fish readilyaccepts vegetablesupplements. Themale is dark withhorizontal stripes, thefemale golden yellow.Size: 8-10 cm.• Melanochromis craboA territorial and highly hierarchical species. The femalechameleon cichlid lays her eggs on a flat stone, thenretires to a quiet place to incubate them.Size: 8-10 cm.Pseudotropheus elongatusThe slender Mbuna has a more streamlined bodythan other Pseudotropheus species. The basiccoloration is blue, but details vary extensively; the malehas eye-spots {ocelli) on the anal fin. Size: 12 cm.Pseudotropheus zebraThe Malawi blue cichlid was one of the first Mbunasknown to aquarists. Its diet is mainlyherbivorous. There are several color morphsof P. zebra (blue or orange, for instance);some may in fact be closely relatedspecies. Size: 12-15 cm.PseudotropheustropheopsThe tropheops is one ofthe largest Mbunas andcan measure up to 18 cm.The male displays a violetbrowncoloration; thefemale is dark yellow.Supplements of vegetablematerial are desirable. •Pseudotropheus lombardoiThe male kennyi is golden yellow, the female blue, with black transversebands; unlike other Mbunas; juveniles assume these colorations on reaching3-4 cm. The female retires to a quiet area of the tank to incubate her eggs.Size: 13-15 cm.Pseudotropheussocolofi •Unlike other species inthis group, the maleand female cobalt bluecichlid are scarcelydistinguishable. ThisMbuna is aggressiveand defends itsterritory ferociously. Itappreciatessupplements ofvegetable material.Size: 13 cm.117

FRESHWATER FISHCichlidae: other African speciesBesides the Cichlids of Lake Malawi and Lake Tanganyika, a few moreinteresting species are found in other, lesser-known lakes, and in certainrivers in East and West Africa.Pelvicachromis pulcherThe kribensis is a native of Nigeria; it thrivesin hard, even brackish waters with abundantvegetation. The female lays 200-300 eggs ina cave, tending them while the male defendsthe site, though he is less aggressive thanother Cichlids. The fry are free-swimming 1week after hatching.Size: 10 cm. •Astatotilapia burtoniBurton's mouthbrooder is aspecies encountered in the Nileand East African lakes. It ismore or less tranquil,but becomes territorialduring spawning. Thefemale lays her eggsin a hollow dug into thesubstrate and then incubatesthem in her mouth for 2 weeksin a secluded part of the tank.Size: 10-15 cm. •HemichromisbimaculatusSeveral related species aresold under the name ofcrown-jewel cichlid, theferal varieties having a moremarked red coloration. Themale will defend its territoryvigorously; the female lays up to500 eggs on a suitable surface, withthe fry swimming within a week.Size: 10 cm. •OREOCHROMISNILOTICUSAn algae- and plankton-eater in the wild, the Nilemouthbrooder becomes omnivorous in captivity.It grows fairly rapidly, and is very hardy: it can withstanda temperature range of 13-33°C and alsosurvive in salt water after careful and progressiveacclimatization.Originally from the Nile, Chad, and Senegal, it hasbeen introduced into practically the whole of tropicalAfrica, including Lake Victoria. Fishing for thisspecies provides an important local source of food,but the largest specimens (often destined for smoking)are becoming rarer since the introduction of avoracious predator, the Nile perch or Lates niloticus.This fish, which can exceed 1 m and weighmore than 100 kg, is a notorious example of badpractice: importing a non-native species withoutproper precautions. However, the population levelsof small Cichlids in Lake Victoria do not seem tohave been affected.O. niloticus has also been introduced into many ofthe world's tropical regions, where it is raised on alarge scale to improve food resources. At themoment it is not in great favor with hobbyists.Size: 30-50 cm.Oreochromis mossambicusThe Mozambique mouthbrooder has been introduced into several tropicalregions of the world. A large female can incubate several hundred eggs in hermouth for 3-4 weeks. The adults acclimatize well to seawater; the fry canwithstand a progressive increase in salinity over 4-6 weeks from the time theyare 1 cm long and are consequently useful for feeding as live prey, especiallyto marine species. Size: 50 cm.118

CICHLIDAE: ASIAN SPECIESTilapia mariaeThe tiger tilapia can be extremelyaggressive when defending its territory.The female lays up to 400 eggs on asuitable surface and then keepsguard until they hatch 2 dayslater. Size: 20 cm.Pseudocrenilabrus multicolorThe dwarf Egyptian mouthbrooder is a smallCichlid dwelling in the Nile and LakeVictoria which will defend its territoryagainst larger species. The femalelays up to 100 eggs in a depressionhollowed out of the sand and thenincubates them in her mouth for around10 days. Size: 8 cm. •Steatocranus casuariusThe bellicose lionhead cichlid or African blockhead has its homein fast-flowing, turbid waters. The characteristic protuberance onits forehead is larger in the male. The female lays 100-200 eggs ina hollow, which both parents will guard. Size: 10 cm.• Tilapia buttikoferiThe female hornet tetra lays 200-400 eggs on a stone. Theparents become very aggressive, defending both eggs and fry.Extra vegetable material should be added to the diet. Size: 30 cm.CICHLIDAE: ASIAN SPECIESVery few in number; in fact, the hobbyist is likely tocome across only two species.Etroplus suratensis •In view of its size, the banded chromide requires a good-sizedtank. It does best in hard, brackish water. Size: 20-30 cm.Etroplus maculatusThe orange chromide also likes hard, brackish waters withabundant vegetation. A tranquil species which spawns quiteprolifically, with the female laying 300 eggs on a suitable support.The newly hatched fry are then carried to a hollow dug out of thesand. There is also an all-gold variety of this species. Size: 8-10 cm.119

FRESHWATER FISHBELONTIIDAEThese fish possess an unusual feature: located in the upper part of the head is a special organ knownas the labyrinth - hence their earlier name of Labyrinthidae. They were also formerly known asAnabantidae (meaning "climbers"), since some can scramble out onto land. The labyrinth, in fact, allowsthem to breathe oxygen from the atmosphere. This process is supplemental to the normal function of thegills and represents an adaptation to their habitat, developing in juvenilesduring the first few weeks of life. The underlying reason is that Belontiidae,natives of Asia, live in environments deficient in oxygen: standing water,stagnant and often muddy, including pools and rice paddies. The pectoral finsof certain species have developed thread-like organs which have a tactilefunction and help the fish find its direction.Betta splendensThe Siamese fighting fish only partly deserves itscommon name: the males are aggressive towards oneanother - and to females after spawning - but theydo not interfere with other species. The females arealways mutually tolerant. A handsome male (red, blue,or green) can therefore be kept in a regional orcommunity tank. As soon as the female has laidher clutch of several hundred eggs, she must beremoved, as she runs the risk that her mate willattack or even kill her. Incubation takes 2 days;remove the male after hatching. The fry will developrapidly. Size: 6-8 cm.Betta splendensMales.Betta splendensA ripe female.Colisa fasciataMales of the giant gourami will battlefor dominance. The females lay over100 eggs in soft, acidic water. Thisspecies interbreeds with the thicklippedgourami: dealers market theresulting hybrids under either name.Size: 10 cm. •Colisa sota (Colisa chuna)The honey gourami does not always construct anest for spawning: the male carries the fry aboutuntil they are free-swimming. A gregarious buttimid species. Size: 5 cm.• Colisa labiosaThe timid thick-lipped gourami hides in thevegetation whenever it feels threatened. The femalelays several hundred eggs in soft, acidic water.Size: 10-12 cm.120

BELONTIIDAETrichogasterleeriThe male of thepeaceful pearlgourami has amore pointeddorsal fin than thefemale, which canlay up to 1,000eggs. The fry areslow to develop.Size: 13 cm.Macropodus opercularisThe paradise fish has been familiar toaquarists since the mid- 1800s. It is the"black sheep" of the family, butpossesses the advantage ofwithstanding temperaturesdown to 15%C -sometimes even lower forshort periods. The female laysseveral hundred eggswhich hatch in 2 days orso. Size: 10-15 cm.Helostoma temminckiThe kissing gourami is a near relative of theBelontiidae - it actually belongs to the familyHelostomatidae - and like them possesses alabyrinth, and builds a bubblenest for its eggs.The "kissing" behavior observed betweenindividuals probably has some social function;it is not necessarily linked to reproduction,though admittedly also occurring during themating ritual. Size: 10-15 cm.Trichogaster trichopterusTrichogaster trichopterusThe tranquil blue gourami or threespotgourami prefers to breed inseclusion from other fish.The current variety hasonly two blackspots on its body- the third spotreferred to inits Englishname isreally theeye. Thesespots arenot presentin the Cosbystrain. There isalso a mostbeautiful goldenvariety, which is not albino. Size: 10 cm.A GOURAMI FOR THE BEGINNERThe Siamese fighting fish (Betta splendens) isthe traditional recommendation to the novice: themale makes a glorious sight in the aquarium.If your aim is to familiarize yourself with breeding procedures,it is better to try the blue gourami or the dwarf gourami.The latter (Colisa lalia) is tranquil and timid, retreating into thevegetation if disturbed. The female,less brightly colored than themale, is very prolific. Theeggs hatch in 2 days,with the fry feedingon small live prey.There is also anorange-red versionof thisspecies - thesunset. Once again,the female is duller incolor. Size: 5 cm.121

FRESHWATER FISHCURIOSITY CORNERSome species, often possessing unique anatomicalfeatures or biomechanisms, exist only as asingle family in the world of the aquarist - andsometimes also in the wild. For these reasons wehave grouped them together on this double page.Notopterus chitala (Notopteridae)The Indian knifefish or clown knifefish lives in Asiain slightly alkaline waters. It can swim both forwardsand backwards, and tends to be nocturnal. Severalspecies have proved marketable; one of them,Notopterus notopterus, which has only recently beensuccessfully bred in captivity, is used as a food sourcein certain parts of the world. Size: 20-30 cm. •Gnathonemus petersii(Mormyridae)Peters's elephantnoseuses its "trunk"to sift the substratefor food, preferablyin darkness, as it israther timid. Theelephant-nose canemit weak - and quiteharmless - electricaldischarges.Size: 15-20 cm.Pantodon buchholzi •(Pantodontidae)The butterfly fish is a surfacedweller,gulping down its prey (ithas a preference for live food) withits yawning mouth. Sometimesaggressive, it can leap from thewater. Its common name derivesfrom its butterfly-like appearanceas it swims with pectoral finsoutspread. Size: 12 cm.Xenomystus nigri(Notopteridae)The African knifefish isdistinguishable from N. chitalaby the absence of a dorsalfin, but resembles it inbeing a twilightspecies. Occasionallyit emits a groan-likesound from thepneumatic duct,which links theswim bladder tothe digestive tube.Size: 10-20 cmEigenmannia virescens(Rhamphichthyidae)The green knifefish originates fromcalm waters in South America, andtherefore prefers soft, acid conditions.Another more or less twilight species,it appreciates live prey. Appears not tobreed in captivity. Size: 20-30 cm. •122

CURIOSITY CORNERA DISGRACEFUL PRACTICEThe coloration of the back and belly is absent in feral varietiesof the glassfish (Chanda ranga). A practice current in South-East Asia consists of injecting the fish with chemical dyes. Thisis more than questionable - it is downright unacceptable andought to be stopped. We suggest very strongly that you boycottthe purchase of such specimens; in any case, the colorationachieved is not permanent.• Chanda ranga (Centropomidae)The natural habitats of the glassfish are hard, brackish waters inAsia. This is a peaceable species, but hard to breed. The femalelays a hundred or so eggs in the fine-leafed foliage of certainplants. The tiny fry must be fed on infusoria of a suitable size.Size: 5-6 cm.Polycentropsis abbreviata (Nandidae)The African leaf fish really does resemble a leaf - acamouflage used to outwit its enemies. Its deformable mouthmeans that it can swallow prey measuring up to half its ownsize. There are several related species; one of them, whichbelongs to the genus Monocirrhus, swims at an obliqueangle, head down, and has a small barbel onits lower jaw. Size: 6-8 cm.Mastacembelus sp. (Mastacembelidae)Several color variants are sold commercially under the name ofMastacembelus or spiny eel. The long snout acts as anorgan of touch: only the head remainssticking out when the fishburies itself in the sandfor protection. It isbest to keep only onespecimen, otherwisethere will be constantfighting. Be careful toothat this species doesnot escape from thetank, as it is very agile.Breeding in captivity isimpossible withouthormone injections.Size: 20 cm. •123

BRACKISH WATER SPECIESSome species cope well with conditions where there are large variations in salinity. In the case of others,juveniles start their lives in fresh water before descending to estuaries, where they complete theirdevelopment; once grown to adulthood, they live permanently in the sea. It is vital to keep such fish inspecial aquariums where the salinity is carefully adapted to suit their metabolisms. You will find severalspecies available on the market; some possess really remarkable features and are regarded by aquarists ascuriosities. However, few hobbyists think of actually keeping a brackish water aquarium, though this canbe just as exciting as a freshwater or marine tank. Some of the species described below will coexist quitehappily in the controlled environment of an aquarium.Monodactylus argenteus (Monodactylidae)The mono begins its life in fresh water, with the juveniles migrating tobrackish regions as they mature. The adults are true sea-dwellers. This speciesrequires a large tank with enormous amounts of space for group swimming. Atimid species, it prefers live prey or fresh food. A near relative, M. sebae (thefingerfish), is partially herbivorous. When in poor health, or when the waterquality is unsuitable, the coloration of both species darkens; normally, thesilvery background predominates. Size: 15-18 cm.Brachygobius xanthozona (Gobiidae)The bumblebee fish comes from the coastal regionsof South-East Asia. Its pelvic fins are modified into asucker, which allows the fish to attach itself to asupport and resist the current. It feeds on small, liveprey and rarely breeds in captivity. Size: 5 cm. •Periophthalmus sp. (Gobiidae)The genus Periopthalmus contains some very bizarre fish whichcan leave the water and move around using their pectoral fins.They are found in all the world's tropical regions, exceptAmerica, living in the sandy areas of estuaries. Caring for themin captivity requires an aquaterrarium rather than a simpleaquarium; they need a bank of sand, with a gentle slopeallowing them to emerge from the water, which should notexceed 15 cm or so in depth. Captive breeding is very rare.The two species most commonly available commercially are P.barbarus (blotched mudskipper) and P. papilio (butterflymudskipper). Size: 10-12 cm.

Toxotes jaculator (Toxotidae)The archer fish has its "hunting ground" just belowthe surface. To capture small insects for food, it shootsout a powerful jet of water, knocking down the prey,which it then snatches with its mouth. Its preciselyaimed "shot" is made possible by excellent visionthrough both water and air; the jet can hit a target upto 1 m away. A territorial species, sometimes aggressive,and requiring hard, brackish water. Not known to breedin captivity. Food consists chiefly of living prey:preferably insects, otherwise tubifex or the fry ofPoeciliidae. Size: 15 cm. •Scatophagus argus (Scatophagidae)Adults of the spotted scat can survive in fresh water, but aremuch less active than in salt conditions. This is a gregarious fishwhich requires vegetable supplements. The species 5. rubifrons(tiger scat) is probably only a variety of 5. argus. Scats are muchmore prone to disease if kept in fresh water, and thrive best inbrackish or saltwater aquariums. Appears not to have been bredsuccessfully by hobbyists; in any case, only reproduces in brackishwater. Size: 20-25 cm.Tetraodon fluviatilis (Tetraodontidae)A few species of Tetraodontidae, a marine family for the mostpart, live in brackish water. The round-spotted puffer, thecommonest, can become aggressive on reaching adulthood. Itfeeds voraciously on small snails, but will also take live prey. Itappears that this puffer can be bred in captivity by using brackishwater and keeping the temperature above 26°C. Size: 7-10 cm. T• Tetraodon palembangensis or T. biocellatus(Tetraodontidae)Several related species are marketed under the general name ofTetraodon; T. palembangensis is known as the figure-eightpuffer. When threatened, all species can inflate their bodies withair and water to intimidate the enemy; they have teeth, and canfeed on mollusks and crustaceans. Tetraodon reticulatus(reticulated puffer) is aggressive and frequents distinctly salinewaters. It accepts live prey or meat-based foods; it is not knownto breed in captivity. Size: 8-10 cm.

MARINE FISHThere are almost 20,000 species of marine fish in the world, but only asmall minority is of any interest to the aquarist. Of these, most comefrom the Pacific and Indian oceans, although a few are native toAustralia and the tropical Atlantic ocean.Marine fish are usually collected in their natural environment andrarely reproduce in captivity. They find it more difficult to acclimatizethan freshwater fish, particularly as regards feeding: some refuse to eatartificial food, and others have very special dietary requirements.The smallest marine fish require a minimum water volume of 150-200liters. Medium-sized species (around 20 cm) must he kept in tanks of300 liters, or at least 400 liters if they are active. It is advisable to obtainjuvenile (or sub-adult) specimens, as they are generallyeasier to acclimatize and feed.

COHABITATION OF MARINE FISHBearing in mind their behavior (aggression, need for territory, group life), not all marine fish can live together in the same aquarium,and any mistakes in this respect may prove tragic for your residents.The table below therefore indicates how to fill a marine tank, on the basis of the characteristic traits of each species.MARINE FISH FOR BEGINNERSThe term beginners refers here not only tonewcomers to fishkeeping, whose first tankwill be a marine one, but also to aquarists who havealready had experience with freshwater tanks. Beginnersare recommended some species of clownfish (Amphipriondarkii and A. sebae) and blue damsels, all of whichbelong to the Pomacentrid family. Also suitable are thesmaller Labrids and the Blennies (family Blenniidae). Themore experienced can try, in addition to these species,other clownfish and damsels, as well as some more regalspecies: queen angelfish (Holacanthus ciliaris,Pomacanthidae), auriga and raccoon butterfly fish(Chaetodon auriga and C lunula, Chaetodontidae), clownand hippo tangs (Acanthurus lineatus and Paracanthurushepatus, Acanthuridae).FOR THE EXPERIENCED,MORE DELICATE MARINE FISHOnce an aquarist is familiar with the problems of marineaquariums and how to deal with them, he or she can investigateother, more delicate species: annularis angelfish(Pomacanthus annularis), some dwarf angelfish such asCentropyge acanthops (yellow and blue angelfish), all fromthe Pomacanthid family, the Naso and Zebrasoma genera(Acanthuridae), yellow boxfish (Ostracion cubicus,Ostraciontidae), foxface fish (Lo vulpinus, Siganidae).On the other hand, some species can be recommended onlyto the most experienced hobbyists: the Pakistani butterfly(Chaetodon collare), the copperband butterfly (Chelmon rostratus),the yellow longnose butterfly (Forcipiger flavissimus),all from the Chaetodontid family.Also considered delicate are the Acanthuridae, Balistids andPomacanthidae not mentioned above, and the Zanclidae.

MARINE FISHHOLOCENTRIDAEThese are most active at night, their large eyes endowingthem with good vision to detect their animal prey. Theyremain hidden by day, and so must be provided with shelters,and a tank of at least 300 liters capacity.Adioryx cornutusThe squirrel fish is a placidspecies which lives alone. It iseasy to keep, though it mustbe given live food, such as smallfish. Size: 14 cm. •Myripristis murjdanRobust and sociable, the red soldier fishhunts small, live prey, mainly at night. Itmust be furnished with some hideaways.Size: 18 cm.Myripristis jacobusSpecies related to M. murjdan.Size: 18 cm.AdioryxspiniferIts bright redcoloringdistinguishes itfrom the Adioryxcornutus, but itslifestyle is verysimilar.Size: 20 cm.LUTJANIDAEThe Lutjanids (or snappers) frequent coastalwaters, but not necessarily reefs. They arevoracious fish, equipped with strong, pointed teeth,and need a large tank and enough space to enablethem to swim in small groups. Lutjanids enjoy livefood but canalso be givenpieces of fish,mussels, orshrimps.• Lutjanus sebaeThe red emperor snapper lives close to corals. The adults, whichare often solitary, are not always able to tolerate each other. Thisspecies must be put in a large tank with suitable hiding places.Size: 20-30 cm.128

PLECTORHYNCHIDAELutjanus sanguineusThe blood red snapper has agood appetite and appreciates smallfish. The juveniles have a dark band running fromthe eye to the base of the dorsal fin, but this is notvery evident in adults. Size: 30-35 cm.• Ocyurus chrysurusThe yellowtail snapper is native to thetropical Atlantic. This strong swimmer likesto eat fish and small crustaceans. Rarelyfound in aquariums (regrettably, because itis a magnificent species), it needs a largetank, proportional to its size. It must bekept alone. Size: 30-40 cm.Lutjanus kasmiraThe juveniles of the eight-stripe snapper have lessvivid coloring than the adults and a black spot on thebody. Its diet consists of small fish and crustaceans.Size: 35 cm.PLECTORHYNCHIDAEThe young live in groups; their coloring differsfrom that of adults, which are more solitary.They are bottom-feeders, often sifting the sandto capture small, live prey. Inaquariums they can be graduallyadapted to artificial food. Theyneed a large tank with shelters.Plectorhynchus chaetodontoidesThe spotted sweetlips lives alone (or in very small groups) incoral reefs. The white spots on the juveniles disappear when theybecome adults. They are barely active by day, and need a big tankto feel at home. Size: 20 cm.• Plectorhynchus gaterinusThe young fish sport horizontal bands, while the adults are brightyellow with dark dots. The black-spotted sweetlips is a peacefulfish that feeds on adult brine shrimp or other animal products.Size: 20 cm.Plectorhynchus orientalisThe zebra sweetlips acclimatizes easily when young. It is quitevoracious, and relishes shrimps, morsels of fish, or other animalproducts. There are several related species with horizontal bands.Size: 20 cm.129

MARINE FISHSERRANIDAEThere are more than 400 species of Serranids inthe world (including the groupers found inEuropean seas) and some are easy to keep in alarge aquarium (at least 400 liters). Serranids arerobust and live alone once they become adults. Themouth of these voracious carnivores allows them toswallow small fish or large pieces of fresh food.• Cephalopholis argusYou can train the black groupeto eat out of your hand. It can brecognized by its brown coloringspeckled with white dots. Size: 20-30 cmCephalopholisminiatusThe solitary redspottedgrouperlives somewhathidden in corals. Itcan live for over 5years in anaquarium. Thecoloring growsdarker in adults.Size: 20-30 cm. •Cephalopholis urodelusThe white line grouper can berecognized by the two oblique white barson the caudal fin. It is placid by nature andlikes to have hideaways.Size: 20-25 cm.Cromileptes altivelis •The patches on the younggrow less pronounced inadults. The panther snappercan grow up to 65 cm in thewild, and in an aquarium it canreach 30-40 cm. It stalks itssmall, live prey and suddenlypounces on them. This speciesdoes not succumb easily tocommon parasitic diseases.Several specimens can livetogether in a large tank.• • Pseudanthias squamipinnisThe scalefin anthias lives in a group or shoal, dominated by a fewmales. This pretty little fish can live in a fairly small tank (minimumof 200 liters) furnished with hiding places. It feeds on plankton inthe wild and prefers small items of food, particularly live prey. Thisfish is sometimes classified in the Anthiid family. Size: 12 cm.130

SERRANIDAEHamletsThe Serranid family includes the species belonging to the Hydroplectiis genus, native tothe tropical Atlantic, that are small in size and therefore much appreciated by aquaristswho have only a 200 liter tank. These fish live alone and hide in crevices in the decor.They feed on crustaceans, worms, and small fish.Hypoplectrus gemmaLike the other species in this genus, the bluehamlet is aggressive and can only be kept ifthere is no other fish of the same species.Size: 10-11 cm. •Hypoplectrus guttavariusThe coloring of the shy hamlet variesfrom one specimen to the next.Size: 12 cm.• HypoplectrusgummiguttaThe golden hamlet ischaracterized by a black triangularpatch in front of the eye. All hamletsare hermaphrodite, i.e. they areendowed with both ova and spermatozoa,but they can only use one or the other. Inother words, they cannot fertilizethemselves. Size: 13-14 cm.Hypoplectrus indigoThe indigo hamlet, bigger thanthe blue hamlet, is distinguishedby its vertical bands, which arepaler than its background color.Size: 15 cm. •131

MARINE FISHCHAETODONTIDAE (BUTTERFLY FISH)The butterflies are some of the most beautiful ofall marine fish, on account of their vividcoloring. They are widespread in the tropical seas,where they live in coral reefs, either singly or ascouples, generally staying close to the coast. Thejuveniles often have a different coloring fromadults, which can cause some confusions betweenspecies. Butterfly fish generally have a specializeddiet, according to the species: some graze on algae,some eat the tentacles of anemones or coral polyps,while others prefer different kinds of invertebrates.This sometimes leads to acclimatization problems,as they will not accept a normal diet. They musttherefore be trained to eat other food: adult brineshrimps, worms, pieces of mussel, small shrimps. Ifthey refuse this type of food they will soon die. TheChaetodons are considered the most demanding offish as regards living conditions. This means thewater must be of excellent quality - thoroughlystirred, filtered, and oxygenated - and regularchanges, in small quantities, are beneficial. Thetemperature must be a minimum of 26°C, and thespecific gravity 1.022-1.023-Generally speaking, it is only possible to keep oneChaetodon per tank: they are territorial and do notreally get along with each another, although theydo accept fish from other species. Nevertheless,invertebrates are out of the question as cohabitants.The decor should consist of blocks of coral,through which they can weave about in comfort,thanks to their body form, but they must be givensufficient free space for swimming and feeding.Chaetodon chrysurusThe red-tailed butterfly fish seems to tolerate other speciesfrom the same genus. It is an active fish that grazes on the algaein the decor and eats pieces of worms and mussels. Sometimes,however, it can refuse all food in its first few days in theaquarium. Size: 16 cm.Chaetodon aurigaOne of the best-known butterflies, the auriga ischaracterized by the adult's filamentous extension ofthe dorsal fin. Active and not prone to shyness, it iseasy to acclimatize. Feed it with living or frozen food,backed up by vegetable material if there are no algaeto graze on in the decor. Size: 14 cm.

Chaetodon capistratusAcclimatizing a four-eyebutterfly fish can becomplicated, as it normallyfeeds on the tentacles ofanemones and corals, but itsoon becomes easy to keep. Itis one of the rare speciesemanating from the tropicalAtlantic, where it is common.Size: 10 cm.CHAETODONTIDAE• Chaetodon lunulaEasy to acclimatize, theraccoon butterfly fishaccepts food of animal originbacked up with vegetablematerial. The black patches onthe young (dorsal area andrear) get bigger in adults oncethey have reached 7 or 8 cm.Size: 20 cm.Chaetodon miliarisIn its natural habitat, thelemon butterfly fish feeds onthe soft parts of corals. Incaptivity, it has to growaccustomed to small, live prey,then frozen ones (brineshrimps, tubifex worms).Size: 13 cm• Chaetodon collareThe Pakistani butterfly fish will tolerate fish of itsown species. Undemanding as regards diet, it acceptsboth frozen and live food and also feeds off algae inthe decor. It has a reputation for being easy to keep.Size: 17 cm.Chaetodon melanotusThere are few differences between the juveniles andadults of the black back butterfly fish. Thissomewhat nervous species appreciates brine shrimps,worms, and small pieces of mussel, as well as smallanemones of the Aiptasia genus that sometimes"spontaneously"appear in marine aquariums. Size:15-17 cm.• Chaetodon meyeriRarely found in the aquarium trade,Meyer's butterfly fish proves verydifficult to acclimatize as it feeds on coral.Even if it does accept substitute food, itis not unusual for it to die in captivity.Size: 15 cm.Chaetodon fasciatusThe Red Sea butterfly fish is consideredvery difficult to acclimatize, because itfeeds on anemone tentacles and the softparts of coral. This species can be confusedwith C. lunula. Size: 15-17 cm. •133

MARINE FISHChaetodon punctatofasciatusPlacid, little prone to aggression, but a vigorousswimmer, the dot-dash butterfly fish can acceptartificial food, after first adjusting to small animalprey. It is considered difficult to keep. Size: 10 cm.Chelmon rostratusThe elongation of the "beak" of thecopperband butterfly fish (morepronounced than that of theChaetodon genus) has evolvedto enable it to pick out foodfrom crevices in the coral. Thisrobust species swims slowly,except when it is alarmed. Itfeeds on small, live prey,notably crustaceans.Size: 17 cm.Chaetodon quadrimaculatusIn its natural habitat, the four-spot butterfly fishfeeds on corals or small anemones. It does acceptbrine shrimps and frozen food in captivity, making iteasier to keep. Size: 15 cm. •Chaetodon semilarvatusThe highly active masked butterfly fish searches outsmall prey near the substrate or in the algae, but it alsoswims in open water. Itsmaintenance can poseproblems, as it issometimes consideredto be delicate.Size: 20 cm.BUTTERFLY FISH COLORINGThe coloring of adults is often slightly different from thatof juveniles (size less than 5 cm), the black patch on therear of the dorsal fin sometimes disappearing in adults.It seems to act as a false eye (the real one being surrounded- and hidden - by a band or black patch) todeceive an enemy and surprise it by fleeing "in reverse."However, this theory has yet to be proven. Once the fishare fully grown, the juvenile bands can fade or disappearcompletely, although some, in contrast, can get bigger.ChaetodonocellatusThe placid spot-finbutterfly fish feedson small live andfrozen prey. It seemsto accept the presenceof other specimensfrom the same species.Size: 11-12 cm.134

CHAETODONTIDAEChaetodon vagabundusThe color of the young vagabond butterfly fish differs from thatof adults. This species is not given to shyness and is easy to feed,with live prey and vegetable supplements. Its acclimatization isrelatively smooth. Size: 1 5 cm.• Chaetodon striatusThe banded butterfly fish, like the C. capistratus and the Cocellatus, is native to the tropical Atlantic, while the otherbutterflies come from the Indo-Pacific region. It does not pose anyproblems once it has become used to small food items(crustaceans and anemones of the Aiptasia genus). Size: 15 cm.Forcipiger flavissimusThis is an easy species to acclimatize if it hasnot suffered too much during its importation.Not inclined to be aggressive (except againstmembers of its own species), the longnosebutterfly likes to have some hiding places. Itsdiet comprises mussels, tubifex worms, or fishflesh. Size: 15 cm. •Heniochus diphreutesThe first spokes of the fins of the Heniochius genusare elongated to a greater or lesser extent,depending on the species. The pennant butterflyfish is peaceful and easy to keep in a spacious tank.Small, live prey is its favorite food. Size: 20-25 cm.Heniochus intermediusThe background coloring of the black and white butterfly fishcan vary from white to yellow, except on the upper part of thebody. At night, when it can swim as actively as by day, it getsdarker. Size: 15 cm. •• Heniochus variusThe brown butterfly is distinguished by a protuberance betweenthe eye and the base of the dorsal fin, and by small tentaclesabove the eyes, which are more developed in the adult male.Size: 20 cm.135

MARINE FISHPOMACANTHIDAEThe Pomacanthids are reef-dwelling fish, although they can also be found in the rocky coastal areaswhere algae grow. They can sometimes be difficult to feed in captivity, although younger fish adaptmore easily to the food offered by aquarists. The Pomacanthids include both angelfish and dwarf angelfish.AngelfishAngelfish can be distinguished from butterfly fish by their protractile mouth and the presence of a spineat the base of the operculum.They are good swimmers and live alone or in small groups, close to shelters such as caves and coraloverhangs. As angelfish are highly territorial, they react badly to other members of their own species. Thecoloring of the juveniles gradually changes when they reach 8-10 cm (though this is not a general rule),and turns into that of the adults.Juveniles adapt more easily to captivity, but only one angelfish can be kept in a 500 liter tank.Their diet should consist of brine shrimps, mussels, and shrimps, along with cooked and choppedvegetable material.Chaetodonplus mesoleucusThe Singapore angelfish resembles aChaetodon; the young are very similar tothe adults. It is relatively easy toacclimatize if it is first fed live prey;it will then go on to acceptartificial food. Size: 17 cm. •• Chaetodonplus melanosomaThe black velvet angelfish respects otherspecies but chases members of its ownspecies off its territory. It is shy, a goodswimmer, and reckoned to be hardy. Itdevours large prey (nereis, also known asrag worms), but also eats tubifex wormsand brine shrimps, as well as grazing onalgae. Its skin is very sensitive to parasites.Size: 18 cm.136Euxiphipops xanthometoponYoung blueface angelfish acclimatizemore easily and can adopt a "cleaning"role with other fish. The adults,territorial and fearful, prefer small itemsof food, with some vegetable material.Size: 30-40 cm. •

POMACANTHIDAEHolacanthus ciliarisEven the juvenile queen angelfish are territorial, which can cause cohabitationproblems. They are easy to acclimatize, but demanding as regards the qualityof the water. Their diet comprises brine shrimp, sponges, algae, and mussels.Size: 20 cm.Holacanthus tricolorThe black patch on the juveniles of therock beauty angelfish enlarges as theygrow, until, by the time they are adults,it covers their entire body. Famous forbeing difficult to acclimatize, they feedon algae, brine shrimps, and small piecesof fish. Size: 15 cm. •Pomacanthus annularisAdult annularis angelfish can grow to 30cm. Their acclimatization is more difficultthan that of younger fish, below 7 or 8cm, which adapt to captivity better.These fish graze on the algae inthe decor but also appreciatemeat dishes: reddish foodseems to attract them, so it isworth trying to make them a"pate" in this color.PomacanthuschrysurusThe African angelfish is rarelyseen in aquariums. It needsvegetable components in itsdiet. When it is young, itsyellow-orange tail distinguishesit from the queen angelfish.Size: 20 cm.ANGELFISH JUVENILES' COLORING:HOW TO AVOID BEING TAKEN FOR AN INTRUDERThe coloring of angelfish juveniles (usually consisting of lines) is markedly different from that ofadults. This enables them to avoid being considered as intruders on their own patch, as the adultsrebuff fish of the same species, or those with similar coloring, in order to defend their territory andits resources: food and shelters. Both juveniles and adults share the same goal: to survive and perpetuatethe species.Queen angelfishJuvenile.Queen angelfishAdult. •• Euxiphipops navarchusSomewhat shy, the majesticangelfish likes to have hidingplaces. This does not prevent itfrom being an assiduous grazerof the decor's algae, although itdoes also accept small prey.Size: 20 cm.137

MARINE FISHPomacanthus imperatorThis is one of the most beautiful of all the angelfish. However, theterritoriality of the emperor angelfish can make it aggressivetowards other occupants of the tank. The juveniles display severalwhite circles against a blue background. This fish eats raw orcooked mussels, nereis, tubifex worms, fish flesh, shrimps, lettuce,and plenty of filamentous algae. Size: 20 cm.• Pomacanthus maculosusIn its natural environment, the purplemoon fish feeds on sponges and coral, so theseshould be avoided in its aquarium. In captivity it canadjust to eating small, live prey, and can then moveon to commercial food. Size: 30 cm.PomacanthusparuSub-adult.Pomacanthus paruActive by day and night, the Frenchangelfish will eat brine shrimps andmussels, and can sometimes be tamed.The adult resembles that of thePomacanthus arcuatus (gray angelfish), butthe ends of its scales glow with luminousyellow dots. The young of both speciescan similarly be confused; they aremarkedly different from the adults, withcurved yellow stripes against a blackbackground. Size: 25 cm. •• PomacanthussemicirculatusThe young have a dark blue bodyset off by fine white lines curvingtowards the rear. The territorialraccoon angelfish leaves itsshelter to eat nereis, raw orscalded mussels, shrimps, pieces offish, and tubifex worms, as well asalgae, lettuce, and riccia.Size: 40 cm.138

POMACANTHIDAEGenicanthuscaudovittatusThe Japanese swallow can bedistinguished from the G.lamarck by its vertical stripes.Shy, but often on the move, iteats the same as the G. lamarck:prey small enough to fit into itsmouth. Size: 20 cm.Genicanthus lamarckThe male has a yellow patch on theunderbelly and its pelvic fins are black. TheLamarck angelfish is sociable, despite itsshyness; it lives in small groups andtolerates other angelfish. Size: 20 cm.• Apolemichthys trimaculatusThe spine characterizing this family isblue, as is the mouth, and both standout against the yellow background.The black patch on the caudal fin ofthe young disappears in adults. Theflagfin angelfish appreciates avegetable component in its diet. It isa vigorous swimmer which needs alarge tank. Size: 25 cm.Apolemichthys xanthurusAn easy species to keep, the gray poma angelfish nibbles atalgae, but it also eats mussels, shrimps, and brine shrimps.Size: 10-13 cm.• Arusetta asfurThe asfur angel is an active swimmer, butlikes hiding among rocks. It feeds onmussels, lettuce, and animal foodstuffs.Sometimes confused with Pomacanthusmaculosus, it can be distinguished by itsyellow caudal fin, and the patch on itssides, also yellow, is further forward. Itgrows very slowly in an aquarium.Size: 20 cm.Pygoplites diacanthusSomewhat unassuming, the regal angelfish loves totake shelter in nooks and crannies. In the wild it feedson sponges; in an aquarium, it must be supplied withsmall food items: brine shrimps, mussels, and choppedshrimps. Size: 25 cm. •

MARINE FISHDwarf angelfish or CentropygesThese also belong to the Pomachantid family and share its characteristic spine. They are mainly native tothe Indo-Pacific region, where they frequent the coral reefs taking shelter in caves or under overhangs.Territorial; they can be aggressive with members of their own species, or with Centropyges with a similarcoloring. They are sociable with other fish and respect invertebrates. They are rarely longer than 12 cmand require an aquarium of at least 200 liters, equipped with places to hide. Their natural diet mainlyconsists of algae; in captivity, a vegetable diet of spinach and lettuce can be topped off with small, liveprey, especially crustaceans.Centropyge ferrugatusThe medium-sized rusty angel can be confusedwith other species. However, it is recognizablefrom the fine blue stripes on the dorsal andanal fins. The caudal fin is not convex.Size: 10 cm. •Centropyge bicolorIn nature, the peacefulbicolor angel live in groups,but this is not possible incaptivity, except in very largeaquariums. It is sometimesdifficult to keep in a tank andhas a reputation for being afussy eater. Its basic dietconsists of brine shrimps,tubifex worms, and choppedmussels. Size: 10 cm.Centropyge acanthopsThis is a small species, relativelyeasy to keep, but rarely foundin the aquarium trade. Theflame backangelfish likeshideaways andfeeds on algaeand smallinvertebrates. Insome specimens,the eye issurrounded bya blue circle.Size: 7 cm.Centropyge eibliEibl's angelfish, aggressive towards allthe other species in the genus, is easy tokeep in captivity. Its vegetable diet can becomplemented by small invertebrates.Size: 12 cm. •

POMACANTHIDAECentropyge loriculusOne of the most beautiful dwarf angels, the flame angelfishappreciates hiding places in an aquarium. It feeds on algae andbrine shrimps, but may also accept commercial food. Size: 7 cm.Centropyge heraldiThe yellow angelfish resembles the lemonpeelangel, although it does not have the blue marks onthe eye, operculum, and fins. This delicate species israrely imported. Size: 10 cm.• Centropyge potteriThe Potter's angelfish is placid and accepts a wide range offood. Nevertheless, it is sometimes considered delicate for anaquarium. Size: 10 cm.• Centropyge flavissimusThe eye of the lemonpeel angelfish is framed by a blue circle;the juvenile has an ocellus (eyelike spot) in the middle of each side.It accepts small items of food, but keeping it in captivity has itscomplications. This species is fragile and is rarely imported.Size: 11 cm.Centropyge vrolikiThis is one of the largest fish in this genus:the half-black angelfish acclimatizes welland flourishes in captivity, accepting bothlive and dead prey. It is particularlyaggressive towards other dwarf angelfishwhen it is deprived of sufficient space.Size: 13 cm. •141

MARINE FISHPOMACENTRIDAEThese are undoubtedly the most popular marine fish found in aquariums. Modest in size and brightlycolored, they are active and easy to keep. Most species reproduce without any problem. These fishare recommended for beginners, who can put them in a tank with a minimum of 200 liters of water.They feed on small animal prey, both live and dead.Clownfish or AmphiprionsThese fish owe their name to their coloring. Severalspecies are commercially available nowadays, oftenwith their associated sea anemone, because theirlife is generally intertwined with this invertebrate,which offers them protection. In return, theanemones can take advantage of the clowns'leftover food, although this is not always the case,and they can also live without the company of theirtenants. The Amphiprions are not affected by theaction of the anemone's venom; they protectthemselves by progressively rubbing themselves init, which grants them a kind of immunity. If aclownfish is separated from its anemone for anylength of time, on its return it has to graduallyrehabituate itself.Anemones also play an important role in thereproduction of Pomacentrids for, without them,they breed less often. The fish mark out a territory(around 0.25 m-) close to the anemones, lay theireggs on a support, and defend the site. The parents,Amphiprion bicinctusThe two-banded clownfish is among thebiggest of the genus. It is a robust species,which is sometimes aggressive towardsother Amphiprions. Size: 15 cm.which stay faithful to each other - the malesare generally monogamous - can reproduceevery 2-4 weeks. Clownfish, at first males, laterbecome females, which are then bigger. Feedingthem in captivity does not present any problems:they like small live and frozen prey, mussels, andchopped shrimps, and they sometimes acceptcommercial artificial food.Amphiprion akallopisosEasy to keep in captivity, the pink skunkclownfish can live in small groups. Itis sometimes dominated by otherspecies. It lays its eggs close to ananemone. Size: 10 cm.• Amphiprion ephippiumTerritorial and sometimes aggressive, the redsaddle clownfish lives alone or in couples.It lays eggs without any problems and canlive without an anemone. Size: 15 cm.

Premnas biaculeatusThe maroon clownfish is distinguishedfrom the Amphiprion genus by the spineon its operculum. It is quite aggressive,towards both its own species andAmphiprions. Size: 13-15 cm.Amphiprion frenatusThe juvenile's small white bandin the middle of its sidesdisappears in adulthood. Highlyterritorial, the tomatoclownfish lives in couples; itreproduces easily. Size: 15 cm. •POMACENTRIDAE• Amphiprion perideraionIt is best not to keep more than one coupleof this small species, without any otherclownfish. The dorsal and anal fins of themale skunk clownfish display a fineorange band; the females are white ortranslucent. Size: 9 cm.• Amphiprion sebaeSeba's clownfish, easy to keep in anaquarium, is one of the biggestAmphiprion species, as the female growso 12 cm. An anemone housesa single couple, sometimes withthe fry.Amphiprion ocellarisSeveral couples can live in the same anemone, if it is big enough. Easy to keep,the ocellaris clownfish is nevertheless fragile in its acclimatization period (1-3months); after that, it is highly robust. It lays eggswithout problems and accepts artificial food. It issometimes confused with the true clownfish(Amphiprion percula), but its white bands arefringed withblack.Size: 11 cm.Amphiprion clarkiiClark's clownfish lives incouples, occupying severaldifferent anemones andstraying some distance fromthem. It is one of the easiestto acclimatize. The male isdistinguished by its yellowcaudal fin (white in thefemale). Size: 15 cm.143

MARINE FISHANEMONES ASSOCIATED WITH CLOWNFISHEven though some clownfish can live without anemones, in captivity it is best to provide them with one - but not just any one. In fact,the associations concern exact species, although there may be confusion because the scientific names of anemones changed some 10years ago. Some anemones can house several species of clownfish, others are more exclusive.144

DAMSELSDamsels are pretty fish that are easy to raise, and some livein association with anemones. They adapt well to captivityand often accept artificial food (though live prey, mussels,and ground shrimps are clear favorites); they lay eggs quiteeasily. With these characteristics in mind, and not forgettingtheir modest price, damsels are recommended for aquaristsmaking their first venture into sea water.POMACENTRIDAE• Pomacentrus coelestisThe electric blue damsel can live in groups in a largetank. In a smaller aquarium it is wise to keep only asingle specimen. Size: 8 cm.• Glyphidodontops cyaneusLike the other species known as damsels, this is oneof the least expensive of aquarium marine fishes. Theblue damsel (syn. Chrysiptera cyanea) is territorialand can sometimes be aggressive. It acceptscommercial foods. Size: 8 cm.Abudefduf saxatilisThis is more aggressive than the other damsels. Thesergeant-major can live to an age of 5 years or morein captivity. It eats mainly brine shrimps, mussels,and chopped shrimps. Size: 15-17 cm.DAMSELS FOR BEGINNERSNovices are advised to start with the "blue damsels" group. Chromis caerulea(the blue-green damsel) is active and lives in groups, sometimes dominatedby the males. It accepts artificial food. Chrysiptera parasema (azure damsel, syn.Glyphidodontops hemicyaneus) is a robust species which lays eggsin captivity. The female can sometimes lay more than 200 eggs,and is then ejectedfrom the nest by themale, which takes onthe task of guardingit. Hatching occursafter 1 week. This fishwill accept commercialfood.Chromis caeruleaChrysipteraparasema145

MARINE FISHCLARIFICATIONOccasional variations in color and name changes can lead toconfusions in this group, especially in the species that are predominantlyblue.The latter includes a blue-green damsel, while the blue damselscan present yellow coloring on the tail and belly, although thisvaries from one specimen to another. They are all easy to acclimatizeand feed, and they reproduce in captivity - all these factorsendear them to beginners.The second group of damsels is distinguished by its verticalblack bands (genus Dascyllus', 6 or 7 species are currentlyimported).The third group covers the Abudefduf genus - including thespecies sometimes known as "devils" - which are less commonin aquariums.Dascyllus trimaculatusThe young domino damsels livein groups, while the adultsgradually isolate themselves.The white spots disappear inolder fishes. Theirreproduction is easy; themale watches over the eggs.Size: 14 cm. •Dascyllus aruanusThe three-stripe damsel does not exceed 8 cm in length as anadult and prefers to live in isolation; the young live in groups. Aclosely related species, D. melanurus (black-tailed damsel), isdistinguished by a vertical black band on the tip of the caudal fin.LABRIDAEThe Labrids constitute one of the major fish families (several hundred species dividedamong 70 genera). These highly active, colored fish with fusiform (tapering at eachend) bodies often live alone. Some species bury themselves in the sediment at night, andthis must be taken into account when planning the aquarium: provide them with a sandybed. Their sturdy teeth allow them to feed on invertebrates (which must, therefore, bekept away from them). In captivity they accept live prey, but will become accustomedto deep-frozen (sometimes commercial) food. The coloring of the juveniles is oftenvery different from that of the adults.Coris angulataThe Coris clownwrasse grows to1 m in the wild butdoes not exceed 30cm in an aquarium.The juveniles arecharacterized by theirlarge, red dorsalpatches, which fadewhen they reach alength of 10-15 cm.The adults are auniform brownblack.Aggressive towards other wrasses, this fish buries itself atnight, or when in danger. •Coris formosaThe adult Formosa wrasses are dark brownwith dark patches; the paler juveniles have bigwhite spots. Size: 20 cm.146

Gomphosus coeruleusThe birdmouth wrasse can live in couples,but two males will not tolerate each other.it is easy to keep and its feeding poses nospecial problems. The adult male is greenblue,the female brown-purple. Size: 30 cmmale), 20 cm (female). •LABRIDAETHE FALSE CLEANER (ASPIDONTUS TAENIATUS)This is not a Labrid - in fact, it belongs to the Blenniid family -but it closely resembles the true cleaner, although the positionof its mouth is different (it is terminal in the true version). Ittakes advantage of this resemblance by tricking fish into gettingcleaned and then tearing off pieces of their skin, or even theirbranchiae. False cleaners are raised in specific aquariums andfed on crustaceans. On very rare occasions they attack fishbelonging to the Labrid family. Size: 10-12 cm.Labroides dimidiatusThis wrasse is "cleaning" anAcanthurus leucosternon.Labroides dimidiatusThe cleaner wrasse, with a reputation forbeing difficult to acclimatize, lives incouples as an adult. It feeds on live preyand it has a highly distinctive habit: it"cleans" other fish. It puts on a show in aspecific part of the tank to attract them,and it then frees them of their externalparasites or pieces of dead skin. Whenthere are no males available, a female canchange sex. Size: 10 cm.• Coris gaimardThe adult red coris wrassessport bright blue dots on abrown-red background; theyoung are red with white dorsalpatches which gradually fadewith age. This fish buries itself inthe sand, although it is a goodswimmer. It feeds on mussels,shrimps, worms, and artificialfood. Size: 20 cm.147

MARINE FISHBodianus mesothoraxThe young are brown-black with darkpatches on the fins that disappear in thebicolor adult. The harpfishswims continuously, and itmust therefore be given alarge space with room tomove about, althoughthe aquarium must alsoprovide it with shelters.The adults do nottolerate members of theirown species. Size: 20 cm. •Bodianus rufusThere is barely any difference between theyoung and the adults, which are somewhataggressive. This Spanish hogfish hascarnivorous tastes. Size: 25 cm.Lienardella fasciataThe Harlequin tusk wrasse, aggressiveeven toward bigger fish, likes eatingmollusks, worms, and crustaceans, and itneeds shelters. Size: 15 cm. •• Thalassoma lunareThe lunar wrasse is aggressive towardsother members of its own species. It iseasy to acclimatize, although it requireslarge open spaces in which it can swimfreely. Size: 20 cm.Anampses chrysocephalusThe active red tail anampsesspends its time looking forfood of animal origin. Itburies itself in the sand andneeds hiding places. Thecoloring of the youngresembles that of the femaleshown in the photo, but themales are very different.Size: 20 cm.MURENIDAE (MURENAS)These usually nocturnal fish stalk small prey.They camouflage themselves in rocks andcrevices, with only their head sticking out. Anaquarist must be careful, because a murena's bitecan be dangerous.148Echidna nebulosaThe snowflake murena is anattractive species which sometimesmakes an appearance by day,especially at mealtimes. It can livefor quite a long time. Its tail canalso be very long, so plan on a bigtank. Size: 90 cm. •

SIGANIDAEThese are distinguished by spiny spokes which secrete a venomoussubstance. A prick is painful for an aquarist, although not as muchas one caused by a lionfish (but it is still advisable to consult adoctor). These small-mouthed fish are herbivorous.ZANCLIDAESiganusSeveral of these species are commercially available. Thepeaceful rabbitfish graze algae in the decor but alsoaccept small pieces of animal food. When they arefrightened they take refuge in thehiding places that areindispensable for thesefishes. Size: 20 cm. •• Lo vulpinusHardy and easy to acclimatize, thefoxface feeds on small, live prey andvegetable material. It will accept musselpieces but what it really relishes is groundspinach. It is placid but active, and needsroom to swim, along with somewhere tohide. Size: 20 cm.ZANCLIDAEThe Zanchlids have a very compact body: one of the spokes of the dorsal fin is extended in a finefilament. Considered fragile and delicate, they feed on small, live prey and can sometimes attackinvertebrates (corals, worms). Even if their form suggests otherwise, they are closely related to theAcanthurids, although, unlike these, they do not have a spine on the caudal peduncle. These fish aresensitive to chemical treatments and can diesuddenly, without any apparent reason. Intheir native habitat (the Indo-Pacific region),they are respected, and even sometimesvenerated, by local fishermen, who oftenreturn them to the sea.Zanclus canescensThe Moorish idol normally feedson algae and sponges. In captivity itmust be given a wide range of foodso that it can make its own choice.It does not tolerate the presence ofother Zanclids. Z. cornutus isconsidered a closely related species,but is distinguished by the absenceof small spines in front of the eyes.Size: 25 cm.149

MARINE FISHACANTHURIDAE (TANGS)Native to the tropical waters of the Indian and Pacific oceans, the tangs are less common in the Atlanticocean. An upright spine on the caudal peduncle has earned them the alternative name of surgeonfish,as this spine resembles a scalpel. It plays a defensive role and can represent a danger for the aquarist.Despite their squat bodies, which seem to have been squashed sideways, they are good swimmers, andthey live in groups in a natural setting. They feed on algae and small prey which fit into their mouths.These fish are active and require a tank of at least 300 liters, with only one tang, because in such a limitedspace they do not get along with each other. It is also advisable not to put any invertebrates into theaquarium. Tangs feed on brine shrimps or other live prey, but they also require a vegetable complement.The water must be well filtered and stirred, with fairly bright lighting,to favor the growth of algae.The young are easier to acclimatize. Their reproduction, which,in their natural environment, seems to be connected with thelunar cycle, has never been observed in an aquarium.Acanthurus achillesA very delicate species to keep, the Achilles tang appreciatespartial (but small) changes of water on a regular basis. It acceptsvegetable foodstuffs and small animal prey. Size: 15-18 cm. •• Acanthurus japonicusThe powder brown tang is a good swimmer. It keenly grazes thealgae on the decor, but also accepts small prey. It is very delicateto keep in captivity. Size: 18 cm.Acanthurus lineatusThis is a fairly easy species to keep in captivity, if it is supplied withvegetable foodstuffs. A good swimmer, the clown tang behavesextremely aggressively towards other tangs. Size: 18-20 cm. •Acanthurus leucosternon •The powder blue tang appreciates hidingplaces and changes of water. Difficult toacclimatize, it can however accept commercial foodstuffs if theyare predominantly vegetable. Size: 15 cm.150

ACANTHURIDAEAcanthurus sohalThe sohal tang is one of the most beautiful of the Acanthurids. Itcan accept artificial vegetable food, but it prefers to feed on brineshrimps and ground mussels. Its territorial behavior sometimesmakes it aggressive. Size: 25 cm.Naso brevirostrisYoung longnose unicorn fish do not have a horn. A relatedspecies, N. unicornis, only has a hump on its forehead. These twospecies are vigorous swimmers and mainly feed on algae; theadults are more carnivorous than the young. Size: 25-30 cm. • • Naso lituratusThe smooth-headed unicorn fish is a relatively easy species tokeep. Although generally placid, they can become aggressive ifthey are upset. The adults in this species have fineextensions to the tips of the caudal fin, while thejuveniles have white patches. Size: 25 cm.Paracanthurus hepatus •The blue coloring of the young turns gray on their belly and backonce they reach adulthood. Somewhat unobtrusive, the hippotang likes having hiding places. Size: 18 cm• Zebra so ma flavescensThe anal and dorsal fins of the zebrasomas are more developedthan those of other tangs. These timid species must be provided.vith shelters. The coloring of the yellow tang varies according tots geographical origins. Size: 18 cm.Zebrasoma veliferumWhen the sailfin tang is in motion, this beautiful swimmer tucksits fins along its body, although it does open them to "impress"other members of the same species and to chase them off itsterritory (the yellow tang does the same). Size: 30 cm. •151

MARINE FISHSCORPAENIDAE (LIONFISH)Lionfish are not only stunning to look at, but they can alsoconstitute a real danger for an aquarist: some of their spinyspokes emit a venom similar to that of certain snakes. They are placidand majestic fish, easy to keep in an aquarium of at least 300 liters.The tank must be furnished with elaborate and convoluted decor,complete with grottoes and overhangs: lionfish swim through themflat or at an angle. Their large mouth is equal to their voracity: they devour live prey, often small fish (takecare with their roommates!). Nevertheless, these remain amongst the most deirable subjects for theamateur aquarist and repay without any doubt any amount of trouble.WHAT TO DO IFYOU ARE STUNGConsult a doctor immediately. The veryintense pain increases for 20 minutes,reaches a peak, and gradually subsidesover a period of 4-24 hours. Bleed thewound and immerse it in the hottestwater possible to partially inhibitthe action of the venom.Obviously, the best idea isto avoid getting stung;take care when puttingyour hand into the tankand wear protectivegloves that are waterimpermeable.Pterois volitansThe volitan lionfish is the one most oftenfound in the aquarium trade. It getsaccustomed to dead foodstuffs. Themembrane linking the spokes of thepectoral fins runs to the rear end of theirbody, which is not the case with the otherspecies of the Pterois genus, where therear is unencumbered.Size: 35 cm• Pterois antennataThe antenna lionfish has four dark bandson its head. A close relative, P. sphex, hasless intense coloring. The latter is hard tofind in Europe, but is frequently importedinto the United States. Size: 20 cm.Pterois radiataTwo white horizontal bands on thecaudal peduncle distinguish theradiata lionfish from the other species.Easy to keep, it getsused to eating deadprey. Size: 25 cm. •Dendrochirus zebraThe dwarf lionfish does not grow longer than 15 cm, in contrastto the Pterois. It is also distinguished by the absence of amembrane between the spokes of the pectoral fins.Size: 15 cm.152

BALISTIDAE (TRIGGERS)BALISTIDAETriggers live in reef areas where the water is in constant movement, so you must plan a large aquariumfor them (at least 400 liters) with highly agitated and well-oxygenated water. Their jaws and teethallow them to graze on coral, crabs, and mollusks. In captivity they accept animal food, such as smallmollusks (cockles, mussels), complete with their shells. They are fairly aggressive and must be kept singly,away from small fish and invertebrates. One of the distinguishing features of this family of marine fish isits ability to stick out the first spoke of its dorsal fin, and then block it with the second one (explainingtheir alternative name of crossbowmen).• Balistoides conspicillumThe clown trigger is not only voracious -it is also fast, usually reaching any foodbefore other fish. It is not slow torearrange the decor, either, although itis easy to domesticate. However, it is bestto acclimatize it before it measures morethan 10 cm. Size: 25 cm.• Balistapus undulatusThe undulated trigger fish is so resistant that it can survive forover 10 years in an aquarium. It is easy to acclimatize and keep,although it is prone to knocking over bits of decor. Size: 20 cm.Balistes vetulaThe queen trigger fish, native to the tropical Atlantic - theothers come from the Indo-Pacific region - is one of the mostplacid. It is easy to acclimatize and grows quickly - sometimes upto 50 cm. Size: 30-50 cm.• Rhinecanthus aculeatusIts common name, the Picasso trigger fish, comes from itsdistinctive coloring. It defends its territory fiercely. Some relatedspecies (R. asasi, R. rectangulus, R. verrucosus) are sometimescommercially available, often under the same name. Size: 20 cm.153

MARINE FISHOdonus nigerThe blue trigger fish can live for more than 10 years.If you have a couple, reproduction may be possible ina very large aquarium, in a nest dug into the sand.Size: 20 cm. •Pseudobalistes fuscusThe coloring of juveniles is paler than thatof adults. The blue line trigger is fairlyaggressive but can get to know its owner.It sometimes looks for its food by"spitting" water to lift up the sand.Size: 35 cm.Xanthichthys auromarginatus •The magnificent blue throat trigger requires a largetank, with shelters where it can take refuge at night. It isaggressive towards both fish smaller than itself andmembers of its own species. Size: 30 cm.HAEMULIDAE - NEMIPTERIDAEThe Haemulids (grunts or pork fish) make sounds bygrinding their teeth, with the swim bladder acting asa resonator. Rarely found in aquariums, they arenevertheless robust.The Nemipterids live near reefs and are vigorous freeswimmers.They feed on small prey captured on theirjourneys or in the sediment.Anisotremusvirginicus (Haemulidae)The pork fish lives in schoolswhen it is young. The adultsgradually become loners asthey grow older, and theircoloring becomes brighter. Incaptivity, they can be fedsmall animal prey, dead oralive. Size: 30 cm.• Symphorichthysspilurus (Nemipterid)The large long fin or blue andgold snapper requires a lot ofwater to be able to move aroundfreely. It prefers to live in calmareas and accepts a wide rangeof food. This brightly colored fishis rarely found in the aquariumtrade. Size: 30 cm.

OSTRACIONTIDAE (BOXFISH)Their body form renders their swimming clumsy, but these fish arenevertheless highly active. Their skin is fragile and very sensitiveto parasites. In an aquarium it is best to keep only one specimen,which can sometimes be "tamed" to eat out of your hand. Their smallmouth means that they can only eat tiny prey and algae. If they arealarmed, boxfish secrete a toxic substance, with deadly effects forother fish in the vicinity.PLOTOSIDAE• Lactoria cornutaThe form of the long horn cowfish, with"horns" on its head, is highly unusual. It isa placid species, easy to feed with smalllive or dead prey. Size: 10 to 15 cm.• Ostracion meleagrisThe magnificent spotted boxfish isconsidered tough, although it only actsaggressively towards its own species. Itmust be supplied with animal foodstuffsand a vegetable complement. The coloringvaries according to the fish's age and sex.Size: 15 cm.Ostracion cubicusEasy to keep, the yellowboxfish is aggressive towardsall other boxfish. It swimsslowly in and out of the decor,hiding in a shelter whendisturbed. Size: 25 cm. •PLOTOSIDAEThis is one of the few catfish families that live in the sea. Their anal and dorsal fins are long, and thepectoral fins have a spiny spoke connected to a venomous gland. The barbels around the mouth havea tactile function and help to detect food.Their elongated body enables them toweave their way skilfully through naturalobstacles in their path.Plotosus lineatusThe young live in shoals where they form a ball, withtheir heads facing outwards, when they are faced withdanger; the adults are more solitary. They feed onanimal foodstuffs or small prey appropriate to the sizeof their mouth. This fish has a reputation for beingfragile and an avid consumer of oxygen. Size: 30 cm.155

MARINE FISHCANTHIGASTERThis is a small family, closely related to the Tetraodontids; like them, they are commonly known aspuffers because they can blow up their bodies. Easy to keep, they feed on crustaceans and mollusks.They are aggressive towards members of their own species, but are placid in the company of other fish.Canthigaster margaritatusThe peacock puffer is distinguished by a black patch framed inpale blue. It adapts well to an aquarium, though its animal foodsupply must be complemented by vegetable material. Size: 12 cm.Canthigaster valentiniThe Valentini puffer, which can be recognized by its twoblack bands, is less common in the aquarium trade than thepeacock. If Canthigaster are not fed properly they may startnibbling at the fins of other fish. Size: 20 cm. •DIODONTIDAE (PORCUPINE FISH)Their skin is dotted with spines, which stick out in response to danger, and the effect is enhanced by thefish puffing out its body to impress its foe. Porcupine fish are considered easy to acclimatize, but theydo not tolerate members of their own species. They feedon mussels and small shellfish - complete with shell -which they can munch thanks to their strong teeth.• Diodon hystrixIt is best not to put invertebrates in atank with the common porcupine fishas there is a chance it might find themappetizing. It may eat shrimps, small crabs,or mussels out of your hand - but watchout for its teeth! Sadly, this fish issometimes sold, dried and bloated, as adecorative object, or even as a lampshade!It can grow to 90 cm in the wild.156

TETRAODONTIDAE (PUFFERS)SYNGNATHIDAETheir skin is highly sensitive as they have no scales, but they can puff themselves up with air and waterin the event of any danger. Their teeth, joined together like a parrot's beak, enable them to breakcorals and the shells of crustaceans. Do not be tempted to feed them out of your hand, to avoid gettingbitten. They are easy to keep in captivity, but it is best to keep them singly as they cannot stand otherpuffers, and invertebrates should obviously be ruled out.Arothron nigropunctatusThe gray color of the dogface or hushpuppygets darker with age. It can get soaccustomed to an aquarist that it will evenallow him or her to scratch its back! There areother puffers on the market, particularly themeleagris puffer, A. meleagris. Size: 20 cmArothron citrinellusThe yellow puffer is easy to acclimatize. Itis active and needs space for swimming,along with hiding places in which toshelter. It appreciates a vegetablecomplement to its animal food.Size: 20-25 cm.Arothron hispidusThe stars and stripes puffer is not only aggressive towards otherpuffers but can also turn against smaller species if the aquarium istoo small. It is easy to acclimatize and can sometimes be tamed.Size: 50 cm. •SYNGNATHIDAEThis family includes both temperateand tropical seahorses.They are bad swimmersand feed, in motion, on smallplanktonic crustaceans.In the same family, relatedspecies, known as sea needles,are sometimes available. Theyare easy to keep in captivity withthe same diet, and are particularlysuited to aquariums forinvertebrates.Hippocampus kudaThe yellow seahorse is, as its namesuggests, usually yellow, but its coloringgets darker in poor environmentalconditions. It stays in a vertical position,with its tail serving to cling on to the decor(which must be free of Coelenterates). Incaptivity, it feeds on brine shrimps or othersmall, live prey. Reproduction may bepossible in captivity: the male incubates theeggs in its ventral pocket. Size: 15 cm.157

MARINE FISHGRAMMIDAEKnown as dwarf bass, due to their similarity tothe true bass, the Grammids are small andcolorful. They are ideal fish to include in anaquarium with invertebrates.Gramma loretoThe royal gramma takes refuge in hiding places, often with itshead inside. As an adult it lives alone and can be aggressivetowards members of its own species. It feeds on brine shrimps,pieces of mussel, or small fish. Size: 8 cm. •PSEUDOCHROMISThese are solitary, active fish which quickly go into hiding when they are disturbed. They must cohabitwith species of the same size, in a decor furnished with hiding places.Pseudochromis diademaThis resembles the royal gramma, with which it can cohabit -which is not the case with members of its own species. It flaunts agolden yellow coloring set off by purple. It feeds on small, live preyand pieces of mussel. This fish is recommended for invertebrateaquariums with enough space for it to hide. Size: 7 cm.PLESIOPIDAEThe Plesiopids, related to the Pseudochromis, can be distinguished by their large dorsal and ventralfins. This family of coral-dwellers numbers only a few species, of which only one is found in theaquarium trade. They live in reefs, where they hide in the crevices. This has led them to be consideredas somewhat rare, although there areprobably more of them than is generallyCalloplesiops altivelisThe marine beta grouper has a majestic bearing, inkeeping with its placid, rather shy nature. It cohabitswith species of the same size and feeds on live prey,ground mussels, and small fish. In aquariums, it seeksout dark nooks and crannies. Its eyesight isexceptional. Size: 15-18 cm. •158

EPHIPPIDAE (BATFISH)CALLIONYMIDAEThe dorsal and anal fins of young batfish are disproportionatelylarge, making their body higher than it is long. As theyreach adulthood, they gradually adopt a circular form. Slow andeasy to acclimatize, they are, however, aggressive toward otherbatfish. They grow very quickly, with some adults reachingheights of 75 cm and weights of around 25 kg.Platax pinnatusThe red batfish must be kept with peaceful species if itsfins are to remain intact. Its diet consists of small live orfrozen prey. Some related species are also widely available.APOGONIDAE (CARDINALS)The cardinals, diminutive and brightly colored, preferdarkness (as their large eyes suggest). They live ingroups and are not too keen on active fish. The maleincubates the eggs in its mouth (rare among marine fish).1 latching is possible in captivity, but feeding the fry bringsnew problems.Sphaeramia nematopteraThe pajama cardinal can live in groups and respectsinvertebrates. It is sometimes confused with the closelyrelated species 5. orbicularis, which is alsocommercially available. They must both be fed withsmall animal foodstuffs. Size: 10 cm. •CALLIONYMIDAE (DRAGONETTES)Their life is inextricably linked with the bed, where they look for the live prey that make up their diet.They are usually found in fairly shallow water. They can raise themselves slightly by supportingthemselves on their ventral fins. Their cylindrical body is covered by a scaleless skin.Synchiropus splendidusThe blue mandarin accepts small morsels of fish ormussels, which it will only take from the bed. Evenwhen raised in couples, they will fight to the death,especially if the tank is too small. These fish are wellsuited to invertebrate aquariums. Size: 10 cm.159

MARINE FISHMONACANTHIDAE (FILE FISH)These are somewhat more pacific than the triggers, to which theyare scientifically related. These rather timid fish feed on verysmall prey (brine shrimps, pieces of mussel).• Oxymonacanthus longirostrisThe orange-spotted file fish likes nooksand crannies but is also an active swimmer.It can live in groups and is recommendedfor invertebrate aquariums. Size: 10 cm.Chaetoderma penicilligrumThe tassled file fish stands out due to theprotuberances on its skin. It relishes algae, even morethan live prey. The adults are loners and can attacksome invertebrates. Size: 11-25 cm.OPISTOGNATHIDAEThis family digs vertical burrows in the sand,and barely venture out, hiding themselvescompletely if there is any danger. Their largemobile eyes enable them to detect their small prey.CIRRHITIDAEThese generally live in shallow coastal waters. Incaptivity, they prefer to share with peacefulfish that do not penetrate into their strictlydemarcated territory.Oxycirrhites typusThe longnose hawk, a delicate species to keep, is suitable for aninvertebrate tank. It accepts brine shrimps, then small animalfoodstuffs appropriate to the size of its mouth. It is rarely capturedor imported. Size: 10 cm.• Opistognathus aurifronsThe pearly jawfish, an easy fish to keep, is recommended forinvertebrate aquariums. It must have at least 15 cm of sediment. Itfeeds on mussels, shrimps, and fish flesh, but all its food must bebroken up into small pieces. Reproduction is possible, but is bestleft to experienced fishkeepers. Size: 10-15 cm.160

GOBIIDAE (GOBIES)Gobies live in coastal waters. When they areaway from their shelters, they resist themovement of the water by clinging on to rocks withtheir pelvic fins, which are turned into suckers(although there are exceptions to this). They areeasy to raise and feed on small, live prey.BLENNIIDAELythrypnus dalliThe Catalina goby, a small species native toCalifornia, can be distinguished by its verticalblue bands. It lives in harmony withinvertebrates. Size: 4 cm. •Nemateleotris magnificaThe fire goby, native to the Indo-Pacificregion, more than lives up to its Latin nameof magnifica. It adapts well to captivity butremains somewhat timid, and so it must bekept with placid species, or in aninvertebrate tank. It accepts artificial food.Several species from the same genus, withsimilar vivid coloring, are sometimes foundon the market. Size: 10 cm.BLENNIIDAE (BLENNIES)Blennies live in rocky coastal spots, or in sheltered reef areas. These robust little fish, easy to raise, arewell suited to a tank for marine invertebrates. They are characterized by their abundant mucus andtheir often bright coloring. Blennies are not common in the aquarium trade, although it is possible to findsome species belonging to the Ecsenius genus.Ecsenius sp.The blennie defends its territory, so thepresence of other fish from the same familyis not advisable. It moves around, butoften remains stationary to observe itssurroundings, or hides among the decor. Itfeeds on algae taken from the decor andalso accepts small animal foodstuffs.Size: 8-10 cm.161

THE MAIN INVERTEBRATE GROUPSThe invertebrates, as their name indicates, have no backbone. Their body is soft, but it is protected onthe outside, by a carapace in the case of the crustaceans, or by a shell in mollusks, or it is supportedby an internal calcareous skeleton, as in corals.Although they are considered less evolved animals than the vertebrates - the group to which fish belong- invertebrates sometimes adapt in surprising ways to ensure their survival. The crustaceans, for example,can walk or swim to look for food or flee an enemy, while corals and anemones unfurl to capturemicroparticles, such as plankton, in open water, or retract to escape their predators.SPONGESCOELENTERATESThese animals, slightly more evolved than sponges, werealso classed as vegetables for many years; even now theterm animal-flowers is used to describe them. TheCoelenterates comprise medusas ("jellyfish") - rarely seen inaquariums, apart from a few public ones - and theAnthozoa, which include anemones and corals, some ofwhich are found in aquariums.Up until the 19th century, naturalists hesitated when classifyingsponges: animal or vegetable? It must be admitted,however, that their field of research was extensive, as thereare around 10,000 species of sponges.These very old animals were among the first to appear onearth or, more exactly, in the sea. Freshwater species are rareand are not found in aquariums, but some marine speciescan be kept in captivity.WORMSWorms are barely evolved soft-bodiedanimals. They are more common inaquariums as live food than as residents,but are never found in freshwateraquariums.A few specific species can be kept incaptivity in sea water. They live in atube and are often sedentary. The coloringof worms can vary enormously,but they are usually blue or purple,flecked with white, and almost alwaysbicolor.

MOLLUSKSTheir limp body is protected by a shell, which has two parts- these are the bivalves - or a single part - as in the case of:he gastropods.The bivalves half-open their shell - formed, as their namesuggests, by two valves - to filter water. In this way theyabsorb oxygen and capture food particles, particularly vegetalplankton. Keeping them in an aquarium does not, therefore,pose any problems.The gastropods, related to land snails, have a spiraled shellwhich varies in shape, according to the species. An organ inthe mouth in the form of a grater, the radula, allows themto graze micro-algae on the decor, glass sides, or plants. Thiscleaning function constitutes their main attraction for aquarists.Do not, however, expect them to gobble up all yourunwanted algae, as they play a more preventive role torestrict their untimely growth. They can sometimes attackthe leaves of plants or eat a surplus of the food intended forfish. Some species are carnivorous.CRUSTACEANSThe crustaceans' bodies are protected by an articulatedcarapace. The animal abandons its carapace when itbecomes too small due to body growth; this phenomenon iscalled the molt. The crustacean is particularly vulnerable toattacks from predators during the formation of the newcarapace. The crustaceans found in aquariums belong to thedecapod group, which have five pairs of walking legs, thefirst of which are used as pincers, with varying degrees ofstrength. The two pairs of antennae, highly developed inshrimps, play a tactile and sensory role. Crustaceans are carnivorous,and can feed on live or dead prey - they are notdifficult to feed in an aquarium.ECHINODERMSThese possess a symmetry based on five, which is extremelyrare in nature, as most animals have a binary symmetry,meaning that, if they are cut down the middle, two identicalparts can be observed. This is not possible with echinoderms,because they have to be cut into five sections toobtain identical pieces. Echinoderm means spiny skin: this ishighly appropriate in the case of sea urchins, less so in relationto the rough starfish. Generally speaking, echinodermswill not survive for long outside water. They are found onlyin sea water.

FRESHWATER INVERTEBRATESAlthough freshwater invertebrates play a significant ecological rolein their natural habitat, they are not popular with aquarists, andthis is a great shame. They are represented by two main groups:the mollusks and the crustaceans.• Ampullaria sp.,like this goldenvariety, are one ofthe most effectivegastropods againstalgae.MOLLUSKSBivalves commonly known as freshwatermussels can be found in some tropicalwaters. Although they differ as regards theiranatomy, they are in fact distant cousins ofthe mussels on our coasts. They live buried,or partially buried, in the sediment. They eatby filtering micro-algae or vegetal planktondissolved in the water. This can be a usefulattribute in an aquarium, as it helps containthe proliferation of this type of algae. Onthe other hand, if there is not enough food,they will eventually die - which is notalways noticeable at first, and thereforeentails a risk of pollutionfrom their deadbodies lingering in thewater. Bivalves thereforehave a somewhatlimited appeal to fishkeepers,especially asfew tropical speciesare available in theaquarium trade.As regards the gastropods,some speciesare considered pests -physas, for instance -while others, such asthe Planorbidae, Ampullaria,and Malaysiansnails, play apositive ecologicalrole, above all byfeeding on unwantedalgae. In good conditions, they proliferaterapidly; they can be removed by hand orby trapping them with a leaf of lettuce orboiled spinach: if you put one of these ina tank at night, the next morning it will becovered in snails. If a population of gastropodsdisappears from an aquarium, thisis probably a sign of imbalance.CRUSTACEANSIn freshwater tanks, these are mainly representedby several species of shrimps,although it is occasionally possible to find atropical crawfish, and even small crabs. Ascrustaceans' carapaces mainly consist ofcalcium carbonate (CaCO 3 ), it is advisableto keep them in hard water, and somecrabs can even live in brackish water. Carnivorousfish are obviously out of the questionas roommates. Small species of fish arenot normally at risk from crustaceans, but aweakened or sick fish may be captured anddevoured. Crustaceans' role in the wild asenvironmental regulators can be reproducedin captivity.Whatever species you may choose, all crustaceansfeel more at home if they are pro-Shrimps from the Macrobrachium genus arebecoming increasingly common in freshwateraquariums.vided with shelters, especially during themolt. If they are fed properly, this processwill occur regularly, but the animal is vulnerablewhile it is forming a new carapace.It is during this critical period in their lifecyclethat crustaceans usually attack eachother.166

MARINE INVERTEBRATESMarine invertebrates are sometimes more difficult to keep in an aquarium:on the one hand, they are very sensitive to the quality of the water, which mustbe as faultless as possible, and, on the other, feeding them is complicated,particularly in the case of sponges, Coelenterates, anemones, and corals. It is alsoimportant to consider the compatibility of invertebrates, not only with each otherbut also with fish — as invertebrates are the favorite meal of some fish!For all these reasons, the best option is aspecialist tank, which will provide a spectaclejust as fascinating as that of a fishaquarium, although those fish which cancohabit with invertebrates represent a logicalcomplement to this type of aquarium.The invertebrates which are most robustand easiest to acclimatize can reproduce incaptivity (especially some species ofanemones), but success inthis area requires a solidbackground in marineaquariums on the part ofthe hobbyist.Nevertheless, some marineaquarists hesitate to crossthe threshold from fish toinvertebrates, on thegrounds both of cost andrisk. However, these daysthere is a craze for this typeof aquarium, but you mustnot get carried away: it isnot feasible to reconstitutea coral reef, although it ispossible to achieve satisfyingresults, both in terms ofecological equilibrium andan engrossing spectacle.400-500 liters is the absolute minimum fora tank containing several species of invertebrates.A maximum height of 50 cm isrecommended to allow the light to penetrate,as well as making it easier for theaquarist to intervene. It makes sense anywayto install as large a tank as possible,as your enthusiasm for these creatures isbound to grow.Mounting a tankalmost entirelycomposed ofinvertebrates, witha few fish added,requires ampleknowledge ofthese animals. •GENERALMAINTENANCECONDITIONSThe aquariumThe bigger it is, the easierit is to acclimatize theinvertebrates. Do not considera tank of under 300liters for a medium-sizedanemone, accompanied byits clown fish. A volume of167

INVERTEBRATES• Easy-tousetestsmake it possible tocontrol waterquality, whichmust be perfect inan invertebratetank.LOWERING THE PH IN AMARINE INVERTEBRATE TANKThe pH in a coral tank sometimes undergoesslight but regular decreases. When itdrops to under 8.3, it can be raisedwith sodium carbonate. Dissolve5 g in 1 liter of water, and add1 ml of this solution to eachliter of clean water. This processis repeated every dayuntil a pH of 8.3 is obtained.There are also some readyto-usesolutions for thispurpose available in theaquarium trade.WaterThis must be stirred vigorously: use apump with an outflow equal to at leastfive times, and up to ten times, that of thevolume of the aquarium. Do not forgetthat the water in an invertebrate tank willnever be as agitated as in a natural setting.The water must be very clear, to facilitatethe penetration of light. It is therefore vitalto have good mechanical filtration, possiblyin conjunction with an air pump.Invertebrates are extremely sensitive tonitrates (NO 3 -).A box filter is indispensable, and its volumemust equal at least 10% that of theaquarium.It must be pointed out, however, thattanks containing true corals, ormadreporites, which form reefs can sometimeswork well without this type of filter.In order to facilitate the operation andreduce the burden of the filter, thusincreasing its efficacy, put the proteinskimmer in its first section. As a complementto these techniques, you are stronglyadvised to perform partial water changes,at a rate of around 10% of the volume,once a week.It is advisable to change the water the dayafter the weekly feeding session, as thiswill help to reduce pollution. The specificgravity of the water must be around 1.024,although it can go up to 1.026.LightThis is extremely important, both asregards quantity and quality. Apart fromthe aesthetic effect, lighting serves toenhance the development of Zooxanthellae,the micro-algae which live in the animals'tissues and contribute to theirequilibrium.If the water is less than 50 cm deep, usefluorescent tubes as day lighting, in conjunctionwith a blue tube. Deeper waterrequires powerful HQI lamps, again combinedwith a blue tube. The lighting mustbe strong (around 1 W per liter of water)and should be left on for about 13 hoursevery day. UV lamps are not recommendedfor invertebrates.More detailed information on lighting canbe found in the chapter Equipment andAccessories (page 226).The substrateFine-grained soils are to be avoided, a sizeof 2-5 mm being perfect. The bed must becalcareous and comprise sand made fromcorals and marine algae, which can becomplemented by crushed oyster shells toguarantee a moderate supply of calciumcarbonate.• The substrate in marine tanks consists of coralelements in fairly large grains.168

MARINE INVERTEBRATESZOOXANTHELLAEThese are green micro-algae which live in the skin of Anthozoa and other organisms, such as sponges or giant clams, atype of bivalve mollusk. They exchange substances with the cells of their hosts. The carbon dioxide (CO 2 ) resulting fromthe metabolism of the cells - i.e. the oxidation of the foodstuffs - is collected by the Zooxanthellae. These, in their turn,absorb nitrogenous and phosphorous substances, carry out photosynthesis, and produce organic substances that enhanceboth their own growth and that of their host. This type of mutually beneficial association taking place inside an animal isknown as endosymbiosis. The Zooxanthellae contribute, to some extent, to the feeding process of Anthozoa, which thereforeneed only a very scanty external supply of nutrients: some organisms, such as the anemones, need to be fed onlyaround once a week in an aquarium.• The green coloring of this Anthozoa indicates the presence of a significant number of Zooxanthellae: this animal musttherefore be placed under fairly intense lighting.The decorThis serves as a support for some animals.Create an aquascape in tiers or with steps,and place the species on it according totheir need for light. This is easy to do withartificial materials, and the decor can befinished off with dead coral and rocks.Caulerpaprolifera is acommon alga inmarineinvertebrate tanks.169

INVERTEBRATEStank is recommended. When handlinginvertebrates, be aware of the stingingcapability of some species (such asanemones and madreporites).• When wellacclimatized, theCoelenteratessoon deploy theirtentacles, which isa sign of goodhealth.170VegetationPlants release substances that have a beneficialeffect on invertebrates, although asyet we still know relatively little about themechanism of this process.Use algae of the Caulerpa genus, but donot allow them to become too dense.In addition, remain on the lookout for thegrowth of certain filamentous algae, asthere is a danger that they might smothersome sponges and delicate Coelenterates.Acclimatizing invertebratesAs the characteristics of invertebrates'native waters are radically different fromthose of the tank in which they will beplaced, great care must be taken withrespect to their acclimatization. The containerin which the new arrival has beentransported must be gradually filled withwater from its future aquarium, to enablethe invertebrate to slowly adapt before itis carefully transferred into its new habitat.The whole process takes about 1 hour.A quarantine period in an acclimatizationSPONGESSponges enjoy shadows or darkness asthey can only tolerate a small amount oflight. They do not like water with a highcontent of nitrates or filamentous algae,which smother them. They reproduce,either sexually - rarely achieved in anaquarium - or through asexual division,with a detached piece of sponge evolvinginto a new specimen.A sponge is a kind of "sack" devoid of anyspecialized organs. Water penetrates thewalls, circulates in the canals, as a resultof the movements of thousands of strandsprotecting the cells, and leaves via theopening in the top. The water providesoxygen and the particles on which thesponge feeds, particularly the micro-algaeof phytoplankton.Removing a sponge from water has fatalconsequences, as air bubbles enter thecanals where the water circulates andblock them. The sponge, unable to eliminatethe bubbles, eventually dies.Sponges are fed in the same way as Coelenterates,with a preparation based onmussels, or special liquids available commerciallyfrom specialist suppliers.COELENTERATESThe Coelenterates constitute a complexgroup (see table, page 171). They includethe Anthozoa, which are divided intohexacorals, where the number of tentaclesis a multiple of 6, and octocorals, wherethe number of tentacles is a multiple of 8.The hexacorals are divided into:- Actiniaria (true anemones);- Ceriantharia;- Zoantharia (colonial anemones);- Corallimorpharia (discus anemones);- Scleractinia (madreporites or truecorals).These invertebrates are characterized bytentacles attached to a foot, and the wholeorganism is called a polyp. Anemones andCeriantharia are isolated polyps, while

the other Anthozoa are colonial polyps,connected to each other at their base,which end up by spreading out over largeareas like certain plants.Darts for defenseThe bodies of Coelenterates, particularlythe tentacles, are covered with urticant(stinging) cells, equipped with a strandthat is sensitive to contact with otherorganisms. When a Coelenterate istouched, thousands or even millions ofcells open and eject a filament with amicroscopic dart at the tip which injectsvenom; in this way, a prey is quickly paralyzedbefore being eaten. Care should betaken when handling, therefore.MARINE INVERTEBRATESWHAT IF YOU TOUCH A COELENTERATE?Some species have a greater stinging capability than others. Seriousreactions, such as cramps or breathing difficulties, rarely encounteredamong aquarists, can be provoked by certain medusas (jellyfish),due to a phenomenon known as anaphylaxis: the body is sensitizedto the venom after an initial contact and becomes more vulnerable.In the event of an accident, detach the tentacles and, aboveall, do not rub your eyes. Treat the stung area immediately withdiluted ammonia, but it is best to consult a doctor.Introducing Coelenteratesto an aquariumCoelenterates must of course present allthe necessary signs of good health beforebeing introduced to an aquarium: theyshould be unfurled, swollen, and full ofwater. If they are in a bad state, they lookwilted and may not be viable.Anthozoa like clear and well-lit water, asit benefits both them and the Zooxanthellaeto which they play host. They must beplaced close to the surface of the aquarium.The water quality is, of course, veryimportant, and in addition the calcium

INVERTEBRATESCertain species offish and marineinvertebratesfound inaquariums comefrom coral reefs.levels must be monitored with particularlyclose attention.The skeleton of corals is mainly composedof calcium carbonate, which isabundant in the natural habitat - up to500 mg/liter - and so an aquarium that isto be inhabited by corals must also havethe same level.The concentration in an aquarium cansometimes fall below 300 mg/liter,depending on how many organisms thereare in the tank, and in these cases calciummust be added. Several relatively simplemethods for raising the calcium level aredetailed in the box on page 173.Coral reefsThe accumulation of calcareous coralskeletons gradually forms reefs, of whichthe most famous is the Great Barrier Reef,stretching north-eastward from south Australiafor almost 2,000 km. It is the biggeststructure of animal origin in the world!This ecosystem, one of the richest andmost diverse in existence, is also fragileand constantly subject to attack. The lastfew decades have witnessed the destructionof some reefs, the coral being used tobuild houses, roads, and even airport runways!Obviously, aquarists have beenaccused of taking part in this pillage,which seems grossly exaggerated: theremoval of corals from their natural habitatfor the aquarium trade does occur, butit is negligible compared to other largescaleextractions. Furthermore, somespecies are protected by law and neverreach hobbyists' tanks.Public marine aquariums can, on the contrary,make a contribution to the study ofinvertebrates. The aquarium of theMonaco Oceanographic Museum, forWHEN MUST CALCIUM BE ADDED?Calcium is added when the concentrated measured is less than 400 mg/liter. There aretests on the market to measure the quantity of this parameter. Remember that the measurementof CH, in sea water, reveals the quantity of carbonates and bicarbonates.When this is less than 7°CH (128 ppm), it can be concluded that a lack of calcium carbonateis more than likely and steps should be taken to remedy this.172

MARINE INVERTEBRATESHOW TO SUPPLY CALCIUM TO A CORAL AQUARIUMMethod 1From the start, i.e. when you put the first water in, use commercialsalts enriched in calcium. Then, add the same saltsover the course of regular partial water changes, at therate of 10% per week.Some commercial salts are specially designed for marineinvertebrates. •Method 2Use commercial products specially prepared to increasecalcium levels.Method 3Place a calcareous element, such as calcareous rock, or crushed and washed oystershells, in the filter, and this will gradually release calcium. However, this method will notgive rise to any rapid or significant increase in calcium levels.Method 4Prepare a solution of slaked lime, Ca (OH) 2 , available in aquarium stores, at a rate of 1.5g/liter. Pour in 1 ml of this solution per liter of sea water.Proceed gradually, monitoring the pH constantly to ensure it does not rise above 8.5.Method 5This is the most complicated, but also the most effective.Prepare two solutions:- one of dehydrated calcium chloride (CaCI 2 , 2H 2 O) at a rate of 15 g/liter, which willprovide the calcium;- the other of sodium bicarbonate (NaHCO 3 ), at a rate of 17 g/liter, which will providethe carbonates.Then calculate the difference between a carbonate hardness of 130 ppm (7.2°CH)and the one measured in the aquarium. Multiply the result by the net volume of thetank, and divide the result by 10. This will give the amount of each solutionrequired, in milliliters, to pour into the aquarium.Example: for a tank with a net volume of 500 liters, with a carbonate hardness of100 ppm (5.6°CH), the result is:Amount of each solution (in ml) = 500 x (130-100) + 10 = 1,500 ml.The following table gives you the required amount of each solution (in ml) for specific cases.When addingcalcium, the pHvalue must notrise above 8.5,regular control isnecessary.173

INVERTEBRATES• The leathercorals of theSarcophyton genuswill not toleratebeing dose toCoelenterateshighly prone tostinging.In their naturalhabitat,Coelenterates feedon animalplankton, butthese are difficultto supply in anaquarium. •example, is carrying out research in thisfield, using a 40 m 3 tank containing severaltons of corals, which are nurtured andbred. Until recently, raising corals on thisscale in captivity was impossible, above allbecause of their very great sensitivity tonitrates (NO 3 -). Scientists solved this problemby allowing these nitrates to turn intonitrogen gas (N 2 ), thanks to the anaerobicbacteria which survive at the bottom of thetank, where the oxygen levels are low.The nitrogen produced by the metabolismof these bacteria then passes into theatmosphere.This complicated technique is beyond thereach of most aquarists, however experiencedthey may be.Feeding CoelenteratesBy filtering the water, the Coelenteratestrap small suspended particles, particularlythe crustacean zooplankton. Collecting,keeping, and distributing plankton isnot a task to be taken lightly, and it is bestto look for other solutions.However, it must be made clear that commercialfoods on the market provide littlemore than a stopgap.It is possible to use rotifers or freshlyhatched brine shrimp nauplii, normallyused as the main food for fish, but noteverybody breeds these animals. There isanother food which is available to all hobbyists,as it is inexpensive, easy to make,and can be frozen: it is usually called musselchoppy. Mussels are not only cheapbut also rich in proteins, carbohydrates,mineral salts, and vitamins. Other possi-FOOD FOR SPONGES AND COELENTERATES: A RECIPEIngredients:- mussels or cockles;- white fish, i.e. lean and free of lipids;- shelled shrimps in cans (optional).Cook the mollusks and fish. Put the shrimps in boiling water for 1-2 minutes.Remove the mollusks' shells.Mix all the ingredients thoroughly. You can add a vitamin solution, flakes or granules of fish food,boiled spinach, or the special foods for invertebrates available commercially. If the paste is too thickafter mixing, thin it with sea water.Pass the mixture through a sieve. What is left behind in the sieve can be distributed to anemonesor small fish; this puree can also be frozen. Allow the puree to stand for several hours in the refrigerator,then discard any excess water.The resulting paste can be used straightaway for feeding, or can be frozen.It is best to put the food into the aquarium at night, 1 or 2 hours before switching off the lights.Switch off the filters, pumps, and aeration for a moment. Thaw the food, if necessary, and distributethe equivalent of one tablespoon of the prepared liquid for every 200 liters of water. Deposit thefood above the invertebrates with a narrow, rigid tube. The filtration and aeration systems can beswitched back on a few minutes afterwards.174

MARINE INVERTEBRATESTheCoelenterates cancohabit with algae- encrusting orotherwise - andeven with smallfish.bilities are cockles, the flesh of lean fish,or cans of shelled shrimps, which are producedin large quantities in Asia, cost little,and are readily available.The other problem is establishing a feedingschedule. It must be remembered thatthe majority of organisms being fed playhost to Zooxanthellae, which often satisfya significant proportion of their dietaryneeds, and so a weekly feed is more thansufficient. Do not forget that the best timefor this is the night before a water change,to reduce the risk of pollution.The larger anemones feed on adult brineshrimps, small pieces of mussel, fish, orshrimps or a mixture of these.Compatibility between CoelenteratesUrticant (stinging) Coelenterates must bekept apart from the more delicate species:a safety margin of 10-15 cm is often recommended.The madreporites andanemones are among the most urticant,and they must not be put alongside aleather coral from the Sarcophyton genus,for example. Other alternatives for a Coelenteratestank are algae - whetherencrusting or not - supported by liverocks, or even caulerpae. Their developmentmust be controlled so that they donot end up smothering the Anthozoa. Theintroduction of certain fish is possible,even desirable, but there are cases of classicincompatibilities (see table, page 178).Specially designed artificial decor can becolonized quickly, depending on theorganisms' rate of growth and reproduction.This can sometimes make it difficultfor even a practiced eye to spot the differencebetween artificial and naturaldecor in an aquarium which has been inoperation for several months.WORMSSome species belonging to the Annelida, agroup that includes the sea worms used asbait in fishing, live in a tube which theybuild themselves: these are known asIn aninvertebrate tankthe developmentof algae must berestrained, so thatthey do notsmother theCoelenterates (left,a Cerianthus).175

INVERTEBRATES• This cowry haswithdrawn itsmantle into itsshell.sedentary Annelida. The brightly coloredbranchial plume which sticks out of it trapsoxygen, as well as the organisms whichmake up zooplankton. At the sign of anydanger, or if the tank or its support areknocked, this branchial plume retreats intoits tube. The feeding of Annelida in captivityis identical to that of Coelenterates.When you buy one, make surethat the branchial plume is functioningcorrectly and its tube isintact. It is best to buy a wormfixed to a piece of rock.cowries, well known to collectors of shells,can be kept in captivity. Some fish maynibble the "mantle", the part of the animal'sbody used outside the shell.Of course, in the event of any danger theanimal retreats into its shell. Hobbyistsenchanted by the beauty of this shell canput a specimen in a tank containing smallPacific fish (Gobiids, Blenniids, Grammids.Pseudochromis, for example). In thebivalve group there is the famous giantclam, which can sometimes grow up to alength of 1 m in the wild, where it feeds onvegetal plankton. Some smaller species canbe acclimatized in an aquarium. However,these animals are only recommended forexperienced hobbyists.CRUSTACEANSIt is easy to keep a few species in amarine aquarium, to take advantage oftheir bright colors. These invertebrates arecarnivorous: in an aquarium they shouldbe fed on mussels, fish, or white meat.Shrimps play anecological role byfeeding on fishes'leftovers.MOLLUSKSFew mollusks are found inaquariums, and they are notoften available commercially.Among the gastropods, the• Hermit crabs are highly striking invertebrateswhich run around the aquarium in all directions tolook for their food. They withdraw into their shellwhen frightened.176ShrimpsThese rarely swim and prefer to get aboutby walking on the decor. If they are disturbedthey abruptly recoil by tucking uptheir abdomen. Several specimens can livetogether, but it is vital to keep them awayfrom carnivorous fish.

food or a sucker. Thelatter allows seaurchins to develop onrigid supports or theglass sides of the tank.MARINE INVERTEBRATES• Enomotoplus sp., the lobster crab, related to thelangoustine, is an attractive and placid resident.CrabsThe small abdomen is tucked under thelower part of the body. Their pincers areparticularly well developed. The largerspecimens, which can be aggressive, mustnot be put into marine aquariums, as theycan attack other invertebrates, and sometimeseven fish.PaguridsThese are better known as hermit crabs.Some tropical species can be found commercially,some of them bearing a smallanemone on the gastropod shell whichhouses them. The shell is discarded whenit becomes too small for the growing animal,so it is vital to provide bigger ones,as, unlike other crustaceans, a pagurid'sabdomen is not protected by a carapacethat it makes itself.StarfishThese are not recommendedfor a marineinvertebrate tank, asthey attack otherspecies, such assponges. Starfish arein fact either carnivorous,gripping theirprey with their longarms that emergefrom a central disc, ormicrophages, inwhich case they feedon small organismson the bed.The ophiuroids, sometimes called brittlestarsand closely related to starfish, havearticulated arms which allow them tomove around quite quickly. These arms,like those of the starfish, can regeneratethemselves if they break off."LIVE ROCKS"These are pieces of rock or fragments ofdead coral (madreporites), that are boundtogether by calcareous rocks or variouspieces of debris from invertebrates. TheySome speciesof sea urchins withvarying sizes ofprickles can befound in marineaquariums.ECHINODERMSSea urchinsThese are not very easy species to acclimatize.It is possible to keep one smallspecimen at most, which will often liveaway from the light. They are herbivoresthat sift the substrate looking for algae toeat. In among the prickles it is possible tosee the articulated pedicellariae, whichend either in a tiny pincer for trapping"Live rocks" are covered with many smallorganisms (worms, Coelenterates) which would bedifficult to introduce into an aquarium in any otherway. •177

INVERTEBRATESare sometimes removed from their naturalsetting and sold commercially. "Liverocks" harbor various organisms: bacteria,algae, sponges, small Coelenterates, andsometimes even small crustaceans, hiddenin crevices. They can therefore be consideredas living pieces of decor which contributeto the equilibrium of the aquarium.If, before sale, they have been suitablytransported, cared for, and housed, thenthey are worth acquiring, despite theirhigh price, as they permit the introductionof a variety of beneficial organisms intothe aquarium, in the most "natural" waypossible.Another option is to collect these types ofrock yourself, off the shores of Florida, forexample. Organisms capable of survivingin a tropical tank grow there in summer,when the water temperature is higher.There is always a chance, however, ofintroducing an undesirable organism or offinding that some residents of the "liverock" deteriorate and die, with an ensuingrisk of pollution. It is therefore best toproceed with caution and isolate the rockin a quarantine aquarium.COMPATIBILITY BETWEENINVERTEBRATES AND MARINEFISHInvertebrates cannot cohabit with just anyfish, for a number of reasons. The first isthat they are liable to become prey forcarnivorous fish. Coelenterates are completelyincompatible with angelfish(Pomacanthids), for example. Secondly,some lively and active fish, of over 10-15cm in length, can jostle and disturb invertebratesin the aquarium.Furthermore, the bigger and more active afish, the more it excretes nitrogenous substances,leading to the accumulation ofnitrates (NO 3 -), which are harmful toinvertebrates. It is therefore best to avoidthe presence of this type of fish. Toomany fish produce the same result and thesame degree of harm for invertebrates.Finally, there is another problem when asick fish has to be treated, particularlywith substances containing metals, whichare toxic for most invertebrates. Rememberthat it is always preferable to nurse afish in a hospital aquarium.178

INVERTEBRATESThese days, more and more aquarists seem to be taking an interest inthese animals. Ecologically speaking, invertebrates represent a naturalcomplement to fish and plants; in visual terms, you can put on aspectacle of luminous beauty, particularly in sea water, usinganemones and corals, to which can be added small fish, either livelyor placid, but always brightly colored. There are also a few species offreshwater mollusks and crustaceans which are easy tokeep in captivity, although they are little known andoften overlooked.

FRESHWATER INVERTEBRATESGASTROPODSThese are often unintentionally introducedinto aquariums, usually viaplants containing eggs or small juvenileswhich are difficult to spot. Gastropods laytheir eggs in a small, transparent, gelatinousmass.AmpullariaSome species of the apple snail can grow to 20 cm inthe wild, but those found in an aquarium (belongingto the Ampullaria genus) do not exceed 7 cm. They eatvegetation and detritus, helping to restrict thedevelopment of algae, and like fairly hard water.Unlike many other gastropods, they are sexed and laytheir eggs outside the water. Size: 6-7 cm.• Ampullaria gigasPlanorbisThese are water snails with a flattened shell. Their orange-red body containsplenty of red globules to establish a high oxygen concentration, as they livein environments lacking in oxygen and breathe through their lungs,sometimes rising to the water surface. They graze on both short andfilamentous green algae, whose growth they help to restrict.Size: 3-4 cm.Planorbis sp.Malayan snailsThey breathe through their branchiae and can retreat into theirtapered shell, which closes with an operculum. They relish the tinyalgae which encrust the decor; if they are well fed, they proliferatequickly. They are considered less effective than the planorbis, but asthey bury themselves, they contribute to the equilibrium of the aquariumby turning over and aerating the bed. If you want to get rid of them,introduce a fish from the Tetradon genus, which will appreciate thesemollusks. Several Malayan snail species belonging to the Melanoides genus(such as Melanoides tuberculata), native to South-East Asia, can beunintentionally introduced into tanks along with plants. Size: 1-2 cm.PhysasTheir spiraled shell is markedly less elongatethan that of Malayan snails and they arealso slightly bigger. They do not play animportant role in the control of unwantedalgae. As they reproduce rapidly, it is bestnot to introduce them into an aquarium.Size: 1-2 cm.Melanoides sp.(Malayan snail)Physa sp. •180

CRUSTACEANSCRUSTACEANSThe word crustaceans usually brings marine species to mind, and it is often forgotten that they also livein fresh water. Less colorful than their marine cousins, they are nevertheless interesting to observe.They prefer hard water, on account of the calcium carbonate that forms their carapace.ShrimpsFew species are commercially available, even though theyare abundant in certain tropical regions. Several specimenscan live together, if there are a sufficient number of sheltersto provide hiding places in the aquarium.AtyaThese shrimps are found in many tropical regions in the Americas, Africa, andAsia, sometimes in brackish water. They are bottom-dwellers that feed onleftover food - both natural and artificial - and fish, and so their ecologicalrole is quite substantial. These shrimps from the Atya genus (particularly Atyamoluccensis, native to South-East Asia) are only occasionally found in theaquarium trade. They like lively, well-oxygenated water and are sociable, andso can be kept in small groups. Size: 6-7 cm.• Atya moluccensisPalaemonidaeThis family includes the familiar pink shrimp, as well as a largenumber of freshwater tropical species, such as the genusMacrobrachium (which covers some 200 species). These longpincershrimps are sometimes raised for restaurants: this is thecase with M. rosenbergii, which grows to 25 cm, withoutcounting its pincers.It is the smaller species that are sold in the aquarium trade, withM. lanchasteri being the most common at the moment. Native toSouth-East Asia, it acts as a garbage collector in a tank by eatingthe particles left behind by the fish. This shrimp likes filtered lightand shelters for taking refuge if it is disturbed. When it is reallyfrightened, it can jump out of the water to escape from danger.It is prone to attack the fish fry, which it easily detects with itsacute sense of smell. Size: 7-8 cm.Macrobrachium sp.CrawfishThere are around thirty species of crawfish in the world, distributed across the temperate and subtropicalzones. Although some European species can adjust to tropical aquariums, it is advisable to let them remainin the wild as the regulations concerning their entrapment are strict.One crawfish, Procamburus darkii, the Louisiana crawfish, has beenimported by a number of countries. It can cause a great deal of damage as itis fossorial and burrows in river banks.It grows quickly (starting to reproduce at the age of 7 or 8 months) and ishighly adaptable, as it tolerates a wide range of temperatures and requireslittle oxygen. Many of the imported specimens come from South-East Asia,where there are red and blue varieties.It is omnivorous and can attack plants and fish, as well as other crustaceans. Itis therefore best to keep a single specimen, even if the aquarium is very bigand endowed with hiding places. Size: 15 cm.• Procamburus clarkii181

MARINE INVERTEBRATESSPONGESThe form and color of sponges are extremelydiverse: balls, mats, or tubes, in red, orange, yellow,brown, or gray. They attach themselves to a support(rocks, but also dead coral or mollusk shells) andshy away from the light. Sponges seem to proliferatespontaneously in marine tanks, as they can be introduced,in sizes invisible to the naked eye, along withother invertebrates, live rocks, or in water. Both the commonand scientific names are little known and it is difficultto ascertain with any exactitude which species are found inthe aquarium trade in the absence of detailed research.COELENTERATESThese are the favorites among aquarists that specialize in invertebrates,although their availability - and their price - can varyenormously. Furthermore, there is sometimes confusion over theirnames: some species may not even have one as they have yet tobe systematically studied and described!HexacoralsThis group covers the majority of the Coelenterates found in marineaquariums, particularly anemones and corals. Do not forget thatmost of them need strong light, as they contain Zooxanthellae, andthat they can be fed on small morsels of animal origin. The aquaristmust take care when handling some species, as their capacity tosting can be considerable. The great majority of these animals areimported from the Indian or Pacific Oceans, but they are only sporadicallyavailable in the aquarium trade.• Red Sea spongeAnthozoa sometimes provide a refuge forshrimps, protecting them from theirpredators.Sea anemones (Actinia)These live on the substrate, attached by their single foot, which acts as asucker, but they can move around and find the place that suits them best(sometimes the tank's front pane). Some rare species live in the sand and canretreat into it. They are fairly robust in an aquarium if in water that is well litand aerated (some anemones have Zooxanthellae). A large living space musttherefore be planned for them, as other Anthozoa do not appreciate theirtentacles; moreover, they sometimes excrete filaments of mucus that canpollute the water. Only clownfish can accustom themselves to contact withtheir tentacles. Anemones eat small pieces of mussel, shrimp, fish, or achoppy made from these ingredients. Sexual reproduction is a possibility, andsome anemones are livebearers; asexual multiplication can take place viabudding, which will go on to produce a young anemone. When buyinganemones, make sure that they are puffed out and unfurled, as these aresigns of good health.Heteractis (formerly Radianthus)This has a large number of tentacles, which are quite long (up to 10 cm) andsomewhat rigid. Species of this genus can achieve a diameter of several dozencentimeters, and they are appreciated by several species of clownfish.Diameter: 30-40 cm.Heteractis magnifica182

COELENTERATESStichodactyla (formerly Stoichactus)In its natural habitat a species of the Stichodactyla reaches lengths of 1 m. The tentaclesare arranged in dense ranks, particularly round the edge of the anemone.Diameter: 20-50 cm.EntacmaeaThis genus was created a few years ago to cover some species from the old Radianthusgenus (the remainder being included in the Heteractis genus).AiptasiaThe glass anemones are oftenintroduced to an aquariumalong with rocks or water. Theyare livebearers that can quicklycolonize a tank, to thedetriment of other Anthozoa.However, they do haveadvantages in an aquariumwith butterfly fish(Chaetodontid family), as theyconstitute these fishes' staplediet. Diameter: 5-10 cm.• Stichodactyla mertensii• Entacmaea quadricolor sheltering theclownfish Amphiphon bicinctus.CerianthariaThese resemble anemones, although they can be distinguished by their non-retractabletentacles. Moreover, they are not attached by a single foot but live in a self-secreted tube,whose support requires a layer of not too rough sand, 15-20 cm thick.Ceriantharia feed on finely ground mussels, fish, shrimps, or brine shrimps. Certain speciescan sometimes be found in the aquarium trade, although their name is often unknown orincorrect. Height: 20-30 cm.• Aiptasia sp.Parazoanthus sp.Cerianthus sp.Zoantharia (colonial anemones)These are neither anemones, as they live in colonies, nor corals, as they have nocalcareous skeleton. These animals colonize rocks, mollusks' shells, and sometimessponges, corals, and Gorgonians. They can harbor Zooxanthellae, and therefore need theappropriate light level.Parazoanthus sp.This colonial anemone consists of small polyps which can reach a height of up to 2 cm,with tentacles that do not exceed 5 mm in length. They must be placed 10 or 20 cm underthe water surface in an aquarium to take maximum advantage of the light, due to thepresence of Zooxanthellae. They must not be put close to stinging Anthozoa. Like manyother animals in this group, their food consists of a fine choppy based on mussels. Whenbuying this encrusting anemone, make sure that it is attached to a rock.183

MARINE INVERTEBRATESCorallimorphariaThese invertebrates, which are not corals - they have no skeleton - are known as discus anemones.They live attached by a foot that is less powerful than that of the anemone. The diameter of the discshapedpolyp varies from one species to another. The presence of Zooxanthellae demands stronglight. Asexual reproduction through budding is possible in captivity. Size: 10-30 cm.ActinodiscusSeveral species from this genus are available on the market, and they are easy to keep. Their feeding,identical to that of the animals above, should take place on a weekly basis, as Zooxanthellae supply apart of the substances they need to live and they sometimes reject the food offered by the aquarist.ScleratinariaTrue corals or madreporites live in a calcareous skeleton, into they which they can withdraw. Thisskeleton means that they make the most significant contribution to the building of coral reefs intropical seas. These are the most difficult invertebrates to keep in a marine tank, as they require wellaeratedwater of the highest quality, with no suspended particles - and therefore crystal clear - andan extremely low nitrate content. As they are very sensitive to nitrates, it is essential to partiallychange the water on a regular basis, in small volumes. The tentacles, often drawn in by day, unfurl atnight to capture food. This does not mean that corals like darkness; on the contrary, they must beprovided with a great deal of light, on account of the presence of Zooxanthellae. They arecarnivorous, feeding on animal plankton in their natural habitat and a choppy based on mussels orfish in captivity, once a week. A supply of calcium carbonate is desirable for the growth of theskeleton. Take care when placing them in an aquarium, as they should not come into contact withother Anthozoa once their tentacles have unfurled.• Actinodiscus sp.• Acropora sp.Goniopora sp.Acropora (Acroporidae)They are rarely imported alive buttheir skeletons are often used asdecor in domestic aquariums. Inthe wild, their growth is rapid (afew centimeters per year) andthey can exceed 1 m in height.Height: 20-50 cm.Fungia (Fungids)These solitary (and therefore noncolonial)corals generally live on thesediment and do not take part in theconstruction of reefs. The distinctive skeletoncan be used as a decorative feature. Diameter: 20 cm.Goniopora (Poritidae)The species from this genus are imported on a fairly A Fungia sp.regular basis, and are some of the easiest to keep in anaquarium. They prefer moderately aerated water. Size: 20-30 cm.Favia, Platygira (Favidae)These are easy to keep in captivity and accept small, live prey. The colored tentacles are drawn in by day.Size: 20 cm.Leptosammia (Dendrophylliidae)One temperate species in this genus also tolerates tropical temperatures:Leptosammia pruvoti.Half-open Plerogyra sp SomeIts yellow-orange color and small size make it good for decoration. It is tentacles are visible; the green colorpreferable - in fact, essential - to put it into the aquarium alreadyis the result of Zooxanthellae.attached to a support. Size: 5 cm.Plerogyra (Caryophylliidae)The species in this genus, known as bubble corals, are quite easy tokeep in an aquarium. The daytime "bubbles" withdraw at night togive way to stinging tentacles 1-5 cm long. In the wild, the bubblesprovide the coral with a certain degree of protection, as the tentaclesare not attacked by fish (butterfly fish, for example). The color of thebubbles varies depending on the presence of Zooxanthellae, and thesemean that this coral requires strong lighting. It is best to feed it at night- when the tentacles are unfurled - with relatively large, live prey. It isalso possible to accustom it to eating a fine choppy based on seafoodbetween the bubbles by day. Avoid allowing the bubble coral totouch other invertebrates, on account of its capacity to sting. Size:20-30 cm.184

WORMSOctocoralsThese live in colonies in both temperate and tropical seas. Theyare able to build a skeleton, but it is not the same as that of themadreporites. Their tentacles, numbered in multiples of eight, are1-5 cm long. Their reproduction is either sexual or asexual,through budding. As with the hexacorals, some species can houseZooxanthellae.Sinularia sp., soft coral from the Indo-Pacific region.Alcyonarians (or soft corals)These live attached to the substrate by a horny secretion, and their polyps canbe withdrawn. The presence of Zooxanthellae means that they require stronglighting.Sarcophyton (Alcyoniidae)When they expel water from their tissues to renew it, they look like leather,hence their name leather corals. They are easy to keep in well-aerated waterand they grow quickly. Theircolor varies according to theconcentration of Zooxanthellaepresent.Their weekly diet consists of afine choppy of mussels andother seafood. They must bepositioned with care in theaquarium, well away fromother stinging species. Twoleather corals are mostcommonly found in theaquarium trade: Sarcophytonglaucum and 5.trocheliophorum.Size: 20-30 cm.A FALSE CORAL,A TRUE GORGONIANThe red coral (Corallium rubrum) found in theMediterranean, up to a depth of 200 m, is in fact aGorgonian. These days there are no colonies over afew dozen centimeters, and their disappearance canbe attributed to fishing offthe coasts of France,Sardinia, and Tunisiathat is so intensiveit is best describedas pillage! Suchdemand is explainedby the factthat the brightred skeleton ofthis species isused in jewelry(particularly so inItaly).Sarcophyton sp., closed (left)and with the polyps extended(right). •GorgoniansThe species in this group, which comprises several families, present a ramified,fan-like form and can grow to a height of 2 m. Their skeletons can be used fordecorative purposes. These animals prefer a fairly dark environment, where theylive attached to a support. They sometimes have a tendency to be colonized byother organisms, such as sponges or filamentous algae. Their food must be veryfine and distributed daily. Size: 15 cm.WORMSGorgonian and AlcyonarianWorms belonging to the genus Sabellastarte are sometimesimported. The branchial plume (in a doublecrown) can reach 15 cm in diameter. It is best to keep themaway from stinging Anthozoa. Their diet is the same as thatof the Coelenterates.Sabellastarte sp.185

MARINE INVERTEBRATESMOLLUSKSertain species of mollusks can be kept with fish, and sometimes with otherinvertebrates, so they are popular among hobbyists.GastropodsCypraea tigrisThe species found in the aquarium trade are mainly carnivorous and feed on mussels or fish. There areothers which graze the algae on the decor.CypraeaThe highly decorated shell of the Cypraea is much prized by collectors. In aquariums the porcelain-like shell is only visible when themollusk is at rest; when they are active, it is covered by the mantle (the most external part of the body), containing the sensitive organs.Two species are sometimes found on the market, both with a carnivorous tendency: the tiger Cypraea (Cypraea tigris), over 10 cm inlength, and the geographical Cypraea (C. mappa), which rarely exceeds 7 cm. They are mainly active at night.Other speciesSmall gastropods can sometimes be introduced on live rocks; they are not difficult to keep, as they are herbivores. In contrast, the speciesbelonging to the Murex genus eat by piercing the shell of other mollusks, so they can be fed small mussels, shelled or intact.BivalvesIt is sometimes possible to come across small specimens of the giant clam (Tridacna genus) that canbe fed on mussel choppy. Most species have Zooxanthellae on the outer part of their mantle, andthey must therefore be placed close to a strong light source. Giant clams are demanding as regardswater quality. Generally speaking, they need a certain amount of protection, nevertheless, they canbe sold legally, although they are rarely found in the aquarium trade. Those that do appear on themarket are mainly raised in tropical areas - and they are expensive. Size: 5-25 cm.Tridacna sp.Stenopus hispidus •CRUSTACEANSThe most common species in marine aquariums are shrimps - usuallybrightly colored, although more subdued species are also found- and they are imported on a fairly regular basis. These animals pick upfood left over by fish and in this way they contribute to the equilibriumof the aquarium.ShrimpsThese very brightly colored animals are much appreciated by hobbyists for the theatrical flourish they add to a tank. They are relativelyeasy to keep if the water quality is good and the aquarium is equipped with hiding places. New species regularly crop up on the market.Stenopus hispidusThis is one the most common shrimps in the aquarium trade. In their natural habitat (several tropical seas), the barber shrimps live incouples and serve as cleaners, especially for angelfish (Pomacanthids). They abandon this role, totally or partially, in an aquarium if theyare well fed. Like many shrimps, they pick up the food rejected or ignored by fish. The male searches for food and gives it to the female.It is best to keep a couple in a tank and provide them with hiding places, where they will take refugeby day, as they are most active in the dark. In good conditions, this shrimp molts several times in ayear, particularly if it is well fed. Size: 7-8 cm.Lysmata amboinensis (formerly L. grabhami)This very sociable cleaner shrimp tolerates the presence of other shrimps and can also live in groups.It cleans the skin of certain fish with its antennae, which also detect the presence of the specimen tobe "cleaned." Apart from the usual food, you can also try providing filamentous algae for this shrimp,as it searches for microorganisms in them. Size: 7-8 cm.186Lysmata amboinensis

ECHINODERMSLysmata debeliusThis is a timid species that lives in couples and prefers temperate waters to tropical ones.The red shrimp is still rarely found on the market, like other species of the same genus,such as Lysmata wurdemanni. The latter resembles the L. seticaudata, which is native tothe Mediterranean and also to tropical regions, and is very popular in Europe.Size: 7-8 cm.Lysmata debeliusCrabsSome small species can occasionally be found in the aquarium trade. In captivity, it is bestto keep a single specimen, which can be fed on nauplii of brine shrimps or very fineslithers of mussels. Species of the Neopetrolisthes genus (porcelain crabs) live insymbiosis with anemones (for example, Stichodactyla gigantea) and feed on smallparticles using a pair of claws equipped with tiny fringes. Size: 4-5 cm.Hermit crabs (or pagurids)These are sometimes considered the garbage collectors of the aquarium as they eat awide range of detritus. It is not advisable to introduce them into a tank with otherinvertebrates (except, perhaps, the smaller species), although there is little risk in anaquarium inhabited by fish, as they can withdraw into their shell. The names of thespecies found on the market are often not known. Size: 4-6 cm.• Neopetrolisthes sp. cannot livewithout an anemone, such as one from theStichodactyla genus.Other crustaceansOdontodactylus scyllarusThe aggressive mantis shrimp spends much of its time prowling and swimming in search of food, but, even though it can bury itself insand, it also needs a hiding place. In the light of its behavior and feeding habits (small crustaceans and fish), the mantis shrimp must notbe kept in an invertebrate aquarium. Its size and agility make it suitable for cohabitation with certain fish. Size: 10-15 cm.Enoplometopus occidentalisContrary to what may be inferred from its common name of lobster crab, this decapod, closely related to the langoustine, is not aggressive.By day it remains hidden in a shelter, coming out at night to feed on the bed of the aquarium (leftover fish food, especially mussels, andsometimes filamentous algae). This is a crustacean worthy of a place in an invertebrate tank. Size: 10-15 cm.ECHINODERMSThese invertebrates are the hardest to find in the aquarium trade,although they are fairly resistant and survive well in a tank.Sea urchinsThese crawl over the decor to graze on the algae which form their diet. Becareful, because they are highly prized by Balistids, puffers, and some Labrids,which have teeth strong enough to break theinternal calcareous skeleton of sea urchins,and do not seem to be put off by their stings.The names of the extremely few speciesavailable are not knownwith any precision.Size: 10 cm.Eucidaristribuloides, nativeto the Caribbean.• Linckia laevigata, a microphagestarfish that can cohabit with otherinvertebrates.StarfishThese survive well in an aquarium. Worthy of noteamong the carnivores are the Protoreaster and Oreastergenera, which feed on other invertebrates, especiallythe bivalve mollusks. They must not be kept in a tankwith other invertebrates. Feed them with raw orcooked mussels. Other genera, such as the Echinaster,Linckia, and Fromia, are microphages and feed on theassorted debris found on the aquarium bed. They arepreferable to the carnivorous starfish in an aquarium.The ophiuroids are attractive echinoderms in a marineinvertebrate tank; they can be accidentally introducedwith live rocks. Size: 10-15 cm.187

ORIGIN AND VARIETY OF PLANTSThe vast majority of aquatic plants are not taken from the wild but are grown by specialistfirms. These plants serve as decorative elements in the aquarium, but this is not their onlyrole, as they also contribute to its ecological balance, especially via their production ofoxygen when in the light.An enormousvariety of plantscan be cultivated,in this case underglass, in anextremely hot andhumidatmosphere.190THE ORIGIN OF AQUARIUMPLANTSAll aquarium plants will reproduce intanks, so there is no point in collectingthem in their natural setting, unless youwant new species or a pure variety. Someplants sold in aquatic stores are merehybrids bearing the name of one of its two"parents", which can sometimes lead toconfusion. The collection of certain plantsfrom the wild is prohibited.Aquarium plants are cultivated by specialistcompanies, mainly in South-East Asiabut also in Europe and the United States.Agricultural greenhouses are used, partlyheated by solar energy, or sometimesgeothermically, using hot water pumpedinto irrigation canals. Sunlight may becomplemented by artificial lighting if theplants demand this.Most species are raised with a large part ofthe plant - or even all of it - outside thewater, although the environment isextremely humid. They adapt to theaquarium setting, but tend to change theshape of their leaves when introducedinto this different environment.• Most aquarium plants are raised out of water.DIFFERENT TYPES OF PLANTSContrary to what one might expect, mostof the plants found in aquariums are notreally aquatic. They generally live partlyout of the water, with only the lower portionpermanently submerged. Their leavesare sturdy, unbroken in form, and quitebig. When the level of rivers and pondsrises due to rain - sometimes very heavyin tropical regions - the plants end upalmost entirely, or sometimes even completely,covered by water. They developsubmerged leaves, which are differentfrom those which appear outside thewater, being finer and more delicate. Atthe end of the rainy season, the waterreturns to its initial level, and the plantreassumes its previous form.Other plants are totally aquatic, with theupper part of their stems only rarely seenabove the water level - usually to producea flower.There are also amphibian or totally aquaticmosses, that are very useful in aquariums,as they provide a place for some fish to lay

PLANTS• Plants with fineleaves are prizedboth byherbivorous fishand other speciesthat lay their eggson them.The effect createdby plastic plants isnot always inexquisite taste! •192their eggs. Another option is ferns, notonly the best-known species from temperateregions but also those from the tropicsthat can survive entirely submerged bywater.PLASTIC PLANTSIt is possible to find excellent imitations of naturalplants, but as an aquarium is a reconstitutionof a piece of nature, it is easy to see whythey are totally off limits for many aquarists,who prefer their plants to be natural. Some ofthese artificial plants, however, can serve as asupport in a rearing tank for those species offish that lay adhesive eggs.PLANTS IN A MARINEAQUARIUMThere are substantially fewer marineplants suited to an aquarium than freshwaterones. The most common are fromthe Caulerpa genus, which grow quicklyunder the right conditions. These algaeattach themselves to the floor and decorwith a runner. They are highly recommendedin a marine tank, as they arebound to enhance the overall balance.Their exuberant growth, however, cansometimes interfere with fixed marineinvertebrates, such as anemones andcorals. This anarchic behavior must thereforebe restrained by regularly eliminatinga certain amount of this vegetation.THE ROLE OF PLANTS IN ANAQUARIUMContrary to what is often thought, plantsdo not merely serve as decoration but alsomake a major contribution to the equilibriumof the aquarium (see page 196 onthe mechanism of photosynthesis): byday, they absorb carbon dioxide (CO 2 )given off by fish and produce oxygen(O 2 ). Moreover, they absorb nitrates, theend product of the nitrogen cycle (seepage 19), and thus reduce the concentrationin the water.Plants are similarly useful for fish. Somespecies (like Ancistrus and Gyrinocheilus)feed on algae that grow on the decor, oreven on fine-leafed plants (as in the caseof livebearers from the Poeciliid family),though this can spoil the visual effect.Others, such as South AmericanCharacins, lay their eggs on the foliage,which helps to keep them out of sight ofpredators. Fish such as scaklares, watchingover their eggs, use large leaves to fanthem. When the fry are born, they findshelter in the vegetation - particularlyplants with floating leaves - as well asnourishment there, as the plants enhancethe development of microorganisms likeinfusorians, which are a valuable foodsource.Finally, if the vegetation is sufficientlylush, it can also provide welcome shadeand hiding places for adult fish.

ALGAE PROBLEMSThe large majority of aquarists have found themselves confronted withundesirable levels of algae that are sometimes difficult to combat.Generally speaking, it is better to avoid excess growth in the first placethan to have to try to fight it- often with varying degrees of success.ALGAE OVERGROWTHThis overgrowth can be recognized by itsgreenish or yellow-brown color, (whilewhitish or gray filamentous masses, madeup of bacteria and fungi, may also bemixed in with algae). This type of growthcan form quite thick layers on the glasspanes, the bed, and the decor, appearingas filamentous tufts or even completelycovering other green algae.While a modest presence of algae can beconsidered a sign of equilibrium, thisovergrowth is evidence of a degree ofimbalance, and so algae are often referredto as biological indicators. You must becareful, however, as every aquarium is aspecial case, and applying a generalizationto a specific situation could ultimatelylead to the wrong conclusions.The disadvantages of algaeApart from being an eyesore, excess algaegrow on the panes, reducing the visibility.They attach themselves to plants and proliferate,with the subsequent risk of suffocatingtheir hosts, as the plants areprevented from exchanging gases andabsorbing the salts in the water. Finally,they incrust themselves on the slightestdetails in the decor, which does nothingto enhance the visual effect.... and their advantagesThese are substantial. Algae consumenitrogenous substances, particularlynitrates, and sometimes ammonia. This isthe normal role of plants in fresh water,and algae can therefore complement thisaction or, on the contrary, exert an antagonisticeffect by diverting nutritious saltsaway from the plants. The vegetation isless abundant in marine tanks, and soalgae - particularly the filamentous greenones - can play an important role.Algae can also be grazed or ground bysome fish. In fresh water, this applies tothe Poeciliids and the species known as"suckers" or "washers" (Gyrinocbeilus,Ancistrus, Hypostomus, Panaque, Otoclinchus,Epalzeorbynchus). In sea water,algae form part of the diet of fish families,such as the Chaetontids, Centropyges, andAcanthurids; their presence in an aquariumcan help these fish acclimatize themselvesto the artificial environment of thedomestic aquarium.COUNTERING ALGAEPROBLEMSMechanical methodsAlgae can be removed by hand, by slidingthe leaves of the plant between the thumband index figure, by rolling filamentousalgae around a stick, or, finally, with ascraper equipped with a razor blade or asmall scouring pad (available commercially,although you can also make oneyourself). Any rocks, sand, coral skeletons,branches, or roots infested by algaecan be treated, outside the aquarium, in a10% bleach solution, to which these algae• If due care isnot taken, microalgaecan rapidlycover the decorand panes of anaquarium. Thisdoes notnecessarily have anegative effect onthe fish, but thevisual effect isseriouslyundermined.193

PLANTSDIFFERENT GROUPS OF PROBLEMATIC ALGAERed algae (Rhodophyceae)It is unusual to find a proliferation of these algae in an aquarium.Brown algae (Pheophyceae)In an aquarium, these mainly consist of diatoms, unicellular microscopic algae. These grow and form a thin film on thedecor and glass panes of the tank. Under poor ecological conditions, they can follow from certain green algae.Green algae (Chlorophyceae)It is generally considered that their appearance in small, sparse clumps is a good sign (especially in alkaline water) thatmay indicate that the aquarium is well-equipped. However, if they proliferate they create two main types of problem:- green filamentous algae; this is probably one of the types of overgrowth most often seen. These algae are very thinand, although they sometimes only grow to a few centimeters in length, they can extend to several dozen centimeters.They reproduce through fragmentation, with one very short filament, invisible to the naked eye, sufficient to colonizean aquarium in a fairly short space of time, if the conditions are right;- green water; this is caused by the widespread growth of microscopic algae, generally unicellular, which can movearound with the help of a flagellum. In a natural setting, these constitute phytoplankton. They often proliferate rapidlywhen the concentration of nutritional elements (mineral salts), particularly nitrogen, is too high, in strong light.Blue algae (Cyanophyceae)Also microscopic, these are extremely ancient in origin: they were among the first living elements to appear on Earth.Despite their name, they form a green-blue, sometimes brownish, layer with a velvety sheen. They often develop if thelighting is excessive.are very sensitive. Any submerged equipmentcolonized by algae (heating, pipes,diffuser, filter) can be treated in the sameway. It is important to rinse and dry themthoroughly before putting them back intothe tank. Sometimes, however, the proliferationof algae can be so extensive thatthe only option is to create a whole newaquarium from scratch.using water with a low hardness containingfew mineral salts.A disposable razoris useful foreliminating algaethat grow on theaguarium panes.•194Ecological methodsTry to regulate the factor provoking thealgae overgrowth by adjusting the amountof light, which should be reduced in thecase of green or blue algae. Changing theposition of the tubes, or the addition ofdeflectors, to keep algae off the front ofthe tank, produces good results. In freshwateraquariums, you can make partialwater changes, on a fairly regular basis,

Be careful, however, not to make anydrastic alterations to the quality of thewater if this has been specially adjusted tospecific plants and fishes.In seawater tanks, change the water,replacing it with reconstituted water ofthe same salinity.Biological methodsThese can involve the use of herbivorousanimals only interested in certain types ofalgae, such as the fish mentioned aboveor gastropods (rare in sea water).The battle on the biological front is sometimesfought without any intervention onthe part of the aquarist, as larger aquaticplants release substances that can inhibitthe development of algae.The extent of this phenomenon is verydifficult to appreciate in an aquarium, asit is invisible to the human eye.Chemical methodsThere are special products on the marketdesigned to kill algae. As their effect hasnot been fully established, it is best to becautious with the dosage, as these substancesprobably also affect other plants.For the same reasons, the use of coppersulfate is not recommended, as it is dangerousfor invertebrates.There is no miracle solution. The use ofseveral techniques at the same time sometimeshas positive results, but it is notunusual to find that the algae reappearafter a while. It is best to get used to partiallyeliminating them on a regular basis.ALGAE PROBLEMSSeveral fish can be used in the biological battleagainst algae in fresh water: Epalzeorhynchussiamensis (right) and Gyrinocheilus aymonieri (left).195

CARING FOR PLANTSPlants need light, mineral salts (fertilizer), and carbon dioxide (CO 2 ) to grow,and their survival and reproduction depends on the right proportionsof these elements. A fishkeeper also needs to be an aquatic gardenerand have "green fingers" to cultivate his or her live decor.You must respectthe needs ofplants to obtainoptimal growthand reproduction.•Plants have anoverwhelmingneed for light,whether natural orartificial, to growand produceoxygen, once theyhave absorbedcarbon dioxide.196WHAT PLANTS NEEDWaterAquatic plants are in general very sensitiveto the water quality.Although some plants, such as the floatingfern, are easy to keep, and seem indifferentto the quality of the water, othersrequire water that is soft and acid or, alternatively,alkaline and hard, and will onlyflourish in water that is adapted to theirspecific needs.LightAquarium plants usually need strong lighting,produced by special fluorescent tubesfor 12 or 13 hours a day.For information concerning lighting seepage 226.If the lighting is deficient in either qualityor quantity, the plants will turn yellowand eventually die.Carbon dioxide (CO 2 ), oxygen (O 2 ), andphotosynthesisLike all living beings, plants are continuouslyrespiring. They consume oxygenand expel carbon dioxide, thereby affectingthe oxygenation of the water, both ina natural setting and an aquarium.By contrast, in reaction to light - thereforeonly by day - they absorb the carbondioxide from fish respiration and produceoxygen: it is this photosynthesis thatenables them to grow. This phenomenonhas a beneficial effect on the equilibriumof the aquarium, as it results in the productionof more oxygen than the plantconsumes in its respiration.There may be slight variations in the oxygenlevels from day to night, with theminimum levels being reached in the lastthird of the night. An aquarist (preferablyan insomniac!) can verify this by measuringthe pH every hour in a cycle of 24hours (see diagram on page 14).An increase in the water's oxygen levelpushes up the pH, while the productionof CO 2 at night acidifies the water and thepH goes down.MAGNESIUM, CHLOROPHYLL,AND IRONMagnesium is an important element, as itmakes up part of the chlorophyll pigment thatabsorbs light. Iron plays a role in the chemicalreactions of photosynthesis. If plants are deficientin iron, their growth slows down andthey turn yellow; specialists refer to this aschlorosis - a condition also seen in agriculture.

This phenomenon, which is only reallyvisible in heavily planted and denselypopulated aquariums, rarely entails anyproblems for fish.FertilizersWhen an aquarium is put into operation,the bed and the water contain mineralsalts. These gradually run out and theplants are therefore in danger of mineraldeficiency. Faced with this situation, anaquarist has three options:- regularly change part of the water (generally10% of the volume per week), toobtain "new" water containing salts;- add liquid fertilizers specially designedfor aquatic plants;- add solid fertilizers, in the form of sustained-releasemineral salt capsules placedat the base of the plants.You can also make a solid fertilizer athome, based on clay. Knead it, form smallballs, then have them soak up liquid fertilizer.Placed at the base of plants, theseballs gradually release their nutrients.Mineral saltsThis name covers all the substancesneeded for the growth of aquarium plants.They are in fact the equivalent of the fertilizersthat are used in agriculture, or forhouse plants.Plants' needs vary according to the substance:some are only required in tinyamounts (metals, for example) but theymust be constantly available. Mineral saltsare absorbed by the roots and leaves intruly aquatic plants, and by the roots inamphibian plants.In the natural environment, some aquaticareas are considered fertile, as therenewal of the water and the equilibriumof the natural cycles provide sufficientamounts of mineral salts for plants toprosper. Those regions lacking these vitalelements are characterized by sparse vegetation,or none at all.In an aquarium, which is a self-containedenvironment, the water and the bed containmineral salts that will gradually runout, at a rate determined by the quantityof the vegetation. You must thereforemake plans to reinforce the mineral saltlevel on a regular basis, as you would forCARING FOR PLANTSA FEW RULES FOR A NOVICE"AQUATIC GARDENER"1. Choose plants suited to aquarium water.2. Choose hardy species, some rapid growers and other slower.3. Satisfy their needs, especially as regards special lighting.4. Check the supply of nutrients.5. Do not hesitate to ask for advice, from your aquarium storeowner or from clubs and associations.A LACK OF CO 2There is usually enough carbon dioxide in thewater, but it can sometimes be deficient, evenin a tank that is profusely planted and well lit.If this occurs, the carbon dioxide that hasbeen trapped by the bicarbonates is used in itsturn: the pH often rises above 7.5, sometimeseven up to 8, in freshwater, and the calciumforms a fine layer on leafyplants and "suffocates"them. Deposits can alsobe seen on the glasspanes, at water level.Carbon dioxide diffusersare available in theaquarium trade to remedythis problem. Youmust also bear in mindthat aeration and stirringof the water, which contributeto its oxygenation,help expel the CO 2dissolved in the waterinto the atmosphere. Thismeans that excessive stirringcan sometimes havedire consequences forplants.Nowadays specialistaquarium stores stockequipment designed tosupply plants with theCO 2 they need. •house plants. Some aquarists provide,from the very beginning, an enriched soilthat will gradually release these mineralsalts. This is particularly useful when197

MINERAL SALTS REQUIRED BY PLANTS- Nitrogen, contained in nitrates.- Phosphorus, contained in phosphates.- Potassium, which is a component of other salts.A few other substances are also needed, sometimes in very smallquantities:- Metals, such as iron and magnesium (see page 196);- Vitamins.extensive planting is envisaged for theaquarium (in the case of a Dutch aquarium,for example - see page 33).Many aquarists treat plants as mere decorativeelements; others cultivate them inthe same way as they raise fish: they makethem grow and even reproduce. It is possibleto find veritable "aquatic horticulturalists"who obtain astonishing results.How do you know if your plants have agrowth problem?A plant lacking any of the elements itneeds to live turns yellow or brown andrapidly dies. The leaves get covered witha fine layer of filamentous algae and eventuallyfall off. However, in some species itis not easy to tell when the growth processis slowing down.Vegetation canthrive in anaquarium,if it isprovided withgood lighting andnutrient salts. •GENERAL CONDITIONS FORGROWING AQUATIC PLANTS198

REPRODUCTION OF PLANTSIn the wild, the most common mode of reproduction among plants is sexual, involvingflowers and seeds. When the conditions in a setting are inauspicious, however, sexualreproduction gives way to asexual reproduction, know as vegetative multiplication.Pieces of plants that have broken off or been uprooted, and then swept along by themovement of the water, settle and take root. It is this vegetative multiplication methodthat is used in aquariums. The techniques used, which vary according to the typeof plants, are similar to those of horticulture.TAKING CUTTINGSCuttings can be taken from astemmed plant, which is cut cleanlywith a razor blade or scissors. Theupper part, about one third of thelength, is replanted. Some aquaristsprefer to remove the leaves from thelower third of the cutting beforeplanting it, while others recommendleaving them in place, on thegrounds that they will gradually beconverted into mineral matter asthey are degraded. Roots form andthe new plant normally growsquickly. The lower part of themother plant produces lateral shootsthat can be used for cuttings lateron. Adventitious roots (those growingsporadically away from theirnormal location) make it easier totake cuttings from most stemmedplants (like Cabomba, Hygrophila).How to encourage cuttings?The upper part of a stemmed plantproduces substances that inhibit thegrowth of side shoots. If this sectionis cut off or firmly squeezed, thesesubstances do not reach the lowerpart of the plant, and lateral shootssuitable for cuttings can grow. Thistechnique is widely used when thestem of a plant reaches the surfaceof the water.To take cuttingsfrom a plant, cutthe upper part(top) and replant it(center). Thisprovides theopportunity forlateral shoots toemerge on theoriginal stem(below).To take a cuttingfrom a stemmedplant, it isadvisable to makea clean cut.Cuttings can be easily taken from most stemmedplants, provided a few precautions are taken. TA FEW HINTS FOR SUCCESSFUL CUTTINGSIf the lower part of a stemmed plant loses its leaves, this meansthat light is having difficulty in penetrating right to the bottom ofthe aquarium. In this case, cut the plant a few centimeters fromthe bed and transplant the healthy upper part.If you have small rearing tanks, these can be used as aquatic"greenhouses" for the cultivation of stemmed plants. It is best touse fertilizer, in the form of liquids or clay balls. Some fish need tobe added to ensure the supply of C0 2 to the plants. Aeration is notstrictly necessary, and filtration should be moderate.199

PLANTSDIVIDING THE BASEPlants without stems thicken at the base, sometimes forming smaller, secondaryfeet with roots. These can be carefully removed with a razor bladeand replanted.The division of the baseis a technique applicable tomany plants, such as thecryptocorynes.Marine algae ofthe Caulerpagenus multiply byextending arunner, whichsprouts new leaves200LAYERINGSome plants, such as theEchinidorus species or the marinealgae from the Caulerpa genus,produce a horizontal aerialstem, known as a runner (orstolon). A young plant thengrows out of this, producingroots that enable it to establishitself in the bed, either spontaneously,or with added helpfrom the aquarist, who mayhave to encourage it totake root. After about aweek, the roots will havegrown sufficiently to allowthe runner to be cut off. Inthe case of the Congo fern,this produces a rhizomethat grows slowly, withnew leaves appearing onit. If you cut off this rhizomebetween two leaves,you are left with two independentplants.A "REARING TANK"FOR PLANTS?Why not? Some aquarists sometimes manageto get plants to reproduce sexually,when they bloom. They use one or severalcultivation tanks, in which cuttings,layering, and division of the base are regularlyperformed. When they are fullygrown, the plants are then transplantedinto a community aquarium.A reproduction tank for plants must havespecially adapted and fairly strong lighting.Top right: Valliseneria and Sagittaria reproducespontaneously via runners (top). The new plantmust be made to take root (center) before cuttingthe runner (below).The water level should notbe too high, to assist thepenetration of light, and thebed should be given appropriateenrichment. Miniature jardinierescan even be constructed, using jars orice cream or yogurt cartons, forexample. The filtration should begentle, and there should beno oxygenation at all, toavoid the CO 2 dissolvedin the water being let offinto the atmosphere. Ifthere is not enough carbondioxide, equipmentto provide moderate diffusionof this gas into thetank is available inaquarium stores. A fewfish will add the finishingtouches to theequilibrium, and ifyou choose specimensfrom the samespecies, they can reproduceas well. These days many aquaristsare enthusiastic about the reproduction offish, but few are interested in cultivatingplants, although this can be just as fascinating.The propagation of aquatic plantsis easy and you can quickly build up largestocks to pass on to, or exchange withother enthusiasts.

AQUARIUM PLANTSOf the thousands of plants that are genuinely aquatic, or only amphibian,only a few hundred are to be found in the aquarium trade. The vastmajority of these come from tropical fresh water, with the remainder comingfrom northern climes, and therefore suitable for temperate aquariumsand garden ponds. The most common plants are generally the most robust,and are therefore specially suitable for beginners. Others are best left tocommitted aquarists keen to create a veritable aquatic garden. The specialplants - the floating species, mosses, and ferns - have beengrouped together, on account of their exceptional lifestyle; theyshould be of interest to all aquarists.

AQUARIUM PLANTSMOST POPULAR PLANTSThey could also be called "the classics," as they have given great pleasure to both veteran and noviceaquarists for generations. Some are of particularly interest to beginners, as they are not only easy tocultivate but also inexpensive.They are mainly stemmed plants which provide cuttings without any difficulty and grow rapidly providedthey are given the appropriate level of light. Some are species that adapt to different types of water, othersare more suited to a regional aquarium.Acorus (Araceae, Asia)The Acorus genus, native to temperate and cold waters, is widely distributed outsideits original breeding grounds. It will not tolerate temperatures over 22°C and istherefore exclusive to temperate aquariums. These plants reproduce by dividing arhizome between the buds. They are generally paludal (marsh plants) and are equallysuited to aquaterrariums and garden ponds, although they will also survive totallysubmerged.Acorus gramineusThere are two varieties of this species. The biggest, the green acorus, grows to aheight of 30 cm; the smallest, the dwarf acorus, at around 10 cm, is ideal inforegrounds.Acorus calamusThe sweet flag or muskrat root is found in Europe. As it can grow to a height ofover 1 m, it is reserved for garden ponds.Acorus gramineusBacopa carolinianaBacopamonnieri•Bacopa (Scrofulariaceae,southern United States, Central America)These hardy plants, with their paired oval leaves, can be made to flower in anaquarium, but taking cuttings is the best way to propagate. They prefer waterthat is neutral or slightly acid and not too hard, and are best planted in groups,with small spaces between their stems.Bacopa carolinianaThe hardy water hyssop tolerates temperatures as low as 20°C, but will notstand those above 24-25°C. Size: 30 cm.Bacopa monnieriThere is more space between the leaves than in the above species. Thesnowflake hyssop grows quite slowly and is very easy to keep but it requiresgood lighting. Size: 30 cm.202

• Cabomba aquaticaCeratophyllum(Ceratophyllaceae, cosmopolitan)Ceratophylls can be found all over the world, but onlyone species is common in aquariums.Ceratophyllum demersumThe water sprite is found in Europe and CentralAmerica, though this temperate water plant can adjustto tropical aquariums. It is well suited to tanks withgoldfish or garden ponds, where it can sometimesgrow in profusion. It is easy to cultivate, although itsstem breaks easily. It does not have any true roots andfinds it difficult to establish itself in the substrate; ittherefore has to be "wedged in" by rocks or branches,or float on the surface. It is easy to take cuttings fromthe main stem, or from side shoots. It is relativelyindifferent to the hardness and pH of the water, but itdoes require strong lighting. Size: 30-40 cm.MOST POPULAR PLANTSCabomba (Cabombaceae, southern United States, SouthAmerica)Some fish, such as South American Characins, take advantage of the finefoliage of the cabomba to lay their eggs, while other partially herbivorous fishgraze on it. These plants need good lighting, water that is not too hard, and amore or less neutral pH. Forreproduction take cuttingsfrom the side shoots, or fromthe top.Cabomba aquaticaIf the light is weak, the watercabomba spreads out on thesurface of the water. It growsquickly, unless the water islacking in carbon dioxide; thismeans that you must avoidcirculating it too vigorously.Size: 30-40 cm.Cabomba carolinianaMore robust than its cousin, thefish grass or water shield cantolerate temperatures of 20°Cbut its soil must be fairly rich.The form of its leaves dependson the conditions under which itis cultivated. Size: 30-40 cm.Ceratophyllum demersum• Cabomba carolinianaElodea and Egeria (Hydrocharitaceae, cosmopolitan)These are known as water pests, on account of their tendency to proliferate.Under an intense light they produce a great deal of oxygen. They put downroots but can also live afloat, preferably in hard, alkaline water.Elodea canadensisOriginally from North America, Canadian pond weed has been introducedinto temperate regions all over the world, although only the female has beenpresent in Europe since the middle of the 19th century, and it can obviouslyonly reproduce through cuttings. It is a plant for temperate aquariums orgarden ponds, with an optimum temperature range of 15-20°C.Egeria densa (formerly Elodea densa)Both sexes of the dense elodea were, similarly, introduced into Europe,although it is highly unusual to find reproduction through flowering in anaquarium. It is suited to temperate aquariums, but can tolerate temperaturesof up to 25°C. Size: 30-40 cm.Egeria densa203

AQUARIUM PLANTSEleocharis (Cyperaceae, tropical regions)These plants, resembling tufts of grass, live in swamps, and are therefore suited toaquaterrariums, although they can also be cultivated in aquariums under stronglighting, in hard, alkaline water.Eleocharis minimaWhen the stems of the spiked rush reach the surface, they spread out and do notemerge above it. Vegetative multiplication occurs with the help of runners or thedivision of a clump. Size: 20-30 cm.Heteranthera (Pontederiaceae, Central or South America)These plants are totally aquatic, requiring intense light and a fairly rich soil. They aresensitive to any deficiency in iron. The water must be slightly alkaline andmoderately hard.Heteranthera dubiaThe yellow-flowered heteranthera can be reproduced with cuttings, a processthat is facilitated by adventitious roots on the stem. The stem is quite fine and canfloat on the surface of the water. Size: 40 cm.Heteranthera zosterifoliaThe stargrass can live totally submerged. It multiplies through cuttings of the sideshoots; it can also grow as a creeper. Size: 30 cm.• Eleocharis vivapara, a species closely relatedto Eleocharis minima• Hygrophila guianensisHygrophila(Acanthaceae,South-East Asia)More than 10 species are foundin the aquarium trade, althoughthe existence of different varietiesand the modifications made to scientific names can lead toconfusion. They live half-submerged, but can tolerate immersionin a moderately hard acid or neutral water. They need intenselight to grow well, and should be planted in groups, butwith sufficient spaces between the stems. It is easy to takecuttings: just chop off the head of the stem as soon as itreaches the surface.Hygrophila corymbosa (formerly Nomaphila)The giant hygro tolerates temperatures as low as15°C. The presence of adventitious roots is anadvantage when taking cuttings. Size: 30 cm.Hygrophila guianensis (formerly H. salicifolia)The willow leaf hygro, recognizable by an almostsquare stem, is sensitive to excessively hard water or alack of iron. When the light is insufficient, the leaves atthe bottom of the stem fall off. Size: 30 cm.Hygrophila difformis (formerly Synnema triflorum)Considered a weed in its native region, the water wisteria isprized by aquarists for its pale color and finely serratedleaves, although when these first appear their form is lessdelicate. This plant tolerates fairly wide ranges of hardnessand pH. When the leaves drop off the stem, young shootsappear in their place. Size: 30 cm.Hygrophila difformisHygrophila corymbosa204

MOST POPULAR PLANTSLimnophila (Scrofulariaceae, South-East Asia)Its fine foliage is much appreciated by certain fish which lay theireggs on it or, depending on the species, munch on it. Theseamphibian plants can live submerged, and when they reach thesurface of water they spread out on top of it. At this pointcuttings should be taken and transplanted. Good lighting isessential. A lack of iron causes their leaves to turn yellow.Limnophila aquaticaThe aquatic ambulia grows well in soft or slightly hard and acidwater, providing it has an adequate supply of mineral salts. Smallshoots from its base are perfect for cuttings, although removingthe top is equally effective. This ambulia must be planted inclumps, with the stems slightly separated to take advantage of thelight. Size: 30 cm.Limnophila heterophyllaThe heterophyllous ambulia is less tufted than the above, but itstips must nevertheless be removed regularly. Size: 30 cm.• Limnophila heterophyllaLudwigia (Onagraceae, tropical regions)Ludwigs thrive on light, iron, and fairly rich soils. Cuttings are takenby lopping off a stalk under the adventitious roots. Another optionis to cut off the top of the plant, which avoids the loss of any of thelower leaves. Size: 30 cm.Ludwigia ascendensThe totally aquatic large-petaled ludwig can sometimes appearabove the surface. It tolerates a wide range of hardness and a pH ofaround 7. It is especially recommended for beginners.Ludwigia alternifoliaAs its name indicates, the leaves of the alternate leaf ludwig arearranged alternately along the stem, and not directly opposite eachother. It prefers soft, acid water. Size: 30 cm.Ludwigia brevipesA fairly resistant plant, the false lusimakhos tolerates hard, alkalinewater and temperatures slightly below 20°C. It can therefore be usedin a temperate aquarium. Size: 30 cm.Ludwigia repensThe rampant ludwig is found in both a green variety and a reddish variety. Both requiregood lighting but are considered hardy. Size: 30 cm.• Ludwigia sp.Ludwigia repens Myriophyllum aquaticum •Myriophyllum (Haloragaceae, North and SouthAmerica)Around a dozen species from this genus, both amphibian andtotally aquatic, constitute some of the most popular aquariumplants. Their soft foliage is appreciated by fish with herbivoroustastes, while others use it to lay their eggs. The aquatic milfoilsthrive on light and relatively hard water, although this must beclear, as small suspended particles get trapped in the foliage. Themain method used for reproduction is that of taking cuttings.Myriophyllum aquaticumIn contrast with the other species, the water milfoil prefers soft,acid water. Cuttings are taken by removing the top or the tinybranches. You can achieve a stunning decorative effect byplanting a copse of these plants. Size: 40 cm.Myriophyllum spicatumThe spiked milfoil is a hardy, fast-growing plant that needs fairlyhard alkaline water. It must be pruned regularly to ensure that itremains sturdy. Several other species of milfoils are available onthe market, some with reddish hues; they all require goodlighting. Size: 40 cm.205

AQUARIUM PLANTSRotala (Lythraceae, South-East Asia)The leaves of these species are reddish in color, especially on the underside, but theirshape varies according to the setting. They grow in soft, acid water, under stronglighting, and need plenty of iron. The formation of adventitious roots makes it easy totake cuttings. They can produce a striking visual effect if they are planted in a grove,as they stand out well against green plants.Rotala macrandraThe coloring of the giant red rotala varies according to the intensity of the lighting,but, as is name suggests, red usually sets the tone. It grows quite quickly, but pruningencourages the growth of lateral shoots which can be used for cuttings. Size: 30 cm.Rotala rotundifoliaThe upper face of the leaves of the round-leaf rotalia is green, the lower one areddish color. When the leaves emerge from the water they turn completely green.It is beautiful in clumps, though you must leave sufficient spaces between the stemswhen planting. Size: 30 cm.Rotala rotundifolia• Sagittaria sagittifoliaRotala macrandaSagittaria (Alismataceae,North and South America, andEurope)The leaves of these paludal plants that areabove water are arrow-shaped, while thesubmerged ones take the form of thin ribbons.Take care not to push the rhizome too far intothe soil: the plant can be held in place by acurved piece of wire. Vegetative multiplicationoccurs by means of seedlings formed on arunner, which can took root on their own, orwith the help of the aquarist. The runner canthen be cut off.Sagittaria gramineaThere are several varieties of the narrow leafarrowhead, which differ in the length andwidth of their leaves. They all prefer moderatelighting, soft or slightly hard water, and anapproximately neutral pH. Size: 40 cm.Sagittaria sagittifoliaThe amphibious arrowhead is quite commonin calm waters in Europe, especially in gardenponds, where it resists the winters, although itprefers sunny areas. Size: 40-50 cm in water.Sagittaria graminea •HOW TO DISTINGUISH BETWEEN SAGITTARIAS AND VALLISNERIASSagittarias and vallisnerias can be distinguished by the tips of their leaves.SagittariasThe longitudinal veins do not reachthe tip. The transversal veins are perpendicularand numerous.VallisneriasThe longitudinal veins reach the tips. Fewtransversal veins, sometimes at obliqueangles.206

PLANTS FOR THE MORE EXPERIENCEDVallisneria (Hydrocharitaceae, Asia)The vallisnerias are often confused with the sagittarias. Like them, they reproduce throughrunners, need plenty of light, water that is not too hard, and a slightly acid pH.Vallisneria asiaticaThe eel grass is found in severalvarieties. Its leaves are spiraled. It canexceed 40 cm in height, which makes itideal for decorating the sides or rear of anaquarium. Size: 40-50 cm.Vallisneria spiralisThe term spiralis refers to the floral peduncleand not the leaves. The spiraled eel grass isvery popular in aquariums and reproducesactively under good conditions. Size: 40-50 cm.Vallisneria giganteaIts leaves, which can grow to 1 m in length and 3cm in width, rest on the surface of the water. Thegiant vallisneria prefers intense lighting and aslightly enriched soil. It is obviously only suitable forlarge aquariums. Size: 1 m.Vallisneria giganteaVallisneria spiralis •PLANTS FOR THE MORE EXPERIENCEDOnce you have gained experience with the above species, you can move on to other less commonplants. Those that take the form of tufts tend to grow quite slowly, which may be frustrating for moreimpatient aquarists. However, they are a beautiful sight if their requirements are satisfied, especially withrespect to the water quality and the intensity of the lighting.Alternanthera (Amaranthaceae, South America)These plants prefer soft, acid water and multiply with the help of cuttings. Theirreddish color stands out among the other plants in an aquarium.Alternanthera sessilisThere are two varieties of sessile alternanthera. The first, with totally red leaves,does not last for more than a few months if it is fully submerged. The second canbe distinguished by the brown-green coloring of the upper part of the leaves, andcan adapt more easily to atotally aquatic life.Size: 30-40 cm.Alternanthera reineckiiMore hardy than the abovespecies, Reineck'salternanthera is not so eyecatchingas it does not sharethe red coloring. It produceslateral shoots under intenselighting, which make it easy totake cuttings.Size: 30-40 cm.Alternanthera reineckii Alternanthera sessilis207

AQUARIUM PLANTSAnubias (Araceae, West Africa)These grow slowly, under weak lighting, in soft, acid water.Multiplication takes place through a division of the rhizome,which must never be covered with soil.Anubias barteriThere are two varieties: the smallest, the dwarfanubias, is ideal for foregrounds; the biggest,Barter's anubias, has spear-like leaves and canbe placed a little further back. Size: 30 cm.Anubias heterophyllaThe Congo anubias can exceed 35 cm in height and istherefore only suitable for large aquariums. The shape of theleaves can vary considerably but, broadly speaking, they are ovalor lanceolate. Size: 30-40 cm.• Anubias barteriCryptocoryne cordata •Anubias heterophyllaCryptocoryne (Araceae, South-East Asia)Several dozen species of this genus are used in aquariums, which sometimesgives rise to confusion. Some are genuinely aquatic, others amphibious. Thequality of water required varies according to the species: soft to moderatelyhard, slightly acid to alkaline; the soil must always be quite rich. Sexualreproduction with flowers is rare; vegetative multiplication occurs by meansof runners or the division of the clump.Cryptocoryne balansaeBalansa's cryptocoryne prefers intense light and a temperature over 25°C.It should be kept as a single specimen, to highlight it. Size: 40 cm.Cryptocoryne beckettiiBeckett's cryptocoryne, paludal in the wild, is very resistant and can livetotally submerged. Size: 40 cm.Cryptocoryne ciliataThe ciliated cryptocoryne is one of the species in this genus that tolerateshard water, and it requires fairly rich soil. It is amphibious in its naturalenvironment. Size: 40 cm.Cryptocoryne cordataThe Siamese cryptocoryne exists in several varieties, whichdiffer from each other in the shape of their leaves. It adjustswell to hard water. Size: 15-20 cm.Cryptocoryne crispatulaA large hardy species, the undulated cryptocoryne isreserved for big aquariums, where it deserves to beshown off. It dislikes water that is too hard.Size: 50-70 cm.CryptocorynebeckettiiCryptocoryne crispatulaHottonia inflata •(foreground)208

Echinodorus (Alismataceae, South America)Most echinodorus are paludal plants, but they can also survive underwater.The shape of the leaves depends on the conditions under which they arecultivated, which can range from slightly acid to neutral water, and low tomoderate hardness. These plants turn yellow when they lack iron, so you mustensure that there is an adequate supply. You can reproduce them by taking acutting of a rhizome on which seedlings have appeared.Echinodorus amazonicusUnder good conditions (moderate to strong lighting), the Amazon grows to40 cm. If the water is too hard it is markedly smaller and appears to stopgrowing.Echinodorus maiorThe giant echinodorus reaches the same height as its Amazonian cousinand, like it, is worth highlighting in a large aquarium if it is the onlyr epresentative of its species. Size: 30-40 cm.Echinodorus quadricostatusThe dwarf Amazon serves to decorate the foreground of anaquarium. It prefers a moderately rich soil, and toleratestemperatures under 20°C. The shape of the leavesvaries according to the lighting. Size: 10 cm.Echinodorus tenellusThe pygmy Amazon, the smallest of the genus,prefers soft water. It can rapidly accumulate anextensive covering of runners. It does not like toomany fine muddy particles round its base.Size: 10 cm.PLANTS FOR THE MORE EXPERIENCEDEchinodorus tenellusEchinodorus amazonicusEchinodorus sp.Hippurus (Hippuridaceae,cosmopolitan)These plants are found in the temperateregions of the northern hemisphere. Theyare most common in garden ponds.Hippurus vulgarisIts aerial leaves differ in shape from thoseunderwater. The water spruce can becultivated in a tropical aquarium. Size: under50 cm submerged, 10-15 cm above water.Hottonia (Primulaceae, CentralAmerica)Some species from this genus arenative to the northern hemisphere,and so they can resist watertemperatures down to 15°C.Hottonia inflataA totally aquatic plant with finelyserrated leaves, the featherfoil likes soft,acid water. Adventitious roots on the knotsof the stem make it easy to take cuttings. Itis highly attractive when planted in groups.Size: 20-30 cm.Lobelia (Lobeliaceae,North America)The plants in this genus, native to tropicalregions, are either terrestrial or paludal.One of the latter types can adjust totropical aquariums, although it grows veryslowly.Lobelia cardinalisThis amphibious plant can resisttemperatures of 10-20°C in moderatelyhard, approximately neutral water. Thecardinal flower is appropriate fortemperate or tropical aquariums, though itrequires intense light in a tropical tank. Itmultiplies by means of cuttings.Size: 30 cm.Lobelia cardinalis209

AQUARIUM PLANTSSPECIAL PLANTSThese plants are not rooted and complement the classic vegetation on both the aesthetic and ecologicalfronts, floating plants provide shade and shelter for fry; mosses are used by some fish to lay theireggs, and slow-growing ferns colonize solid supports. Moreover, floating plants are renowned for thespeed with which they grow.Bolbitis (Lomaropsidaceae, Africa and Asia)These ferns live either wholly or partially submerged. One speciesis particularly popular among aquarists.Bolbitis heudelotiiThe species from this genus most often found on the market, is atrue fern and its rhizome must never be buried as it naturallyattaches itself to a support (such as a rock, root, or artificialdecor). This attachment can be temporarily encouragedby tying the rhizome with nylon line, or wedging itbetween small stones. It grows slowly and requiresnormal lighting, water of a moderate density, and apH of around 7. It can be made to reproduce bycutting off the rhizome when new shoots appear.Size: 20-30 cm.Ceratopteris cornuta (Parkoriaceae, cosmopolitan)This floating fern makes an ideal shelter for new-born fry, or asupport for the bubble nests of the Belontiid family. It growsquickly under strong lighting: when it takes root - which it doeswith ease - its coloring turns paler and its leaves change shape.Ceratopteris thalictroidesThe Sumatran fern prefers to berooted, but it can also survivefloating, though its leaves growthicker. It is a fast-growing,hardy species. Size: 50-60 cm.Lemna(Lemnaceae,cosmopolitan)Water lentils float on the surface and grow very fast. Ifthey are introduced into a tank, either deliberately oraccidentally, they can colonize the entire surface, sothey must be eliminated regularly.Lemna minorThe duckweed is often confused with L. gibba, but itsleaves do not exceed 1 cm in length. It can be used toprovide shade in one part of the aquarium, or a refugefor fry. Size: around 1 cm.CeratopteristhalictroidesMicrosorium pteropusLemna minorMicrosorium (Polypordiaceae, South-East Asia)This genus includes ferns with a clear predilection for humid environments. Only onespecies is of any great interest to aquarists.Microsorium pteropusThe Javan fern grows slowly, under moderate to intense light, but it is very hardy. Like allferns, it can reproduce sexually with spores, but vegetative reproduction is much morecommon in an aquarium. The rhizome can be cut off when young fronds appear, and canattach itself to a support with the help of small roots. This process can be encouraged bywedging the rhizome between stones - taking care not to squash it - or tying it downwith a nylon line. Size: 15-20 cm.210

SPECIAL PLANTSTRUE TERRESTRIAL PLANTS ANDFALSE AQUARIUM PLANTSSome house plants that require plenty of humidity, such asAglaonema, Dracaena, and Chlorophytum, are sometimes soldas aquarium plants. They do not last very long when they arecompletely submerged, but, at a pinch, they can be put into thebank of an aquaterrarium. They are usually bicolored, withleaves combining green with either red or white. You arestrongly advised not to buy them for an aquarium.Riccia fluitansRiccia (Ricciaceae, Europe, North and SouthAmerica, and Asia)Single specimens of these plants are tiny (1-2 mm), but they spreadto form a floating carpet. They grow quickly, especially under stronglighting, and so they must be cleared on a regular basis.Riccia fluitansThe floating riccia provides shelter for fry, and a breeding ground for the infusorians thatoften constitute their first food. This plant prefers moderately hard water, with a pH ofaround 7.Pistia (Araceae, tropical regions)The Pistia genus appears to contain only one species. It is a floating plant which grows ratherslowly, but it is of great interest to aquarists.Pistia stratoitesThe leaves of the water lettuce have a velvety sheen. This plant needs strong lighting togrow and for seedlings to form on the runners. It provides an aquarium with shade and arefuge for fry. It is badly affected by drops of water formed by condensation on the lid of thetank. Diameter: 5-6 cm.Salvinia auriculataPistia stratoites •• Vesicularia dubyanaSalvinia (Salviniaceae, South America)Despite their distinctive appearance, the salvinias are floatingaquatic ferns. The leaves are usually rough and arranged on eitherside of a floating horizontal axis. They reproduce by means ofrunners, and can rapidly invade a tank, although they are sensitiveto drops of condensation falling from the lid.Salvinia auriculataThe floating leaves of the salvinia are more than 1 cm long,which distinguishes it from the closely related, and otherwisebiologically identical, S. minima. If the lighting is good, it growsquickly in neutral, soft water. It is recommended as a haven forfry in rearing tanks. Size of a floating leaf: 2 cm.Vesicularia (Hypnaceae, South-East Asia)This genus includes a large number of species native to continentaltropical regions. Most are terrestrial, while some are amphibious oraquatic.Vesicularia dubyanaJavan moss is very popular among hobbyists as it attaches itselfto all types of decor, whether artificial or natural (wood, rocks).When introducing it into an aquarium you can help it to establishitself by wedging it with small rocks or pieces of wood. It likessoft, acid water, with moderate lighting. It offers an excellentsupport for the eggs of certain fish, as well as a shelter for fry. Itcan sometimes be invaded by filamentous algae. A close species,Bogor's moss (Glossadelphus zollingeri), is also on the market.211

AQUARIUM PLANTSSaururus (Saururaceae, North America)The vegetative reproduction of these plants can be achieved by taking cuttings or dividingthe rhizome. They live in marshy areas and so are often only partially submerged.Saururus cernuusLeiden's plant can acclimatize toan aquarium: it is not fussy about waterquality, but it does need plenty of light. Thispaludal plant is hardy and grows slowly; it ispossible to take cuttings from the stems.Size: 40-50 cm.A Saururus cernuus• Spathiphyllum wallisiiSpathiphyllum (Araceae, South America)These are amphibious plants that can be cultivated in flowerpots. Their leaves aresturdy and their growth is slow but regular.Spathiphyllum wallisiiThe spathy usually dies within a few months if it is permanently underwater. However,some aquarists manage to keep them alive for longer periods, without any apparentexplanation. Nevertheless, it is best to cultivate this plant partly outside water - whichshould be soft and slightly acid - for a few months if you have kept it totally submerged.Size: 40 cm.PLANTS FOR THE AQUATIC GARDENERLess commonly available (and often too expensive for many aquarists), these species demand theutmost respect for their requirements. The cultivation conditions for some of them are quite unusual,and they need a long "wintering" period every' year. You should have extensive experience ofaquatic plants before tackling these specimens, otherwise you might be rapidly disappointed.If they are set off well, these plants can quickly becomer the focus ofattention in a tank, particularly in Dutch aquariums.Aponogeton (Aponogetonaceae, Africa, Madagascar, and Sri Lanka)These very beautiful plants are by no means easy to keep in an aquarium, as they have topass through a "wintering" period lasting a few months, at a temperature of around 15°C.Their bulbous rhizome, with no leaves, must be kept in a separate tank in shallow water. Afterwintering, the water level and temperature are increased. The aponogetons like strong lighting andmoderately hard water. Sexual reproduction with flowers is possible in an aquarium. Vegetativemultiplication occurs if the rhizome is divided, and buried once leaves and roots have appeared.Aponogeton crispusA. crispus grows quite quickly. Like the other species of this genus, it looks best if it is grown as asingle specimen, highlighted against other plants. Size: 40-50 cm.Aponogeton ulvaceusWith its wavy, translucid leaves this specimen isconsidered to be one of the prettiest aquarium plants.Size: 40-50 cm.Aponogeton madagascariensisThe leaves of the Madagascar laceleaf consist ofveins, which give it a striking appearance but alsomake it especially vulnerable to invasions byfilamentous algae.It is often sold under the namesAponogeton fenestralis orAponogeton henkelianus, but hasa reputation for being difficult tocultivate. Size: 40-50 cm.Aponogeton ulvaceusAponogeton madagascariensisAponogeton crispus212

• Crinum sp.Eichhornia (Pontederiaceae,South America)This genus includes both submergedand floating paludal plants. They arerarely found in aquariums, but aresuitable for garden ponds.Eichhornia azureaWhen the azure water hyacinthis submerged, its fine leaves areround at the tips. It needs softwater and good lighting. It can bereproduced by means of cuttings.Size: 40 cm.Eichhornia crassipesThis magnificent floating waterhyacinth, ideal for garden ponds,has also been successfully introducedinto many tropical areas to purify thewater, as it gobbles up nitrates. However, inlarge bodies of water it grows so profusely that it hascaused problems for boats, although there are plans toalleviate this by producing methane from waterhyacinths through fermentation. Size: 10 cm.PLANTS FOR THE AQUATIC GARDENERBarclaya (Nymphaeaceae, South-East Asia)The Barclaya genus contains only three species, all native to South-East Asia.Although the relationship is not immediately apparent, the barclayas areclosely related to water lilies and are included in the same family.Barclaya longifoliaThe only species found in the aquarium trade, Barclaya longifolia, demandsstrong lighting - otherwise its leaves will remain small - and a neutral orslightly acid, barely mineralized water. Growth can slow down during thewintering period, but new leaves appear afterwards. It is difficult to make itreproduce by cutting the rhizome, and so it is best to wait for young leaves tosprout. This plant needs to be kept on its own to highlight its distinctivecoloring. Size: 40 cm.Crinum (Amaryllidaceae, Asia, Africa, and South America)There are several species of crinums scattered round the tropical regions of theworld, and all have a bulb. Only one of these, native to West Africa, isavailable to the aquarium trade.Crinum natansThe aquatic crinum is hardy and can reach a height of 1 m when its growthis enhanced by intense lighting and hard, alkaline water. Size: 50 cm.Eichhornia crassipesEichhornia azureaNymphaea (Nympheaceae, South-East Asia, Africa)The nymphaeas, better known as lotuses, are basically pond plants: one plantcan sometimes cover up to 1 m 2 . Two species can be kept totally submerged inan aquarium. Size: up to 50 cm under water.Nymphaea lotusThere are two colored varieties of lotuses: one is predominantly green, theother mainly red. It must be kept in fairly soft water, with a covering offloating plants to provide shade. The leaves that reach the surface must be cutto enhance the growth of the ones underneath the water. When itreproduces, young plants appear on the rhizome shoots. Diameter: 50 cm.Nymphaea rubraThis species has exactly the same requirements and biological characteristics asN. lotus, but has a strong purple coloring. The purple lotus therefore standsout dramatically when surrounded by green plants. Size: up to 50 cm underwater.Nymphaea lotus213

AQUARIUM PLANTSCLASSIFICATION OF PLANTS ACCORDING TO THE TYPE OF AQUARIUMTYPE OF AQUARIUMSUITABLE PLANTSNorth and Central America(water slightly hard and alkaline)South America(soft, acid water)West Africa (variable water characteristics)Asia and South-East Asia(slightly soft, acid water)Madagascar (moderate hardness)Cosmopolitan plants, relatively indifferent to water qualityPlants for temperate water aquariumsPlants for pondsPlants for aquaterrariumsBacopa, Cabomba, Heteranthera, Hottonia, Ludwigia,Myriophyllum, Sagittaria, SaururusAlternanthera, Cabomba, Echinodorus, Eichhornia,Heteranthera, Myriophyllum, SalvlniaAnubias, Bolbitis, Crinum, NymphaeaAcorus, Bardaya, Cryptocoryne (some species in hard, alkalinewater), Hygrophila, Llmnophlla, Microsorium,Nymphaea, Rotala, Vallisneria, VesiculariaAponogetonAcorus, Ceratophyllum, Ceratopteris, Elodea, Egeha, Eleocharis,Lemna, Ludwigia, Pistia, RicciaAcorus, Ceratophyllum, Elodea, Egeria, Hippurus, Lemna, RicciaEichhornia, Elodea, Egeria, Hippurus, Lemna, Sagittaria sagittifoliaAcorus, some Cryptocorynes, Eleocharis, Hippurus, Lemna,Microsorium, Nymphaea, Pistia, Riccia, Salvinia, VesiculariaMARINE VEGETATION IN AQUARIUMSNo plants are found above the water (or with flowers) in a marine tank; only a few algae can be cultivated,but the results can often be highly attractive. Unlike the undesirable microscopic or filamentousalgae, these species can be quite big and do not present any problems. These hardy plants take innutrients over practically all their surface area.Mediterranean algaeSome species native to the Mediterranean coasts canacclimatize themselves to tropical aquariums. If you removethem from their natural setting, it is advisable to take not onlythe alga but also part of its support, usually a rock.Codium bursa (Codiaceae)The felt ball codium forms a sphere with a diameter that canexceed 25 cm. It grows very slowly and the biggest specimensunfurl. This species likes strong light.Codium vermilara (Codiaceae)Its felt-like appearance and bottle-green color are thedistinguishing features of the felt codium. This species preferswell-lit areas. Size: 20 cm.Halimeda tuna (Udoteaceae)The Halimeda likes a murky environment and grows morequickly when the temperature is high, provided this does notexceed 25-26°C. Size: 1-10 cm.Udotea petiolata (Udoteaceae)Like the above, the udotea prefers poorly lit settings andgrows on sand or rocks. Size: 3-20 cm.214Halimeda tuna (in the foreground)

Ulvas and enteromorphs (Ulvaceae)These algae are common on European coasts. They do not last for long in anaquarium, but are useful as food for marine fish with herbivorous tendencies.The ulvas or sea lettuces (several species belonging to the Ulva genus) resembletranslucent lettuce leaves. Leaf size: 25-30 cm.The enteromorphs are filamentous, also translucent, and pale green (Enteromorphagenus, several species). Size: 40-50 cm. It is worth noting that in the wild Ulvaceaethrive in areas rich in nitrates.MARINE VEGETATION IN AQUARIUMSCaulerpas(Caulerpaceae)The caulerpas are green algae (Chlorophyceae) found in the tropics. There are severaldozen species, but only a few are found in aquariums. They consist of a filamentousrunner, which attaches itself to a support by means of rhizoids (or anchoring feet).The fronds extend from these rhizomes, their shape varying according to the species.Caulerpas grow quickly in an aquarium; the runner can sometimes increase its size byseveral centimeters per week.• Ulva and EnteromorphaCaulerpas like moderate lighting and clear, well-circulated water.Vegetative multiplication takes place through the division of therunner, where young fronds appear. In addition, a fragment ofthis alga can give rise to a small seedling. Sexual reproduction israre in an aquarium.Caulerpa proliferaThe Mediterranean caulerpa is found not only in theMediterranean but also in other temperate regions around theworld. The frond takes the form of an narrow, elongated leaf. It isvery adaptable, as it tolerates temperatures of 14-30°C, and istherefore suitable for temperate marine aquariums. Size: 10 cm.Caulerpa sertularoidesThe feathery caulerpa grows just as rapidly. The shape of thefronds varies according to the setting and, most especially, thelight. Size: 15 cm.• Caulerpa sertularoidesCaulerpa prolifera (full leaves)and C sertularoides withHippocampus kudaTHE TROPICAL CAULERPA ARRIVES IN TEMPERATE WATERSIt was thought that tropical caulerpas could not tolerate northern climes (around10-23°C). In 1984, however, the Caulerpa taxifolia species was found off the coast ofMonaco, occupying a few square meters. Since then it has proliferated wildly and,according to some estimates, now covers over 80 km 2 in the Mediterranean, stretchingfrom the Spanish island of Majorca to Croatia. Furthermore, the plant grows up to sixtimes the size found in the tropics!The morphology of C. taxifolia is similar to that of C. serularoides, and it grows quickly,often to the detriment of other plants, particularly Posidonia oceanica, a genuine butincreasingly rare flowering plant. C. taxifolia contains toxins that could cause food poisoningin humans, although no case has yet been reported. This is logical, as this alga isonly eaten by a few fish, and these are not eaten by humans. The caulerpa invasion canbe held in check - at the moment it seems impossible to eliminate it completely - bysending down divers to collect it by hand or with suction pumps, but this involves vastexpense. Other solutions proposed include releasing copper ions toxic to these plants,dumping tons of salt on them, or sending in a fleet of caulerpa-eating snails. A hugeresearch program is underway to evaluate the propagation, distribution, and influenceof this alga in the Mediterranean. Where does it come from? The aquarist communityhas been blamed, on the assumption that it was accidentally thrown into the sea, but(like other tropical algae) it could also have been introduced on ships' anchors and hulls.This invasion shows that certain species, especially the tropical ones, can survive elsewhere,and so aquarists must be careful when they throw out water; in any case, it isbest not to use this alga in aquariums, the other two species being good alternatives.215

TechniquesCreating an aquarium and putting it into operation do notdemand any great expertise. These days even novice aquaristshave easy access to a wide variety of techniques. Choosing theright equipment and understanding the basic rules will enable youto get the most out of your aquarium.

ASSEMBLING A TANKIf an aquarist is unimpressed by the range of aquariums on the market, then there is alwaysthe alternative of constructing a home-made tank. This requires only patience andprecision: the most important thing is to follow the sequence of operations. The hobbyist thushas the chance to choose a tank according to his or her requirements or the setting withinwhich it will be placed.unit and lighting hood. The supportingfurniture often has shelves or closets thatserve to hide the pumps and other equipment,and the aquarium is framed by decorativeelements that leave it visible fromthree sides.• An aquariumcan only be fullyappreciated whenit is integratedinto itsenvironment.218THE AQUARIUMDifferent modelsAquariums come in various shapes andsizes so that they can fit into the interiordesign of any home.Traditionally, most tanks take the form ofa horizontal rectangle, but these days it isalso possible to find cubes, vertical rectangles,or panoramic aquariums, all speciallyadapted to a specific setting.The basic model - and the cheapest -consists of a tank with a lid. It is also possibleto equip it with a lighting hood.There are other models with an integralhood and minimal external decoration,i.e. a strip, of varying widths, that goesround both the base and the top, hidingthe surface of the water. This type ofaquarium can be sold on its own or witha support. It can sometimes be fitted witha filtration unit. Finally, in the top range,there are aquariums built into a piece offurniture, normally containing a filtrationMaterialsCommercial aquariums are almost alwaysmade of glued glass, with silicone joints.These materials are suitable for water volumesof around 500 liters - volumes rarelyexceeded in the aquarium trade.The generalized nature of the materialsand the relative simplicity of the gluingmean that any careful hobbyist can builda glued glass aquarium him or herself.For bigger volumes, polyester resin orcement are used, with only the front partof the tank made of glass. These are thematerials found in public aquariums.Plexiglas, which is light but also scratcheseasily, is used for the rarer round forms.Small plastic tanks are also available foruse as rearing or quarantine tanks.DimensionsThe most harmonious form is obtainedwhen the length is equal to the height multipliedby 1.5-2.5. The height will beslightly greater than the width, except inbuilt-in tanks, where the contrary is thecase. These proportions can be adhered toup to a length of 1.5 m, but they are impossibleafter that, as the height must neverexceed 0.5 m (see table).It is not advisable to use very narrow aquariums,as a trick of the eye means that a tankseems one-third narrower when it is filledwith water, producing an unfortunate visualeffect. Narrow tanks can be attractive, however,if they are put on narrow pieces offurniture, such as a mantelpiece or a divid-

ASSEMBLING YOUR TANK"Diamond" tank.An original shapeproviding a strikingvisual effect. (LaRochelle Aquarium)ing wall between two rooms. It is alsoimportant to take into account the weightof the tank. A solid support is required,because an aquarium is heavy when it isput into operation: the weight of the waterand decor must be added to that of thetank itself.PositioningAn aquarium must be positioned withcare, as once it is filled it will be impossibleto move it anywhere else. It is a complicateddecision, involving the visualimpact on the room, practical considerations,and ecological criteria.• Visual impactObviously, a big tank fits better into alarge room, and a narrow tank into a smallroom. Choose a fairly dark spot to highlightit, well away from the television, toavoid any competition between these twocenters of attention.An aquarium traditionally has its longestdimension set against a wall, but there areother ways of setting it off. It can occupya corner, be placed on a partition betweentwo rooms, or be built into a wall.• Practical considerationsYou must plan on having an electricalDIMENSIONS, VOLUMES, AND WEIGHTSYou must consider the gross volume (that of an empty aquarium) the net volume (when the tank isfull, the sand and decor take up a certain amount of space) and the final weight of the aquariumwhen in operation. This depends on the bed and the extent of the decor; as these vary from onetank to another, the weight is therefore only indicated as a rough guide.219

and in this way children will also be ableto see it without any problem.• Ecological criteriaIt is essential that sunlight, especially thatcoming from the south, does not strike theaquarium directly, as there is a danger thatgreen algae will grow, not to mention anexcessive increase in temperature in summer.It is therefore best to face the tanktowards the north or east. Do not hesitateto try out different positions with anempty tank before taking a decision withlasting consequences.• There are ahuge number oforiginal ways ofsetting off anaquarium.socket at an easy distance. A nearby tapwould also be an asset, but if this is notpossible make sure you have a hose forfilling and draining the tank. When theaquarium is set against a wall, it is advisableto leave a space of a few centimetersat the back to make room for cables andpipes. The height of the aquarium also hasto be planned with care, as it should be ateye level to be seen to advantage. Therefore,when it is placed in a main room, itsbase must be around 1 m from the floor,THE LIDThe lid, placed directly above the tank, is necessary forseveral reasons:- to avoid water spilling on the lighting hood;- to stop dust falling into the water;- to prevent any possible jumping fish escaping from the tank;- to reduce evaporation.The lid must be made of glass to allow light to enter the tank, andso it must be cleaned regularly. On a practical level, small pegsstuck to the top make it easier to handle, and some corners can becut away to make room for pipes and electrical cables. Also forpractical reasons, it is advisable to have several small lids which fittogether, especially in big tanks.The supportAs we have already seen, the weight of anaquarium is quite considerable. It is thereforevital to set up a sturdy and perfectlyhorizontal support (check the latter with aspirit level). Special furniture is availablein the aquarium trade, but you can just aswell build one yourself, the essential pointbeing that the weight is distributed onintermediary beams. The support can bethe same size as the tank or bigger, but itshould never be smaller, either in lengthor width. Put a sheet of water-resistantmarine plywood - 10-15 mm thick,according to the dimensions and weightof the aquarium - on the support, andthen cover this with a 15 mm thickpolystyrene sheet, which will compensatefor any irregularities in the support. If youare a do-it-yourself enthusiast and havepatience, you can set the aquarium,together with its support, into a piece ofwooden furniture, so that it can only beseen through its front pane.AVOID:- placing any decorative objects immediatelyabove the aquarium, as this makes using thelid impractical;- putting any electrical devices under theaquarium: this is dangerous, due to the possibilityof water spilling;- installing the aquarium near a radiator.220

MAKING AN AQUARIUMOF GLUED GLASSMaking an aquarium with glued glass isnot the exclusive domain of professionals;these days it is also an option for hobbyists.The crucial factor is the care taken inthe operation, along with a good organizationof the work plan and respect forthe sequence of the operation. It is advisableto practice first with a small rearingtank or hospital tank before taking theplunge and building a large aquarium.Hanging out in aquarium clubs can beuseful, as it will give you a chance to meetexperienced aquarists who can provideadvice or give you a hand when youcome to glue your first aquarium.ASSEMBLING YOUR TANKMaterials and tools• GlassThe fundamental material for your aquarium,the element which underpins its existence,is obviously glass. It can be cut tomeasure in glass merchants or do-it-yourselfstores. This operation must be performedcorrectly, as any slight mistake inthe cutting can have serious consequences,especially if the corners are notperfectly square.The calculation of the dimensions of thepanes must therefore be made with care,and do not forget to take into account thethickness of both the glass and the layerof glue (around 0.5 cm). The table belowgives you the dimensions of the glassrequired for two tanks of different volumes.You need a base, two small sides,the front, and the back. There are alsoprovisions for longitudinal reinforcements,which prevent the glass panesfrom curving due to the weight of waterand support the two-section lid. In largerMarine tankbuilt into awooden closet,made by anaquarist.Tank 3.7 mlong,reconstituting thebiotope of LakeMalawi.221

TECHNIQUESCUTTING THE GLASS FOR TWO DIFFERENT TANKSWe have chosen one tank of 96 liters and another of 200 liters (the gross volume in both cases)that can easily be built by two people.Do not forget to cut a piece off a corner of each section of the lid and have some pegs (around2x5 cm) ready to use as handles.Squeezing thesilicone glue ontoa sheet of glass. •222tanks, where the length isequal to or greater than 1meter, one or sometimesseverallateral reinforcementsare also required toconsolidate the unit.Offcuts of glass can be usedas pegs for lifting off the lids.After the cutting, rememberto ask for the edges to besanded down lightly, toavoid any unfortunate accidentsfrom splinters or sharpedges.• GlueA good glue is needed forsticking the glass wallstogether effectively: transparentsilicone glue for thispurpose is available. Whenexposed to the air it hardensto form a watertight join. The speed ofhardening depends on temperature, sospecial care must be taken in summer. Ata temperature of 19-20°C, the glue stayssoft for around 3 minutes, which allowstime for working. The hardening is sensitiveto the touch for 1 or 2 hours afterwards,and is complete in 48 hours.You are advised to be very careful whenhandling the glue. If you happen to spillor smear some, a dried run-off on asmooth surface can be easily scraped offwith a cutter. It is a lot more difficult ifclothing becomes impregnated with it.Above all, make sure not to rub your eyeswhen handling it and, in the event of anyaccident, consult a doctor immediately.This glue gives off a characteristic vinegarysmell which disappears after a littlewhile. It keeps well if the tube is closedwith its original cap and stored in a cool,dark, dry place.

ASSEMBLING YOUR TANK• Supplementary materialsYou will require the following materials forthe gluing process:- methylated spirits or acetone, for cleaningthe panes before gluing;- clean rags or absorbent paper;- cutter with a fine blade;- sticky tape;- small receptacle for water;- set square and tape measure.When you have assembled all the necessarymaterials, you are ready to go on tothe construction.Prepare a work surface large enough toallow you to spread out the panes andmove around freely. It is advisable to getsomebody to help you by holding thepanes.Sticking the various elements together(see panel overleaf).Installing the box filterThere isvery littlevolume must not be less than 1/10 of thetotal volume of the aquarium, if it is to becompletely effective. Inside the tank, youmust add the following parts, cut from 3 mmthick glass:- a glass panel separating the filter from therest of the aquarium, with a perforation toallow the water to flow through.Going back to the example of the two tankswhich served to illustrate the gluing of anaquarium, the dimensions of this panelwould be:• 28.7 x 38 cm for the 96 liter tank• 38.3 x 48 cm for the 200 liter tank.- four strips of glassintended to hold the filteringmaterial (3 cm wide and38 cm long for the 96 litertank; 48 cm long for the 200liter tank).These elements must bemounted in accordancewith the diagram below (ifthe filter is to be on the leftof the aquarium), with theglass strips in pairs facingeach other. They must notbe more than 8 cm apart. The distancebetween the perforated panel and the closestside is 8 cm for the 96liter tank and 10 cm for the200 liter one. Note that thebox filter is slightly lowerthan the main tank, toallow the water to circulate.• Panel dividingoff the box filter.Front view ofaquarium. •• To work efficiently, you must be ableto spread the panes out on a sufficientlylarge work surface.left for you to do, for the moment, apartfrom installing a box filter. The filtration systemcan be planned at the gluing stage oradded afterwards. It can be placed on theright or on the left and must be hidden byexterior trim, such as a wooden facing thatmatches the aquarium and its support. Its223

STICKING THE VARIOUS ELEMENTS TOGETHERThe sequence for the operation is as follows:1. Even if the glass panes were sanded when they were cut, run apiece of fine sand paper along the edges, then wipe them clean.2. Lay the panes flat, as in diagram B.3. Clean the parts to be glued with the acetone or methylated spirits.These areas must notcome in contact withyour hands, so thepanes must only behandled by their futuretop edge.Then allow to dry (itdries quickly).4. Apply the glue parallelto the edge of thepane (diagram C).5. Put one of the twolarge panels in place,then the two smallones (diagrams D andE). Note the positionof the hands on thetop edge of the panels.

6. Finish off by putting the second large panel in place (diagram F). If you are planning to use decoration made of syntheticmaterials, do not put the front pane in place straight-away, so that you can add it in greater comfort. Once you are through,finish off the gluing of the tank.7. Apply pressure to the areas which have been glued, to eliminate any air bubbles - this is extremely important. It is quitenormal for the glue to squeeze out on both the inside and outside.8. Use the sticky tape on the outer side to keep the four vertical panes upright (diagram G).9. Moisten a finger in the receptacle containingwater, then smooth down the glue on the inside ofthe aquarium. The result must be concave.10. Glue the reinforcements, wedge them, andsmooth down the glue (diagram H).11. Stick the pegs on the lids.12. Leave to dry for 48 hours. Carefully trim anyexcess glue on the outside and any smudges on theinside. Make sure you do not damage the parts youpreviously smoothed down.13. Place the aquarium on an absolutely flat surfaceand pour in water, to check whether it is watertight.The whole gluing process must be finished in 3 minutes,but there is no point in rushing: bad gluing canhave disastrous consequences for the stability andwatertightness of the tank.Of the possible problems that may emerge duringthis procedure, the three main ones are:- a pane may break when you are handling it;- you may make a mistake in the mounting, especiallywith the small sides, if their length and breadthare almost the same;- the pieces may not fit together properly.In the latter two cases, leave to dry, unstick, scrapeoff the glue with a cutter, clean, and then mount thetank again. If the aquarium leaks, indicate the sourcewith a felt pen or sticky tape, then empty the tankand leave it to dry. Clean the defective area andreapply the glue on the inside, making sure toextend beyond both edges of the source of the leak.

EQUIPMENT AND ACCESSORIESAn aquarium can only function properly with reliable equipment. It must be easy to putinto place and to use and it must offer every possible guarantee of safety, paying particularattention to the potentially dangerous combination of water and electricity. There issufficient variety in the aquarium trade to supply hobbyists with a reasonable choice, on thebasis of their particular needs and means. It is pointless (and expensive) to think big;besides, simplicity is often the byword for efficiency and success.LIGHTLight not only serves to provide visualpleasure and highlight the aquarium, it isalso essential to its equilibrium, as fish,like most living beings, need the alternationof day and night, which acts as a biologicalclock. The action of light alsomakes it possible for plants to performphotosynthesis and grow. Marine invertebratesthat play host to micro-algae (seepage 169) require strong lighting.An aquarium must therefore be equippedwith a light source which resembles as faras possible the one found in their naturalhabitat, as regards quantity and, mostimportant, chromatic quality.- the intensity of light supplied to theaquarium;- the duration of the lighting.You must be realistic as regards what youcan achieve: no artificial light is going to bethe same as sunlight. It is, however, possibleto get close, ideally with a combinationof different complementary light sources.Quality of the lightObviously, the best light would be that ofthe sun, which permits life on our planet.It is unfortunately impossible to take fulladvantage of it in an aquarium, for twomain reasons.Firstly, it cannot be quantitatively dosed.This means that too much light oftencauses the growth of unwanted algae, andso it is important not to directly expose atank to natural light, especially if it is facingsouth. On the other hand, if the directinfluence is deficient, the aquarium doesnot receive enough light to ensure that theplants grow satisfactorily.Secondly, sunlight does not adequatelyhighlight the aquarium and fish.It is therefore essential to resort to artificiallighting placed above the aquarium,usually in a hood specially designed forthis purpose. This lighting must satisfycertain conditions, as regards:- the type of bulb used and the quality ofthe light produced;226

Intensity of the lightThe total intensity provided by the lightingis an extremely important factor, asplants must be provided the amount oflight they need to grow in this artificialenvironment.It is inevitable, however, that some light islost, particularly if the beams have totravel long distances. The importance ofthe intensity of light (expressed, for thesake of simplicity, in watts) is often underestimated,and as a result many aquariumsare under-lit. It is unusual to find cases ofoverlighting.The tables on the following pages give theindications required for obtaining an optimumamount of light for your aquarium.As a general rule, the use of fluorescenttubes is generally recommended for waterup to a height of 0.5 m.EQUIPMENT AND ACCESSORIESLoss of lightThe further away the light source, thegreater the loss in:- the lighting hood;- the glass lid covering the aquarium;- the water.Part of the light is reflected by the surfaceof the water, another part is absorbed (thedeeper the aquarium, the greater theimportance of the absorbed light), and afinal part is diffused by suspended sediment.It is estimated that the bed onlyreceives 20-30% of the total light, whichcan be detrimental to the growth of smallplants.In order to reduce the loss of light, youmust:- recover as much as you can in the hoodthrough reflection;- keep the aquarium lid spotless;Light isrecognized asbeing importantfor plants, andalso for marineinvertebrates. Itmust besufficiently strongto reach thebottom of theaquarium.227

TECHNIQUESSome bluefluorescent tubescan compensatethe dominantyellow of HQIbulbs, resulting ina balancedlighting which isas pleasing to theinhabitants of theaquarium as it isto the eye of thebeholder. •- make sure that the water is clear;- maintain the depth of the water below0.5 m if you are using fluorescent tubes.Light sourcesA whole host of light sources, each withits own distinguishing features, is availableto aquarists.• Incandescent lampsThese are what we use from day to day inour homes, but they are absolutely out ofthe question in aquariums: the quality oflight is poor, and this type of bulb givesoff too much heat.• Fluorescent tubesIncorrectly known as neons, these tubescontain a gas that turns fluorescent underthe action of an electrical discharge. Theygive off little heat and are available in variouslengths and intensities. They last for3,000-4,000 hours, or around a year. Thequality of the illumination decreases overthe course of time, however, and this canbe clearly seen if an old tube is replacedby a new one. For this reason, neverchange all the tubes in a tank at the sametime, as plants may be traumatized by thisabrupt change in the intensity of the light.A used tube can be recognized by itsblack or dark ends. Fluorescent tubescome in various colors: firstly, the coldwhite or industrial white tubes, which areto be avoided, and the daylight tubes. Thelatter approximate sunlight the mostclosely and provide well-balanced lighting.Also available are colored tubes witha variety of dominants, including thetubes with a pink dominant used in horticulture,which are particularly effective forthe growth of plants, as they mainly emitblue and red rays, which are trapped byplants and used in the photosynthesis process.Some aquarists do not appreciatetheir somewhat unnatural color, whichtends to exaggerate the red and bluetones of fish. Sometimes tubes with a bluedominant are combined with white to createa light reminiscent of that found indeep waters. Such tubes are beneficial forcorals and other animals from the samegroup, and have therefore acquired thename of actinia tubes.Other colors are available, but they areless common. It is sometimes possible tofind tubes with a yellow dominant, whichare combined with blue tubes to achievea more balanced light.A fluorescent tube is not plugged directlyinto the mains: you must insert a transformer,the ballast, and a starter whichproduces the electrical dischargesrequired. If you buy a well equippedaquarium, or one with a lighting hood, thetubes will be provided. This does notalways mean that you can rest easy, as theintensity of the pre-installed tubes issometimes insufficient.• Halogen lampsThe tungsten filament of incandescentbulbs is here replaced by another metal,which prevents them from turning black.These lamps can be equipped with arheostat, but they are generally little usedby hobbyists.• Discharge lampsAn electrical discharge between two electrodesvaporizes a gas, such as mercury orsodium vapor - which emits an intenselight. These lamps have a slight yellowdominant, imperceptible to the humaneye, which is compensated by a blue fluorescenttube. They heat up and consumemore electricity than fluorescent tubes.Some, known as HQI daylight, are prizedby aquarists, but they are expensive andimpractical for normal tanks. They aremainly used in seawater aquariums over0.5 m in height, as they help to acclimatizeAnthozoans with Zooxanthellae (seepage 169).228

TECHNIQUESWatertight caps are available to protect the ends of the tubes and toavoid any electricital accidents. The ballast gives off heat, so it shouldnot be installed in the hood, althoughunfortunately this does occur in somecommercial equipment.Several different lengths of tube, withthe wattage adjusted proportionally,are available.• The hoodWhatever type of light source you choose,it requires a support: this is the hood. Fluorescenttubes must be included in ahood, out of reach of splashed water. It isoften protected by a pane of glass but. ifthis is not the case, the aquarium lidserves the same function. To avoid anyloss of light, any partition between thelighting and the water must maintain itsshape when exposed to heat, as well asbeing transparent and. above all, clean.Glass is therefore the ideal material. Lossof light in the hood can be substantial,sometimes up to 20-30%. There are afew tricks which can resolve this problem,the main principle being to reflectas much light as possible towards thewater. You can, therefore, line the insideof the hood with the smoothest possiblealuminum foil, coat it with white or metallicpaint, or make one or several semicircularmetallic reflectors to fit round thetubes. Some galleries on the market useone of the last two techniques. As theintensity of the light decreases when itgets further away from its source, it isimportant for the latter to be as close tothe water as possible. It should not be anycloser than 5-8 cm, for technical andsafety reasons, but even with these restrictionsthe illumination can be satisfactory.(This reduction in intensity has beentaken into account in the calculations forthe strength of the lighting and the numberof fluorescent tubes.)Duration of lightingHigh-quality lighting serves no purpose ifit is switched on only for a few hours aday; by contrast, there is no sense in providingillumination for 15 hours a day ifthe lighting is inappropriate. One will notcompensate the other under any circumstances.Once the lighting is suitable, bothqualitatively and quantitatively, you mustdecide for how long you are going toswitch it on.In tropical regions, the day lasts forapproximately 11 to 13 hours, and this iswhat wild plants and fish are accustomedto. The situation is different for plants andanimals raised in captivity, which can toleratedifferent lighting, but always withinthe bounds of reason. An aquarium canbe lit for 13 hours a day, but some hobbyistsexceed these limits, as they getused to turning the aquarium on whenthey get up and switching it off late atnight. In this way the lighting can be onSome, generally small, aquariums, include basicequipment. The lighting is therefore incorporated intoa hood which cannot get splashed by the water.. •230

EQUIPMENT AND ACCESSORIESA blue tube canbe added todaylight lamps torecreate thelighting in reefareas.WHICH TUBES FOR WHICH AQUARIUM?The following examples all assume a maximum water depth of 0.5 m and a minimum of three tubes.Type of tankClassic freshwater tank, averagenumber or few plantsType and combinationof tubes- A pink tube, combined with daylightlampsObservationsThis respects the balance of the colors,with the pink enhancing the growth ofplants. Low to medium intensity.Freshwater tank with abundantvegetationRegional East African tankMarine tank, without any plants orinvertebratesMarine tank with plants but withoutany invertebrates- At least 50% pink tubes, combinedwith daylight lampsA blue tube (for example, TLD 18 orBluemoon), combined with daylightlamps- Daylight lamps, possibly with a bluetube- A pink tube, combined with daylightlampsThis encourages the growth of plants,but at the expense of natural-lookinglight. High intensity.This attempts to recreate the naturallighting of these waters. Medium tohigh intensity.This attempts to recreate the naturallighting of clear reef waters. Low tomedium intensity.Balance between a natural-lookinglight and a light to enhance plantgrowth. Medium intensity.Marine tank with invertebrates(particularly Anthozoans)- An actinic blue tube (the TL03, forexample), combined with daylightlamps.For enhancing the maintenance andgrowth of invertebrates playing host toZooxanthellae. High intensity.231

TECHNIQUESGOOD LIGHTING REQUIRES GOOD INSTALLATIONThe positioning of fluorescent tubes in a hoodThe fluorescent tubes must be distributed with, optimally, a distance of 8-10 cm between them (diagram 1). In the fittedaquariums that are commercially available, the length of the tubes matches that of the aquarium, although it is noticeablethat the sides of the aquarium receive a little less light than the center or the front and back. Problems arise whenthe tubes are markedly shorter than the tank, which can occur incommercial aquariums with unusual dimensions, or in homemadeones. If the tubes are all centered, then there is a space on bothsides, which may disadvantage plants on the sides of the tank. Apartial solution to this problem is alternating the position of thetubes along the sides (diagram 2).Another option is the use of tubes of different lengths, makingsure that they are arranged to cover the whole surface of the tankand that their total intensity issufficient.How many fluorescent tubes are needed for good illumination?• The number of tubes required depends on their intensity and the size of the aquarium. Here are some indications forwater of a maximum depth of 0.5 m:Normally planted freshwater tank, marine tank with plantsDensely planted freshwater tank (Dutch aquarium, for example),regional East African tankSparsely planted freshwater tank, sea water without invertebratesor plantsSea water with Anthozoans (corals, anemones) and plants1 W/2 liters of water/ normal intensity1 W/liter of water/ high intensity1 W/3 liters of water/ fairly low intensity1 W/liter water/high intensityThese are the data, according to some standard dimensions, for a normally planted tank:Dimensions of tank(L x w x h in cm)Volume(in liters)Length of tube(in cm)Power(in W)Numberof tubes80 x 30 x 40100x40x50120x45x 50150x50x5096200270375609090120203030402344 or 5for stretches of 16 or 17 hours, which isfar too much. It does not especially harmthe fish, but it nevertheless changes thebalance of the aquarium, and is particularlyconducive to the development ofalgae. It is advisable to keep the lightingon for about 10 hours and switch it off ataround 10 or 11 o'clock at night. The useof programmed electrical clocks facilitatesthis operation, and particularly avoids anyabrupt and unnatural transition from darkto light, which can be harmful to somefish in the aquarium. In this way, theaquarium will receive the light of the new232

EQUIPMENT AND ACCESSORIESday first, followed byits own lighting. Oncethe artificial lightinghas been switched offat night, the tank willstill be able to takeadvantage of the ambientlighting.It is also possible tocreate a program thatswitches the fluorescenttubes on and off,one after the other,using several timers,thereby recreating, toa certain extent, sunriseand sunset.The ideal lighting programwould thereforeswitch on the room'sambient lighting in themorning, or allow thedawn light to exert its influence, then turnon one tube about 1 hour later, and finallyswitch on the other tubes a little later. Atnight, it would first turn off some of thetubes - with just one remaining lit - then,a short while later, the final tube. and.finally, the ambient lighting in the room.Last but not least: do not interrupt a daytimelight. Several hours of darkness,whether total or partial, unbalances thegrowth of plants and the behavior of fish.HEATINGAfter the vital matter of lighting, there followsa second issue, which is no lessimportant: heating. You must first establishyour requirements. The aquatic animalsand plants in tropical regions live inwarm water in which the temperaturehardly varies over the course of the year.Tropical aquariums must therefore beheated, with the temperature guaranteedat around 25-26°C, or even 27°C for seawater. These temperatures can be maintainedwith a watertight electrical heaterconnected to an adjustable thermostat thatswitches itself off once the desired temperaturehas been achieved. When the lattergoes down by 1°C or less, thethermostat reconnects the current and theheater starts to heat up again. Classic ther-mostats for aquariums allow the temperatureto be regulated with some precision,to around 0.5°C.More precise electronic thermostats arealso available. These react to variations ofthe order of 0.1°C, but unfortunately theyare more expensive.Heating equipmentOnce you have established your requirements,the next step is to choose theproblem of the heating equipment. Thereare independent elements available,attached to a thermostat, but they haveHEATING FOR BEGINNERSGood lightingmust both coverthe needs ofplants and satisfythe visual sense ofonlookers.A heater-thermostat is the most practical solution forbeginners. Make sure to choose a model in which the temperaturereadings are clearly visible. They often have a small light whichindicates when the element is heating up. The power depends onthe volume of water the aquarium will hold: calculate around1 W/liter, which means that a 100 liter tank requires a heaterthermostatof 100 W.A heater-thermostatmust always be totallysubmerged. •233

TECHNIQUES• Independentthermostat andheater: practical,if you want tomodulate thepower of theheating, butunwieldy asregards electricalcables.A heaterthermostatcomprises boththermostat andheater. It istherefore easier tohide than the twoseparate elements.•the disadvantage of multiplying thenumber of electrical connectionsand cables to be hidden.Another option is a heater-thermostat- combining both a thermostatand a heater - which is completelywatertight and submergible. Thissystem is becoming increasinglypopular as it is so easy to use.Finally, a less common type ofelement consists of a heatingcable sealed inside a flexibletube, which is placed in the sediment.Some aquarists, however,think that the diffusion of heat viathe bed damages the roots of plants.Furthermore, there is a danger that thecable may be partially unearthed by a burrowinganimal in the tank.The heating power levelThe temperature in an inhabitedroom - a lounge or bedroom -rarely falls below 17°C. If anaquarium is installed, the heatingmust be sufficiently powerful to gofrom this room temperature, whichwill be the same as that of theunheated tank, to one of around25-26°C.A power level of 1 W/liter is generallysufficient to ensure this increase intemperature. Therefore, 100 W will berequired for a 100 liter aquarium, andthis will also suffice for a 150 liter tank.In an uninhabited, and usuallyunheated, setting, such as a garage,cellar, or loft, a tank sometimesrequires up to 2 W/liter, but rarelymore than this.There is a sufficiently wide rangeof heating devices and powerlevels to cover all your needsfor volumes up to 500 liters(25, 50, 75, 100, 150, 200, and500 W). Beyond that, it ischeaper and easier toheat the entire premises(as in the case of clubsand public aquariums)than to heattanks individually.• The thermostat must be placed some distanceaway from the heater for an adequate control ofthe temperature.• A reliable thermometer is necessary formonitoring the temperature.Installing the heating equipment in theaquariumIt is important that the heat dischargedby the heater is spreadthroughout the aquarium, in orderfor the temperature to be relativelyuniform. Therefore, put the heaterthermostatin a turbulent spot, to helpspread the heat and prevent any areasbeing warmer than others. Anotheralternative is to distribute the heat bydividing the overall intensity - two heatsources of 100 W instead of a singleone of 200 W, for example - but thisentails more cables to hide, both insideand outside the aquarium. The thermometermust be kept away from theheat source, to avoid being directlyaffected by it.Possible problemsSometimes, the glass protecting a heatingapparatus may break, especially when234

EQUIPMENT AND ACCESSORIES• A diffuser placed under the heater-thermostatdistributes heat throughout the aquarium.you are handling it, and so it must bereplaced. However, before plunging yourhand into the aquarium, it is essential tounplug the heating system, as there is arisk, however minimal, of getting an electricshock - water, particularly salt water,is an excellent conductor of electricity.The heater's heating wire can break,meaning that the water is no longer beingheated and gradually cools. In this case,an internal black deposit appears in theheater, or on the heater component of theheater-thermostat.Another common problem is the blockingof the thermostat in the heating position:the metal strip "sticks" to its contact, theelement continues heating, and in a fewhours the temperature of the tank can soarabove 30°C. This can occur with well-usedthermostats, although the problem can beavoided with a second thermostat, insertedas a safety measure between the first andthe mains supply. If in doubt, consult aqualified electrician who has experience indealing with domestic aquariums or yourlocal supplier.AERATIONHere a question arises: should we speakof aeration or oxygenation? The two termslead to confusion, and it is sometimesthought that aerating the water meansintroducing oxygen. In fact, when a volumeof water is circulated, the agitation ofthe surface facilitates both the penetrationof atmospheric oxygen into the water andthe elimination of the carbon dioxide dissolvedin the water. It is not therefore thebubbles produced that directly oxygenatethe water, but the movement they create.Circulating also allows the heat given offby the heating apparatus to be diffusedand thereby distributed evenly over thewhole tank. The water expelled from thefiltercan alsohelp to stirthe water inthe tank.Obviously, if anaquarium is wellbalanced, there isno need to aerate it:this is often the case insmall, normally planted,and quite densely populatedtanks. However, gentle aerationdoes provide a degree of security.For large aquariums, in contrast, aerationis recommended, especially when theyhouse fish with high oxygen requirements,such as the large freshwater Cichlids.Strong aeration is similarly necessaryin marine tanks, in the form of vigorousstirring of the water, to recreate the conditionsof the natural setting.Aeration equipment• The pumpA small pump, connected to the mains,draws in the atmospheric air surroundingit and pushes it along a narrow pipe to adiffuser. This forms the bubbles that willbreak on the surface of the water. Thereare several models of pump, of varyingdegrees of output, according to the volumeof air required; the smallest are sufficientfor aquariums of a maximum volumeof 100-150 liters. Pumps make a certain• There areseveral types of airpumps; some havecontrols toregulate theirintensity.235

TECHNIQUESamount of noise, which mayseem a nuisance, as anaquarium is generally appreciatedfor the impression ofsilence and serenity that itcreates. The output ofsome pumps can beregulated, making itpossible to increase ordecrease the volumeof air produced.• A single pumpcan feed severaldiffusers, throughthe use of shunts,or also a filterplate.• The air distributionpipeThere are severaltypes of air distributionpipes, of varyingdegrees of rigidity, ofwhich the most commondiameters are 4-6mm. It is best tochoose one that is fairlystiff, as. if it happens toget jammed, it will notbe completely flattenedand will still allow a littleair to pass through.Always buy a piece oftube longer than youneed, to avoid anyunpleasant surprises.• The diffuserThere is a wide rangeof diffusers on the market: rectangular orcylindrical, in natural or artificial materials.The most practical ones are made ofREDUCING THE NOISE OF THE AIR PUMPSome pumps are noisier than others, and this can sometimes be irritatingwhen the aquarium is situated in a bedroom or other inhabitedroom. There are several ways of reducing this noise:- make a support for the pump, using a small wooden board on ablock of foam;- enclose the pump, in a cupboard, for example;- place the pump away from the tank, with a sufficiently long aerationpipe (an air pump often goes unnoticed in a kitchen, where itsnoise blends in with other household appliances);- if the output of the pump cannot be regulated, make a shunt witha faucet on the end, to allow a slight controlled escape of air (thissolution is effective only in some pumps).• There is such a huge range of aerationaccessories that no aquarist will have any problemfinding equipment suited to his or her individualrequirements.microporous or ceramic materials. Theseproduce very fine bubbles and can becleaned easily when they get clogged up.Do not forget that diffusers will becomeencrusted with calcium, salt, or algae afterthey have been in use for a while. Theyhave the disadvantage of floating, so theymust be held down, with a stone, forexample. Be aware that diffusers that producefine bubbles require stronger airpressure to maintain the flow.• Small accessoriesVarious small accessories complement themain items. Connectors, shaped in theform of a T, Y, or X, make it possible fora single pump to supply several diffusers.in the same tank or in different ones.HOW MANY DIFFUSERS IN ANAQUARIUM?This depends on the volume and type ofaquarium.- For a tank of 100-150 liters, normallyplanted, a single diffuser with a moderate outputis sufficient;- beyond that, in fresh water, calculate onediffuser for every 100-150 liters (one for every100 liters, if the tank is sparsely planted, ornot planted at all);- in sea water, use one diffuser for every75-100 liters, at top intensity.236

EQUIPMENT AND ACCESSORIESAERATION FOR BEGINNERSOne of the smaller pumps on themarket is sufficient, along with a few metersof pipe and a diffuser in microporous plastic.If the pump is placed below the water levelof the aquarium, it is vital to acquire a valveto prevent the water flowing back.Faucets regulate the flow when there areseveral channels. There is a variety ofmodels, in plastic or metal, single or insets for large installations.• Positioning the aeration equipmentIt is best to place the pump above waterlevel; this eliminates the possibility ofwater flowing back down the air pipewhen the current is switched off.A pump can sometimes be found belowwater level, especially in built-in aquariums,and so a small valve must beinserted to reduce the above risk.Perfectionists place the air pump outsidethe room containing their aquarium, toavoid any possible diffusion inside theaquarium of toxic products, such asaerosol sprays or cigarette smoke.Small filters are able partially to purify theair. These consist of active carbon thatabsorbs smells and fumes, which is placedin the air circuit after it leaves the pump.Many aquarists consider that bubbles in atank provide a somewhat unnaturalappearance, so they hide their diffusersand pipes in the decor, and the bubblesare only noticeable when they break thesurface of the water.For the reasons mentioned above, theideal position for a diffuser is close to aheating apparatus. However, make surethat no pipe comes into direct contactwith an element.Since a diffuser stirs the water, sometimesvigorously, it is possible that it also putsback into suspension various pieces ofdebris, such as excreta, uneaten food, andpieces of vegetation. If the suction of thefiltration system is nearby, this is not aserious problem; if this is not the case,there is a risk that this debris will spreadover the tank, with all the unappealingvisual results that may be expected. Toavoid this annoyance, do not put the diffuseron the bed, but to place it halfwayup the aquarium. It isadvisable to check that thelid fits properly at thepoint where the bubblesreach the surface, in orderto avoid any splashing ofwater onto the lightinghood. The faucets regulatingthe air must obviouslybe placed outside theaquarium. Often, in thecase of well plantedaquariums, no aerationequipment is used, as theplants themselves produceenough oxygen.It is not thebubbles from thediffusers thatoxygenate thewater, but themovement thatthey create.237

TECHNIQUESFILTRATIONWhy filter the water?Once an aquarium is put intooperation, the characteristics of thewater change fairly rapidly. Thesemodifications are a result of thebiological activity of living beings -plants, fish, and invertebrates - aswell as various chemical reactionsthat occur in the water and sediment.In this way the water graduallybecomes loaded withsuspended matter - animal excrement,vegetable debris, surplusfood, sometimes even dead bodies -and suspended solids produced by theactivity of the occupants.Of these, the most significant are thenitrogenous products released by animals'liquid excretion. These substances arevery toxic, and so their accumulation is acause for concern.The suspended matter remains in openwater, or ends up as sediment. In eithercase, it is visible. The suspended solids.External filter with several filtrationcompartments.on the other hand, are notvisible, and therein lies thedanger. It is however, possibleto ob-serve a slow modificationof the water color;in the long term, ittakes on a yellowishcolor. This alterationcan be detected veryearly on by immersing awhite object.Filtration therefore aims to trapthe suspended matter, in order toattain clear water that is more receptive tothe penetration of light and avoid any riskof intoxicating the residents of the tank.As we have already pointed out, filtrationalso contributes to good oxygenation. Youmust not, however, neglect to remove thebiggest scraps yourself.Principle of filtrationSeveral filters function by retaining suspendedmatter: this is mechanical filtration.The filtering media gradually becomeclogged and must be cleaned or changed.In order to transform nitrogenous substancesand encourage the nitrogen cycle(see page 19), oxygen and good bacteriaare required: this is biological or bacterialfiltration. The biological filter thereforecomprises a support that will be colonizedby bacteria, with circulation of water toprovide oxygen. The medium in mechanicalfiltration serves the same function as abiological filter once it has been colonizedby bacteria.The various filtration systems• The under-gravel filterThe water travels from top to bottomthrough the sand and is taken back inunder a platform that is slightly raisedfrom the bottom of the tank. The water isthen pushed out into the aquarium bymeans of an air-lift (see panel on page239) fed by an air pump. Here, it is thesand which acts as the filtering medium,via a double action: first mechanical, as itretains the particles that are in suspension,and secondly biological, as the nitro-238

THE UNDER-GRAVEL FILTERAdvantages- Inexpensive;-easy to install;- little or no maintenance;- easy to camouflage;- fed by an air pump (often thesame as the one used by adiffuser);- the water clears quicklyDisadvantages- It must be put in before the bed, when the aquarium is being built;- it can only, therefore, be removed by taking out all the decor, vegetation, and bed(which means reconstructing the aquarium);- the sand builds up rapidly, according to its density, and must be cleaned (taking usback to the point above);- draining the bed is not beneficial to most plants with roots;- the base of the air-lift may become blocked if it is narrow (under 1 cm); it can becleared by blowing down it, or by using a long thin rod;- when the filter is inactive for a while, there is a risk of deoxygenating the bed, whichcan cause the development of toxic products.THE AIR-LIFTThis ingenious system allows water to be raised to a certain height and also helps to stir, and therefore oxygenate it. As arough guide, an air-lift with a diameter of 3 cm, fed by an air pump, has a flow of several hundred liters per hour, with awater depth of 40 cm.The air-lift makes it possible to use an under-gravel filter or a drip filter, or send water from a box filter into the aquarium.In order to reduce the noise of the bubbles and enhance the circulation of the water, its top section can be bent to be flushwith the surface.This type of air-lift is available in the aquarium trade. It can also be made at home, using a pipeand a PVC bend (2-3 cm in diameter). It is attached to the tank with suction pads.

TECHNIQUES• Small internal filters with an electric motorThe motor makes it possible to draw upthe water through a thick grid that blocksthe passage of the larger pieces of debris.The water is then guided towards a filteringmedium, such as foam or Perlon,before being expelled into the aquarium.This system works well but is insufficientfor an aquarium with a volume of over 100liters, although there are models availablethat can be adjusted according to the volumeof water being treated and that willprove effective.• This undergravelfilter is usedwith a thicksediment thatserves as a filteringmediumgen cycle is created by the bacteria andthe oxygen supplied by the circulation ofthe water. The size of the grains of sand istherefore important (for more detail, seeChoosing the Bed, page 260), as it mustallow both the water to pass through andthe particles to be retained. This is whyyou should avoid sand that is too fineand, at the other extreme, sediment that istoo thick.The under-gravel filter used to beextremely popular, but these days it hasgiven way to other techniques. However,it can be used in small temporary tanks orin a community tank, but with a slow andcontinuous flow, as a complement toanother filtration system.• Small internal filters fed by airThese also work with an air pump, but asmall filtering medium, often made up offoam, replaces the sand. They are onlyeffective in small aquariums with a capacityof 50 liters or less.You can make this type of filter at home.Take a PVC receptacle that is easy to cut,ideally a bottle with a capacity of 1.5-2liters. The use of foam tends to make theapparatus float to the surface, so you mustinsert a ballast to weigh it down. Theupper part of the foam can be covered bycoarse, heavy material, such as gravel orsand, serving not only as ballast but alsoas a pre-filtration element (see boxbelow).A QUICK WAY TO MAKE A SMALLINTERNAL FILTER1. Diffuser2. PVC pipe, with incisions all down one side,which will be set into the block of foam3. Block of foam hollowed out in the center toallow room for the air-lift4. Gravel (pre-filtration and ballast)-> Direction of water1. Diffuser2. Air-lift3. Block of foam4. Water recovery chamber5. PVC bottle6. Gravel (pre-filtration and ballast)-> Direction of water240

EQUIPMENT AND ACCESSORIES• External filtersThe water siphoned into the aquariumpasses into a filtration bay containing sev-SMALL SUBMERGED FILTERS WITH AN ELECTRIC MOTORThe outflow of the motor is sometimes excessive for the volume ofthe filtering medium. The latter must be cleaned regularly as it getsblocked up - it can be inspected through the PVC of the filtrationcompartment.For a small tank, a small internal filter, usingeither an air-lift (left) or an electric motor (right) issufficient.eral filtering media and is sent back intothe tank by means of an electric pump.There is a variety of models available,depending on the power of the pump andthe volume of the filtration bay. It is evenpossible to find filters for garden ponds.These filters are highly efficient; theirmain disadvantage lies in the amount ofEXTERNAL FILTERS WITH AN ELECTRIC MOTORThese are suitable for large aquariums - some have a flow of 1 mVhour - and contain materials with various particle sizesin the filtration compartment. They must be placed at the bottom of the tank to avoid any possible draining.These filters are more expensive than those already described, but, though they are mechanicallyvery efficient, they are not effective in biological terms. Theuse of particles of different sizes prevents the apparatus fromgetting blocked up too quickly. It is easier to clean if youhave the foresight to install faucets on the pipes.1. Strainer to prevent small fish or bits of debris gettingsucked up and blocking the pipes2. Semi-rigid pipes3. Filtering media that get finer as the water advances4. Motor compartment5. Perforated rigid pipe which allows the water to beexpelled at or above surface level, to enhance theexchange of gases6. FaucetsDirection of the water241

TECHNIQUESPumps for box filters.space taken up by the equipment,with the pump and filtrationbay outside the aquarium,and the pipes for sucking in andexpelling the water inside.• Box filtersThese are sometimes built into someaquariums on the market, but they canalso be added afterwards. In the lattercase, they must be hidden by exterior fittings.The use of this type of filter is• A box filter integrated into an aquarium.becoming more widespread, as it is easyto put into operation and maintain. In alarge aquarium, however, its mechanism -the retention of particles - can proveinsufficient, and so a complementaryexternal filter must also be used.BOX FILTER1. Entrance for water through a hole in the glass, protected by a grid. A siphonwith a strainer on the end (la) can also be used. The grid or strainer preventsfish passing through, apart from the smallest fry, which can sometimes berecovered in the box (2). Both must be maintained regularly, as various bits ofdebris, particularly vegetal matter, build up there, slowing down or evenpreventing the circulation of the water.2. Box. This can contain a pre-filtration material, such as Perlon (page 248). Insea water, it is an ideal replacement for the protein skimmer (page 250).3. Filtration foam (page 248). This retains fine particles and is the medium forthe biological filtration. It is easier to maintain if it is divided into twoapproximately equal parts.4. Sump for keeping water before it is sent back into the aquarium by a pumpor air-lift. This part of the box filter can receive heating and aeration.There is a variation on this system: the double box filter.Double box filter242

EQUIPMENT AND ACCESSORIESBox filter incentral position,built intoartificial decorrecreating a cliffor rocky slope.•The box filter is normally placed on oneof the sides of the aquarium. Wherever itis put, it is vital that the volume of the filteris equal to at least 10% of the volumeof the aquarium. In the diagrams above,the aquarium is seen from above, with thefront at the bottom of the drawing; thefoam is represented by hatching. Thedecor can be artificial.• Wet-dry filtersHere, the filtering media are not totallysubmerged in the water, but are sprinkledby it.This means that they are in permanentcontact with the air, encouraging goodoxygenation of the water and effectivefunctioning of the nitrogen cycle. Thistechnique is particularly popular amongexperienced fishkeepers with large freshwateror marine tanks.There are two systems: the gutter filter,which has long been in use, and is easy toset up, and the more recent wet-dry filter,placed under the aquarium, whichrequires more space. In both of thesecases, coarse pre-filtration media aredesirable.- Gutter filter: the water is pushed upfrom the aquarium by an electric pump oran air-lift to a horizontal gutter equippedwith filtration material.The water then passesalong the gutter and fallsas 'rain' into the tank,thereby enhancing theoxygenation. Chicanes canincrease the time taken bythe water's journey and,therefore, its oxygenation.- Wet-dry filter under the aquarium: this isconsidered the ultimate filtration systemby some aquarists. The main problem insetting it up lies in the incorporation of anoutlet for excess water in a side wall orthe back of the tank. The water descendsinto another tank and drains through theTwo box filtersin the rear corners.Gutter filterequipped withthick filteringmedia (left) andfiner ones (right).VGUTTER FILTER243

EQUIPMENT AND ACCESSORIESPRINCIPLE OF WET-DRY FILTER PLACED UNDER THE AQUARIUMfiltering medium, before being pumpedback into the aquarium.Some manufacturers market small internalwet-dry filters, which are intended foraquariums of a maximum volume ofaround 200 liters.THE REAL POWER OF A PUMPHere is an example based on a 1,000liters/hour pump model, capable of reversingthe flow to a height of 1 m:In fact, a very slight curve should be visible,PUMPSPumps are used for box or wet-dry filters.In the case of marine aquariums, they aresometimes used merely to circulate thewater, or simply surrounded by a block offoam.• A pump's powerThere are several brands of pump andvarious levels of power. The power levelis calculated for the operation of a pumpthat does not raise the water level: thewater is pumped and sent back to thesame level.Manufacturers supply two figures forevery pump:- the maximum flow, which correspondsto a flow reversal height of 0;- the maximum water height to which thepump can take the water, correspondingto a flow close to 0.but the precision here is sufficient to see thatthe pump has a flow of no more than 600liters/hour for transporting water to a heightof 40 cm.The real power of apump actually dependson the height of thewater. •245

TECHNIQUESIn some rare cases, the directions for usewill include a graph that makes it possibleto calculate the real power correspondingto each height of flow reversal, but onmost occasions you will have to draw thisyourself.Uses, advantages, and disadvantages ofthe various filtering mediaThe filtering materials can be either natural- gravel, sand, clay, active carbon,peat, crushed oyster shells, rocks - or artificial- PVC, foam, Perlon, and variousplastic materials.Different materials correspond to specificfunctions.For a coarse filtration, use gravel, rocks,sand, clay, or large pieces of PVC.A fine filtration requires fine sand, foam,or Perlon; a biological filtration, sand,foam, cotton, or clay. Peat, active carbon,crushed oyster shells, or calcareous rocksare effective materials for exerting achemical action.With the exception of the last category, afiltering material must be chemically neutral,i.e. it must not modify the main characteristicsof the water (pH, hardness, ordensity).All the filtering media of variable volume(gravel, sand, earth, clay) are easier tohandle if they are placed in a fine-meshedpouch (made from a net curtain or tights,for example).• Gravel and thick sandThese are used as pre-filtration media totrap the largest pieces of debris, especiallyin the external filters. They are beingincreasingly replaced by artificial material,but fairly thick sand (grains of 2-3 mm)are still required in freshwater undergravelfilters.• Lava rocksThese rocks, broken into pieces of varioussizes, play a double role: mechanical, forsuspended matter, and biological.Theform and surface of the rocks encouragethe presence of bacteria, as well as goodwater circulation of water.• Oyster sheik and calcareous rocksThese play the same role, but also releaseWHICH FILTER FOR WHICH AQUARIUM?The type of filter depends on how the tank is being used, but also on the hobbyist's budget; youmust therefore look for the best quality/price ratio.The use of two complementary techniques makes it possible to obtain the maximum efficiency inbiological filtration. Also, this reduces the risk if one filter is affected by a technical or biologicalproblem.Type of aquariumVolumeFiltration systemObservationsRearing,quarantineUnder100 litersUnder-gravel filter, smallinternal filter, poweredby air or electricity.The under-gravel filter isnot the most practicalsolution.Fresh water100-200 litersBox filter orexternal filterIf the tank does not havean in-built box section,choose the external filter.• The prefiltrationmaterialis often coarse, inorder to trap thebulkiest particles.Fresh waterOver200 litersBox or external filterThe two systems can beused together.Sea waterOver 300 litersBox filter, external filter,wet-dry filterThese three techniquescan be used together.246

EQUIPMENT AND ACCESSORIES• Lava rocks provide a good bacterial support.moderate amounts of calcium carbonateinto the water going through them. Theyare therefore used to maintain a highdegree of hardness in some types oftanks, such as regional East African aquariums,for instance.They must be pounded and crushed, andthen rinsed carefully, in order to eliminatethe fine particles produced.• ClayClay, in the form of balls of a few mm to1 cm in diameter, provides a good bacterialsupport. It is rarely used on its own,but rather as a complement to anothermaterial, to ensure pre-filtration.• PeatPeat (see page 16) is placed in a filter toacidify the water passing through it; therefore,its main role is not filtration, althoughit can trap some particles. It is used infresh water to obtain the low pH requiredto keep and reproduce certain species (seeSouth American aquariums, page35, and also Cyprodontidae, orkillies, page 95). Beaware that peat turnswater an amber yellowcolor.It is, therefore, not atall advisable to applyPerlon retains fineparticles. It is an easymaterial to use. •Balls of clay can be used for pre-filtration.peat designed for horticultural use, as itcontains substances that can be dangerousin an aquarium. Suitable peat is commerciallyavailable, although you will have toproceed by trial and error and do sometests before finding the quantity needed tomaintain a specific pH.• Active carbonActive carbon is obtained by calcining(burning) vegetable matter under very preciseconditions. It is a very porous materialwith properties useful to fishkeepers. Itfixes organic coloring substances, whichmakes it possible to obtain really clearwater. It also fixes some medicines, especiallythose based on colorants. In thiscase, a filter is only used to eliminate amedicine, once the treatment has beencompleted. What is more, active carbontraps smells. Its main deficiency is that itloses these distinguishing properties quitequickly. It offers a good support for bacteria,but no more so than other more practicalfiltering media.To sum up, active carbon is a material withvery specific applications, to be used onlyin fresh water and not insea water, and it mustbe rinsed in warmwater before use.• PerlonThis artificial materialcomes in the form of intertwinedfilaments. Be careful: it247

• There is a veryw/de range offiltering materials;often the mostdesirable is theone offering thelargest surfacearea for trappingbacteria.• Polyester foamcomes in variousporosities, theideal onecorresponding to adensity of foam of20 kg/m 3 .must not be confusedwith glasswool, which ishighly unsuitablefor aquariums,as it canrelease tinyfragments intothe water. It isgenerally used inassociation withfoam as the first filteringmaterial, especiallyso in box andwet-dry filters.• FoamThis synthetic polyester foam has openpores, like that found in mattresses orcushions. This material is very fashionablein the aquarium trade these days and itseems to offer nothing but advantages: it islight, neutral, easy to handle and cut, aswell as being cheap. Furthermore, itprovides a highly effective bacterialsupport, and is also excellent formechanical filtration. The foamgenerally used has a densityof 20 kg/m-\ and its porosityis ideal both forretaining suspendedparticles and forallowing bacteriato develop. Generallyspeaking, theexperience of a greatmany aquarists and publicaquariums has shown that athickness of 8 cm, divided intotwo more or less equal parts foreasier upkeep, is usually sufficientfor filtration.lt is possible to find somecommercially available, orelse home-made, filters entirely composedof foam - small internal filters or externalfilters, both box and wet-dry - and theseare also completely satisfactory.• Various plastic-based materialsDifferent types of plastic material, such asPVC, can be used to make the filtration orpre-filtration elements: small pieces ofpipe around 1 cm in diameter, balls, cubeswith an openwork design, etc. The list isendless, and contains not only itemsfound in the aquarium trade but also recycleddomestic materials.• Combinations of filtering mediaWhen several filtering materials are foundin the same filter, the water must successivelypass through materials decreasingin grain size.The coarsest materials serve as a pre-filterfor large pieces of debris, while the othersretain the finer particles. All these filteringmedia enhance the development of bacterialcolonies that convert nitrogenousproducts, with pride of placebeing taken by foam and clayballs.Cleaning the filteringmediaThe filtering mediaprogressivelyaccumulate particles,at a rate dependingon granule size,the speed at which thewater flows through themand finally the amount of suspendedmatterit contains.When they aresaturated, they canMAKING A FOAM FILTER IN AN EMERGENCYThe sucking nozzle of an electric pump is extended with a pipe -PVC or semi-rigid plastic, such as a garden hose - with a series of slits downthe sides. This is inserted into a block of foam with the center already cut outwith a knife or blade. The water has to pass through the foam, before beingtaken in through the slit pipe and returned to the aquarium. This quick andeasy filter works well when improvisation is called for to keep an aquariumin operation.248

EQUIPMENT AND ACCESSORIES• A pump, a PVC pipe with slits down the sides,and a block of foam make up a filter that can bequickly put into operation.be cleaned with warm tap water, withoutany detergent or soap, until clear rinsingwater is hence obtained.Aquarists who have several tanks washseveral pieces of foam together in a washingmachine, though obviously withoutany washing powder. It is unfortunate thatcleaning eliminates the large majority, orindeed all, of the useful bacteria. The filterwill therefore be effective for particles butwill no longer be able to play any biologicalrole. To alleviate this problem, you canclean only half the filtering media eachtime: the bacteria living in the unwashedpart will be sufficient to purify the waterand will quickly recolonize the other half.If you are using two filters, you can, ofcourse, clean one at a time. If the aquariumhas to remain empty, in the meantime thefiltering media can be put into the filter ofanother aquarium, and in this way they willstill collect bacteria and can quickly be putback into service. It is vital not to interruptthe nitrogen cycle in a biological filter, asthis may give rise to toxic compounds.FILTRATION OF SEA WATERFiltration of sea water: special pointsIt is necessary to discuss separately certainissues specific to sea water. The ideal solutionwould be to use two filters: one witha moderate flow, mainly for the conversionof nitrogenous matter (a box or wet-dry filter),the other with a stronger flow, primarilyserving a mechanical function. Anunder-gravel filter can also be used to enhancethe circulation of water in the generallyfairly thick sediment, but it must notbe used on its own. One effective combinationconsists of a reverse-flow undergravelfilter coupled with an external filter(see box).The filtration flow must be 3-5 times thevolume of the tank per hour for fish, andup to 10 times the volume for invertebrates,especially Anthozoans. Once again,foam is the perfect material, providing it isno more than 6-8 cm thick. If thick materials,such as crushed oyster shells or PVCmaterials, are used, then the foam can bethicker. Never use peat or active carbon.Equipment specific to sea waterMarine fish are more sensitive to the qualityof the water than freshwater species.This calls for the use of equipment tocomplement the filtration system, in orderto obtain water of the highest quality.REVERSE-FLOW UNDER-GRAVEL FILTERThe water passes through the substrate from the bottom to the top,more for oxygenation than filtration. There are no particles to form sediment,as these are sent back in suspension into the water, which is filteredby an exterior system before being propelled under the sediment.1. Strainer2. Suction of water3. External filter with electric motor4. Return of water under the filter5. Under-gravel filter6. Passage of water from bottom to topThis type of filtration is sometimes used in large marine aquariumscontaining fish, thereby avoiding any possible problems resultingfrom a lack of oxygen in the bed.249

TECHNIQUESThe agitation ofthe water with aprotein skimmerprecipitates afoam made up ofsubstances to beeliminated. •The proteinskimmer, specificto sea water,eliminates certaindissolvedsubstances andhelps purify thewater. •• The protein skimmerThis system enables the aquarist to carryout partial chemical purification of thewater by eliminating certain dissolvedsubstances, such as proteins.The principle is simple: the water is agitatedin a confined space, leading to theprecipitation of a number of substances. Afrothy foam, often yellow-colored, is produced,and this is then eliminated via theoverflow.The protein skimmer is an independentelement that can be placed anywhere inthe tank. It can also complement the filtrationsystem, reducing the burden of abox filter when it is installed in its firstsection.Also very often employed as a preventivemeasure in tanks containing fish, the proteinskimmer is not used if the tank is notoverloaded, and if a biological filter isalready working effectively.The protein skimmer is recommended foran invertebrate tank, especially one withcorals and anemones, although it doeseliminate some substances that areabsorbed by invertebrates.Aquariums of up to 300 liters use a proteinskimmer fed by a finebubblediffuser, andtherefore supported by anair pump. Beyond thesevolumes, plan on installingtwo protein skimmers, orinvest in one fed by anelectric injection pump.• The purifying action of UVraysUltraviolet rays are luminous,but invisible to thehuman eye. Some of themare responsible for tanning(UV A and B), while others,with a shorter wavelength(UV C), have germicidalproperties and kill a large number of bacteriaand viruses.These UV rays are used for the bacteriologicalpurification of water, especially astheir action is selective, as they do notdestroy the "good" bacteria of the nitrogencycle.The field of action of these rays is limited- somewhere in the order of a few centimeters.The water must therefore passclose to the source of the rays, at a speedwhich allows it to receive sufficientamounts of their luminosity. In order forthe rays to exert their maximum effect, thewater must be clear, and therefore well filtered.UV sterilizers are commercially available.Again, the principle is simple: a lamp,usually a tube, sends out rays, and thewater is pumped around it. The power ofa UV system and the flow of the wateraround the lamp vary according to thevolume of water being treated. The lampis completely watertight, thanks to aquartz sheath that allows this type of rayto pass through. The blue-violet colorgiven off by the lamp only serves to showthat it is functioning. Do not look directlyat the source of the UV rays, as they aredangerous for the eyes — this is why thesterilizer usually has an opaque covering.The lifespan of a lamp operating for 24hours a day is around 5 or 6 months.However, the quality of the rays usuallydeteriorates after 4 months, and so theyshould be replaced three times a year.250

VITAL TOOLS FOR THE WELL-EQUIPPED AQUARISTThere are certain useful - indeed, indispensable- accessories that an aquaristalways needs at hand for everyday choresor the upkeep of the aquarium: a tool kit,in fact.ThermometerAbsolutely essential. An alcohol thermometer,colored blue or red, is sufficientlyprecise, although variations ofmore than 1°C can be recorded betweendifferent thermometers. Although mercurythermometers are more precise, they arealso a little more difficult to read. Whatevermodel is used, the thermometer isput into the water, away from the sourceof heating, to avoid being directly affectedby its warmth. It can be attached to aweight, wedged into rocks, or stuck witha suction pad.External thermometers with liquid crystalshave failed to convince most aquarists, astheir precision is not reliable.Various models ofthermometers areavailable, some inconjunction with adensity meter. Not allhave the same degreeof precision. •EQUIPMENT AND ACCESSORIESHydrometerWe have already discussed this (page 25),but it must be stressed that it is a vitalinstrument for monitoring the density ofsea water, i.e. the salt content.Equipment for analyzing waterSeveral brands of simple tests, used toanalyze water, are on the market. Theygenerally work on the basis of a change inthe color of the water, which must becompared with a scale printed on thepackaging. They are sold separately or incomplete kits, although it is possible torestock a basic product when it runs out,without having to buy the whole kit again.Four tests are more or less obligatory infresh water: general hardness (GH), carbonatehardness (CH), nitrites, and pH.The last three are equally indispensable insea water. There are other parameters thatcan also be monitored by small pieces ofanalysis equipment: nitrates, ammonia,oxygen, carbon dioxide, iron, and calcium(for marine invertebrate aquariums).Landing netsThese are obviously absolutely essentialfor catching moving animals. The size ofthe latter dictates the size of the net, alongwith the space available for handling it.Choose a small net for small fish or aquariumswith elaborate decor.However, it is not easy tocatch fish in a landing net.Aquarists will almost invariablytell you: as soon asyou want to catch a particularfish, it seems to see you coming!Once the net is put the water,pandemonium breaks loose,with foreseeable consequences:woundedanimals and thedecor, both vegetableand inert, turn topsy-turvy.One simple trick consists of puttingthe net into the tank at night, beforeswitching off the lights. The fishwill get used to its presence, andso it will be easier to catch thefollowing morning, when you switch thelights back on.The size of alanding netdepends not onlyon that of the fishbeing caught butalso on the spaceavailable in theaquarium forhandling it. •251

TECHNIQUESMagnets to cleanthe panes andvacuum cleanersconnected to an airpump arecommonplaceinstruments for tankmaintenance. • •• Garden pincersare very practicalin deeper tanks.Another possibility is the use oftwo nets, with one remaining stationaryto receive the fish beingpushed forward by the second.Landing nets must be disinfectedregularly with bleach (particularlyafter handling sick fish), andthen rinsed several times.Miscellaneous equipmentYou can also stock up with some otherpieces of equipment that often turn out tovery practical:- a long pipe for filling or drainingthe aquarium;- plastic food containers to holdwater;- pincers for planting, though manyaquarists prefer using their hands;- a scraper furnished with a razor blade ora small abrasive scouring pad, for cleaningthe algae on the glass panes;- a mini vacuum cleaner connected to theair pump, to siphon off waste products;- suction pads, faucets, nozzles and connectorsfor air and water pipes, availablefrom commercial aquarium stores;- an electronic timer for programming thelighting;- a notebook enabling you to keep trackof certain tasks: purchase dates for fish,results of the analysis of water, maintenanceschedule, etc.The latter is particularly recommended forbeginners, and also allows them to recordtheir personal observations on reproduction,sickness and the general behavior oftheir fish.252CABLES AND PIPES:LABELINGA fully equipped aquarium quickly accumulateselectric cables and pipes for air and waterand these have an irritating tendency to getmixed up, meaning that it is sometimes difficultto find the right socket, or the pipe thatneeds to be disconnected. To find them moreeasily, just stick a self-adhesive label at eachend of a cable or pipe and write on it thename of the corresponding element. In thecase of aeration, for example, a first label nearthe pump indicates which diffusers it is feeding,while a second just before the pointwhere the pipes enter the aquarium makes iteasier to locate the diffusers in question.• Small plastic tanks sometimes prove useful formaintenance operations, or for providing atemporary home for plants and fish when anaquarium is being repaired.

A BALANCED AQUARIUMAlthough an aquarium constitutes a self-contained environment, it nevertheless evolves: fishget bigger and reproduce, while plants grow. Similarly, the water undergoes changes thatmay not always be visible - the nitrate concentration increases but the mineral saltsdepleate- which is why it is important to analyze it regularly. As for the bed, this isenriched by numerous organic substances (animal excreta, surplus food) that will normallybe converted into mineral elements.MAINTENANCEThe equilibrium of an aquarium is fragileand can rapidly be disrupted if a few simplerules are contravened. The first ofthese rules requires a daily inspection ofthe tank and its occupants, at feedingtime, for example. In this way you candetect any sickness, worrying fish behavior,or an abnormal water color.The second rule is to maintain the aquarium.When undertaken on a regular basis,the upkeep of an aquarium is not timeconsuming,and only demands 1 or 2hours a week. Some operations need tobe performed every day, others less often.Water analysisBad water can cause problems unnoticeableto even the most discerning eye, so itis important to monitor its quality regularly.In both fresh and sea water, threemain parameters have to be monitored:the temperature, the pH, and the nitrites.Additionally, in sea water, the densitymust be checked, and, in fresh water, thehardness.Checking the equipmentYou must also keep a close watch on thesystems for lighting, heating, aeration, andfiltration.As regards the lighting, make sure that theelectrical contacts do not get rusty (especiallywith salt water). In the aeration system,the small lozenge which filters the airneeds to be changed twice a year. The diffuserseventually get blocked by algae orcalcium. It is best to change them, butthey can also be unblocked. Clean the filteringmedium regularly. Any malfunctionin the heating will quickly be reflected ina decrease or increase in the temperature:in this case, it is necessary to change theequipment.Cleaning the panesThe glass panes of the aquarium canaccumulate green or brown algae (page194), calcium, or biological deposits (bacteriaand non-pathogenic micro-organ-• Certainparameters of thewater, such as thepH, must bemonitored once ortwice a week.The moreregular themaintenance of anaquarium, the lesstime-consuming itbecomes.253

TECHNIQUESA Scrapers allowaccess right to thebottom of thepanes, to get ridof any unwantedalgae.isms). These deposits vary from oneaquarium to the next and do not in themselvesrepresent any danger to fish - thedamage sustained by an aquariumthrough a dirty front pane lies more onthe aesthetic plane. So the panes must bescraped with a razor blade or one of thesmall devices found in specialist stores.Domestic scouring pads can also be effective,but in the long term they scratch theglass of the aquarium. Do not forget toclean the glass lid, which gradually getscovered with algae and calcium (or salt, ina marine tank) on the inside and dust onthe outside, restricting the passage of thelight needed by plants.Looking after the bedAn assortment of debris piles up on thebed: fish excreta, bits of plants, surplusfood, and sometimes, in a quiet corner,even fish corpses. All this disrupts notonly the visual harmony but also the balanceof the tank as more oxygen isrequired to degrade this debris. These aretwo very good reasons for getting rid of itby siphoning (see box, page 255). Smallspecially designed vacuum cleaners areavailable in the aquarium trade, but youcan also use a flexible pipe draining outinto a plastic bowl, a sink, or a toilet.Changing the waterPartial water changes, at regular intervals,are one of the keys to success in fishkeeping.The combination of this operationwith siphoning eliminates bothassorted detritus and some of the nitrateswhich eventually accumulate.The clear water that is introduced suppliessome mineral elements and provides astimulus for the aquarium: the growth offish, the triggering of egg-laying, and thegrowth of plants.After 2 months or so you will see a strikingcontrast with aquariums in which thewater has not been renewed. A change of5-10% of the volume per week is thereforerecommended. This obviouslydemands a stock of water with identicalcharacteristics to that of the aquarium(especially pH, hardness, and salinity).PARAMETERS TO BE MONITOREDParametersFrequency of monitoringObservationsTemperatureNitritesPHDensityTotal hardnessCarbon dioxideEvery dayOnce or twice a weekOnce or twice a weekOnce a weekOnce a weekOnce a fortnight (sometimes less)It must not vary by more than 1°C.Ideally, they should be totally absent.The photosynthesis process and the respirationof animals cause variations from day today.Only in sea water. It must not vary by morethan one or two units.In fresh water. Slight variations are notabnormal.Mainly in quite densely planted aquariums.CalciumOnce a weekIn sea water, in aquariums containing corals.In the event of any serious problem, you must immediately change one third of the water, then 10% per day for thefollowing 5 days. The substitute water must always present the normal characteristics of the water to be replaced(particularly pH, hardness, and density).254

A BALANCED AQUARIUMA TRICK FOR SIPHONING OFF WASTEPeople who live with aquarists dread siphoning time, as it often leads to floods! The pipes can be too flexible, with a tendencyto slip out of the aquarium or the container for the siphoned water.The trick is to get hold of a washing machine draining pipe or a snorkel, and slide the siphoning pipe inside it, making itpossible to bend it over the side of the container or tank. A stiff bent pipe can also be used to siphon in the less accessibleparts of an aquarium (grottoes, for example).The ideal solution is daily renewal of asmall amount, with the help of a drip (seepage 256). This technique is becomingmore common among experienced aquarists.It requires a special installation, andabove all an overflow for the aquarium -equipment which is not readily availablein every case.However, many fishkeepers find this systemthe ideal solution:- the maintenance is reduced, as thewater changes are less frequent;- there are no abrupt variations in theenvironment;- various substances, such as nitrates, areregularly eliminated and therefore do notaccumulate;- it entails a regular, though limited, supplyof the various substances contained inthe water (mineral salts, trace elements);- the pH is stabilized;- this method seems to restrict the growthof certain somewhat unsightly algae.A word of wisdom: the water siphoned offa freshwater aquarium is excellent forwatering house plants as it contains dissolvedorganic matter!Evaporation and the water levelThe water in an aquarium evaporates.This has no ecological consequences, butit does mean that the surface of the watercomes into view at the top of the panes,which is hardly attractive. This must thereforebe adjusted on a regular basis, usuallyat the same time as you make a partialwater change.After a while a regular increase in thehardness of fresh water (or the salinity ofsea water) is noticeable: the water thatevaporates from the surface is fresh watercontaining no salts, even in sea water, andso there is a progressive concentration ofsalt or other mineral substances in theaquarium.To avoid this problem, replace the evaporatedwater with very soft or demineralizedwater in order to readjust thehardness or density. This can be donewhen you change the water, by slightlydiluting the new water with fresh water.Readjustment of the water level is not necessaryif you are using a drip that functionsautomatically.When stemmedplants grow toobig, you canconsider takingcuttings.255

TECHNIQUESA SIMPLE DRIP TECHNIQUETwo points must be taken into account: the arrival of the new water and the overflow of the aquarium water.Do-it-yourself experts may consider making a connection with the plumbing pipes in the home, but there is a more simplesolution. Take a PVC container, such as a jerry can with a faucet, for use above the water level of the tank. For aestheticreasons, this is hidden in a cupboard or other piece of furniture. A flexible PVC pipe can be used to connect thefaucet with the aquarium.Water from the aquarium can flow intoanother container, larger than the first, toavoid any risks of overflowing (diagram 1).There remains the problem of the aquarium overflow. You can get a glassstore to make a hole in a side or rear pane when you are mounting or buyingthe tank. Insert a PVC plug with connections for the evacuation pipe; donot forget to also provide an escape for the water (diagram 2).There is another solution: use a siphon that functions continuously(diagram 3). The water level can be regulated by raising or loweringloop A, and a small diameter (1 cm) ensures the continuity of theoperation.This device can easily be attached to the inside and outside of theaquarium with suction pads. It is best not to put a diffuser near theentry of the siphon, as there is a danger that bubbles may interferewith its functioning. Always put a strainer on the end to avoid anysmall fish or large pieces of debris from getting sucked up and causinga blockage. The system is set in motion by sucking on the pipe.You will have to adjust the drip by trial and error, after calculatingthe volume that needs to be renewed (around 1 % of the volume ofthe aquarium per day).256

Maintaining the vegetationWhen you are siphoning on the bed, youmust remove any dead leaves that mayhave fallen. Likewise, cut off, with a razorblade or scissors, any leaves that are startingto rot.When the plants need a new lease of life,you can take cuttings or use anothermeans of vegetative multiplication.Liquid or solid fertilizer should be addedregularly; the instructions on the pack willtell you how often and at what rate eachproduct needs to be added.WHEN THE AQUARIST ISAWAYWhat do you do if you are away for morethan a day? What will happen to theaquarium? This depends on the length ofthe absence, and certain precautions mustbe taken, especially for vacations.Short absences do not represent a problem.Freshwater fish can go without foodfor two weeks, or even three in the mostrobust species, but marine fish, on theother hand, cannot endure fasting formore than a week. This only applies toadults, as the fry must always be fed on aregular basis.A long absenceThere are two options for a long absence:- the first consists of using an automaticfood distributor controlled by a timer,which can only be used with dry food;- the second is finding a friend kindenough to feed your fish for you - preferablyanother aquarist who will monitorthe feeding and the aquarium just as youwould. If your friend is not a hobbyist,then you must prepare daily doses of dryfood and leave him or her some instructions,in order to avoid anyoverfeeding. (However,this friend will not beobliged to drop by yourhome every day, one ortwo visits a week beingThe use of batteries makessome food distributors automaticand very practical.generally sufficient). Plants can go withoutlighting for one week, but after anylonger period they turn yellow and graduallywither. It is therefore advisable toinstall an automatic timer that will switchthe aquarium lighting on and off at specifictimes. This means that there is noneed to let the sunlight into your homeand so you can close your shutters. This isparticularly relevant in summer, as itavoids any excessiveincrease in the temperature,which will haverepercussions on theaquarium.Vacations• Before leaving:- check the pH, nitrites, temperature,hardness, or density;- check the equipment;- clean the filtering media and panes; dothe siphoning;- increase the frequency (but not thequantity) of water changes;- put the vegetation in order by trimmingthe plants and taking cuttings. You canalso add plants with fine leaves for herbivorousfish, if they are not going toreceive any other food;- slightly overfeed the fish for a few daysbefore your departure;- switch on the automatic lighting systemand, if you are using it, an automatic fooddistributor;- make a final check thenight or morning beforeyou leave.• When you get back:- switch off the automaticdevices and generallyput the tank in order(siphoning, panes, filtering media, vegetation);- change 5-10% of the water every day fora few days;- give the fish smaller portions of foodthan normal - if possible including liveprey or fresh food - and graduallyincrease these amounts until they reachthe usual level.A BALANCED AQUARIUM• The lighting canbe controlledautomatically witha small electrictimer.• Automatic fooddistributor with amains connection.257

THE WATER COLOR, EVIDENCE OF A GOOD BALANCEThe water in an aquarium should usually be clear and transparent. Coloring can appear gradually (yellowish or amber)or more quickly (turbid, milky, or green water).Turbid, milky.Water colorYellowish or amber (anamber color is normalwhen the water is acidifiedwith peat, or when thereare roots in the aquarium).Causes, problemsDevelopment of bacteriadue to malfunctioning filteror overfeeding.Accumulation of organicmaterials due tooverpopulation,overfeeding, or amalfunctioning orundersized filter.What to do- Change 30% of the water immediately, then repeat theoperation 48 hours later.- Check the filter and the filtering media.- Put a UV lamp into operation (in a marine aquarium).- Reduce the food for a few days.- Change 30% of the water immediately, then repeat theoperation 48 hours later.- Check the filter, increase the strength of the filtration.- Reduce the numbers of fish, feed reasonably.- Put in an aerator or increase its strength if there alreadyis one (in a marine aquarium).- Increase the oxygenation.Green water (a rarephenomenon).Proliferation of microscopicplanktonic algae (maybedue to an excessive"richness" in theaquarium).- Change 10-20% of the volume of the tank every day.- Do not illuminate the aquarium for a few days.- Increase the filtration rate, then thoroughly clean thefiltering media a few days later.- Prevent any sunlight from reaching the tank.

POTENTIAL PROBLEMS - ANDHOW TO SOLVE THEMNo matter how many precautions aretaken, nobody is completely invulnerableto problems with the equipment or theequilibrium in an aquarium.An electric power cut, for example, has nodramatic consequences over a shortperiod, but it is worrying if it lasts a wholeday (rarely the case, it is true). The aquariumcools, but the heat loss can bereduced by wrapping the tank in a blanket(also the solution to any malfunctioningof the heating system).Generally speaking, in the event of apower cut there is a danger that the waterstagnating in the filter will acquire substancesthat are toxic to the fish. It istherefore very important to empty itbefore turning the power back on andputting the filter back into operation.An abnormal increase in the temperaturecan occur if the thermostat gets stuck inthe heating position. The only real solutionis to unplug it and adjust it, and allowthe temperature to slowly drop to its initiallevel.The temperature can also go up in summer,depending on the room where theaquarium is housed. The thermostat obviouslyturns the heating off, but the temperaturecan still sometimes exceed25-26°C. There is no need to panic up tothe 27-28°C level, but you must makeprovisions for cooling the room by darkeningit, to avoid the penetration of sunlight.Note that substituting part of thewater with domestic water or putting icecubes in the aquarium have little effect.The water color is a good indicator of theequilibrium of the aquarium: if it is clearand transparent, there are apparently noproblems, but any coloring may be thesign of imbalance.A drop in the pH is often the result of anexcess of carbon dioxide dissolved in thewater. This can be solved by increasingthe rate of aeration.Finally, you must be prepared for a rareaccident, such as a leak, or a crackedpane. If this happens, you must actquickly, transferring the plants and fish toanother tank, with their original water.The aquarium must then becompletely emptied anddried, and you must locateand block the leak or changethe cracked pane, using thegluing techniques describedon pages 224-225.Remounting an aquariumA well-balanced aquariumcan be self-sufficient for up toone year, or even more, if it ismaintained on a regular basis.If this is not the case, remounting must beconsidered. This can also be done whenyou want to change the decor, move theaquarium, or even move home. Plants andfish must be stored in another tank, withtheir original water. Then take out all thenon-living elements, and clean and storethem until they are used again.Now comes the turn of the actual aquarium.Start to put it back into operation byreintroducing fresh water of the appropriatekind.If the aquarium is to be remounted in asingle day, it is advisable not to wash allthe sand that serves as a bed, as it containsthe good bacteria needed to undertakethe nitrogen cycle. A rough rinse willget rid of the bigger pieces of debris, withonly the top layer being cleaned severaltimes, until the water is clear, for a goodvisual effect.A BALANCED AQUARIUMA younghobbyist andaquarium dubmemberremounting severaltanks.GOLDEN RULES FOR A GOOD BALANCEHere are some important rules to follow as regards awell balanced aquarium:1. Think big: the greater the volume of the tank, the easier it willbe to maintain its balance, especially with sea water.2. Make provisions for good filtration and aeration.3. Consider planting the aquarium, even with sea water: manybeginners do not put enough plants in their tanks.4. Start with robust fish, easy to raise and recommended fornovices: these are not unattractive, and are often found to be theleast expensive.5. Do not overpopulate.6. Do not overfeed.7. Regularly monitor the temperature, the pH, the nitrites, thehardness (in fresh water) or the density (in sea water).8. Regularly siphon and change part of the water.259

CHOOSING THE BEDThe bed does not merely serve an aesthetic function - it must also contribute to the overallbalance of the aquarium. It is a living environment in which various physical, chemical,and biological mechanisms unfold in accordance with its composition and granule size. Itis therefore important to make the right choice of material at the aquarium's planning stage,in order to satisfy all these requirements.THE ROLE OE THE BEDThe main role of a good bed is mechanical:it supports the decor, made up ofrocks and other elements. This is why,when an aquarium is being mounted, thebed is put in after the decor.The bed also has a biological role that isno less important: it contains bacteria thatcontribute to the nitrogen cycle, and istherefore involved in the elimination ofnitrogenous compounds. This is particularlyvaluable if you are using an undergravelfilter.Of course, the most obvious role for thebed is to enable plants to take root, particularlyin fresh water.For all these reasons, a bed must have thefollowing characteristics:- medium granule size;- look both visually pleasing and natural;- not too dense, although sufficiently sofor plants to be well rooted.Do not forget that a bed is heavy - 1.4-2kg per liter volume - and so you mustplan for an adequate support for theaquarium (around 30 kg of sediment for aWHAT DEPTH OF SAND?Enough to enable the plants to take root, but not toodeep, to avoid spoiling the appearance: 5-8 cm is atheoretical standard to be adapted to each particular case.Only a hospital aquarium has no bed at all, for obvious hygienicreasons.The table below gives the approximate weight of sediment fora surface of 1 m 2 . Generally speaking, coarse sands neverweigh less than 70 kg/m 2 .• The depth of the sediment is an importantfactor in the establishment of plant roots.260

CHOOSING THE BEDIn this marinetank, seen fromabove, the bedserves as a wedgefor the decorativeelements.There are varioustypes of sand,with differentsized particles andcolors.100 liter tank, with the whole aquariumamounting to some 150 kg).DIFFERENT TYPES OF BEDNatural beds in freshwater aquariums• Coarse sand and fine gravelThese are the best sediments for aquariums.Quartz sand comes from crushedsiliceous rocks (granite). Its grains, 1-3mm long, have sharp splinters that can irritateburrowing fish, but it enables thewater to circulate well. Its color variesaccording to its iron oxide content. Quartzsand is considered a sediment low in nutrients,and it is better suited to filtration.Loire sand, as its name suggests, originallycame from the bed of the river Loire inFrance. These days, identical sand is takenfrom other rivers or pits. The grains aremore eroded, and therefore finer (0.5-1mm), than those of quartz sand. When ithas been taken from rivers, it containsresidues of nutritive material that can beabsorbed by plants.• Fine sandThis pale-colored sand appeals to manyhobbyists, but it has the disadvantage ofnot allowing the water to circulate freely.Moreover, unsightly deposits of plantdebris, excreta, and leftover food show upvery clearly, and, finally, the finest grainsDark sediment canbe used to set offpale fish.DIFFERENT TYPES OF SEDIMENTSedimentDark or black sedimentUseOften volcanic, it is sometimes used to set off pale fish, whilethe traditional sands are better suited to dark or brightly coloredfish.GravelPozzolana and othervolcanic rocksIn sparsely planted aquariums, or those containing plants withsturdy roots, for big fish (Cichlids, for example, although it isnot the most appropriate substrate).These produce a very thick sediment when crushed, providingexcellent water circulation. Some have a distinctive reddishbrowncolor. More widely used for their visual effect than for anatural look.PeatSupport for the eggs of killies. (Egg-laying Cyprinodontidae,see page 95). See also page 16.261

TECHNIQUES• Some fish (here,Sturisomarostratum, fromSouth America)use fine sand tohide themselves,either wholly orpartially.of sand may finish up suspended in thewater. However, bottom-dwelling fishendowed with barbels seem to appreciatethis type of sand. Other specific factorsrelated to its use can be seen in the tableon page 261.• Collecting sediment from a natural settingSome aquarists may be tempted to collectsediment themselves from a natural setting,although in theory this is forbidden. Aclean and well-oxygenated watercoursemust be chosen. The granule size graduallydecreases as the water flows downstream.Sediment can often be found where it hascollected in the inner part of a bend in awatercourse.Enriching natural bedsLike a gardener, the aquarist can enrichthese natural soils, as the most commonsands, like quartz and Loire sand, aresomewhat deficient in mineral elements,and so there is a danger of plants beingaffected by this when the aquarium is putinto operation. Remember that it is possibleto add both solid and liquid fertilizersto compensate for this deficiency. Once agood equilibrium has been achieved, thebed will gradually get richer and will startto be really beneficial to plants after about4-6 months of operation.Hobbyists who want their plants to growmore quickly can introduce an enrichedsubstrate at the outset. This is available,already prepared, in the aquarium trade,but you can also make your own enrichedbed on the basis of a recipe used andadvocated by countless fishkeepers andspecialist magazines (see box below).However, beginners are advised to startwith a normal or commercially enrichedbed, before moving on to create specificindividual substrates.THE BED AND OXYGENAs a general rule, a bed must beconsidered as facilitating the movement ofwater. The water supplies oxygen to themicrofauna living in it, enhancing theprogress of the oxygen cycle. If the sandused is too fine, it becomes too compact toallow the water to circulate freely.This may give rise to black patches, a sign ofoxygen deficiency and the presence of toxicsubstances.MAKING AN ENRICHED BEDThe classic recipe is:- 10% clay: this enhances the use of mineral salts by the plants;- 40% heath-mold without manure: beware of false heath-molds and various types of compost;- 50% unprocessed Loire sand: if this is not washed, it contains mineral elements.Mix the ingredients and put a 1 cm layer of quartz sand on the bottom, followed by 2-3 cm of the mixture and packdown thoroughly. Cover this with a few centimeters of quartz sand.Obviously, you will not be able to dig around in this kind of substrate, so do not forget to put the decor in place beforehand.Do not use an under-gravel filter with this substrate. It might be argued that it is not oxygenated, as we have previouslyrecommended, and this is true. However, it does produce other reactions, and accidents with it are very uncommon.Some aquarists have reported that this type of bed can remain effective for more than one year, sometimes more thantwo. Even if you are reluctant to apply this method directly in an aquarium, it can nevertheless be used in small aquaticjardinieres containing plants. This certainly has practical advantages - they are easy to move - but you will have to camouflagethe bed.262

CHOOSING THE BEDNatural beds in marine aquariumsIn a marine tank the bed plays a differentrole, as the sparse vegetation found in thistype of aquarium does not take root in thebed, and so the sediment does not needto be very dense and can be made up ofcoarser granules.Two materials are used mainly, but theyare often confused and grouped togetherunder the term "coralline sand".• MaerlThis is a coarse sediment, taken from certainsea beds and consisting of calcareousalgae and the remains of mollusk shellsand Anthozoan skeletons. It is very rich incalcium and reduces variations in pH.• Crushed coralThe thickness of this sediment can vary,depending on the extent of the crushing.It consists entirely of pieces of the skeletonsof corals and other similar animals.The fragments have been sufficientlyeroded so that any injury to creatures thatwalk on the bed or burrow into it isunlikely.It contains practically no calcium, but itdoes control any variations in the tank'swater pH.These two beds for marine tanks areavailable in the aquarium trade.• Live sandThis is taken from the sea and sold moistby aquatic retailers. It contains a largenumber of micro-organisms, such as thebacteria in the nitrogen cycle. It is therefore,in theory, ready for action as soon asthe aquarium is put into operation, whichis not the case with other sediments.However, the results differ greatly fromone tank to another, and many hobbyistsare unconvinced about the beneficialeffects of this sand.There is a temptation to collect sand fromthe seashore, as it contains bacteria, butseveral precautions must be taken if youchoose to do this.Find an area free of pollution, with plentyof movement in the sea, and collect somecoarse sediment. If this only comprisessand it will be deficient in calcium, but itcan be topped off with crushed oystershells. It is best to look for a shell sediment,mainly consisting of pieces ofbivalve mollusk shells. Rinse the sedimentthoroughly before introducing it into theaquarium, in order to eliminate the finestgrains.N.B.: dune sand is absolutely unsuited tomarine tanks.• Crushed oyster shellsThese can be mixed with the abovecoarse sands to increase the levels of calcium.Wash them thoroughly, to get rid ofany fine particles.It must be pointed out that the last twotypes of sediments are not to be found inthe regions inhabited by tropical fish.They cannot therefore be considered asreally natural, but they can be used as asubstitute for coralline sands as they aremore accessible - and cheaper.• In principle, it is illegal to take large quantities ofsand from a beach, but no aquarist has beenknown to encounter problems for extracting smallamounts.Two types ofsediment are mostcommon in marinetanks: maerl(above) anderoded andcrushed coral,which is coarser,below.

DECOR AND BACKGROUNDThe decor is extremely important, as it exerts a decisive influence on the visual impact of theaquarium - and the pleasure derived from a beautiful scene is surely one of the mainsatisfactions of fishkeeping. However, do not get carried away, and make sure that theoverall effect still has a natural look.In sea water, thedecor cansometimes serve asa support for theinvertebrates thatlive attached to it.•264Decor based onplant material:peat-bog rootsand willowbranches. •DECOR: A VITAL ELEMENT INAN AQUARIUMThe role of decorDecor is necessary for some animals andplants to feel at home. Shy fish look forpermanent hideaways in it, while othersfind the refuge they need to reproduce,laying their eggs on verticalor horizontal rocks.Even if the residents donot make use of the shelterprovided, the decorgives them physical referencepoints, whichallow some species tomark out their territory.These observations areequally applicable toinvertebrates, some ofwhich - Anthozoans, forexample - live attachedto elements in the decor.When an anemone is firstintroduced into an aquarium, it is notunusual to see it move around beforeestablishing itself in the spot best suited toit. The decor also provides a support forcertain types of vegetation: ferns andmoss in fresh water, Caulerpae, and otheralgae in sea water.Finally, the decor allows you to hideequipment, mask the glass panes, and cutoff the rear corners, thereby providing abackdrop and bringing harmony to theaquarium overall.Main characteristics of decorApart from the search for a visual effectand a natural look, some rules must berespected when you are designing yourdecor. It must be functional, accessible,and easy to maintain. The material used,except in rare cases, must be neutral, i.e.it must not modify the characteristics ofthe water. It must also be solid enough toresist fish like Cichlids, which like to rearrangethe furniture.Of course, the decor increases the weightof the aquarium. Calculate for an averageof 60 kg per square meter, although it willbe a great deal less if you are using artificialmaterials, in freshwater tanks that aredensely planted, Dutch aquarium style,and in marine tanks.Once again, do not forgetthat the decor mustbe put in place beforethe bed is laid.DECOR IN FRESH-WATER TANKSRocksRocks suitable for use asdecorative elements inan aquarium can befound in natural settingsor in specialist stores(see table page 265).Make sure they have no excessively sharpsplinters: sand them down to ensure thatthe fish do not get injured when in contactwith them.How can you recognize a calcareous rock?By repeating a triedand tested experimentthat some ofus performed inschool: pour a fewdrops of vinegar oracid onto the rock.If a slight effervescencedoes occur,which is caused bythe release of carbondioxide, thismeans that the rockcontains calcium.The same methodcan also be used totest sand.

DECOR AND BACKGROUNDSOME ROCKS FOR FRESHWATER AQUARIUMSCalcareousShaleTypesObservations- only to be used to increase or maintain the hardness of the water(East African or brackish water aquariums).- various colors: gray, greenish, or reddish;- it can be split into thin, light leaves, practical for hiding accessories.SlateLavaBasaltShingle- black sets off plants and fish well;- beware of slate with golden flecks, as it contains metals.- light rocks broken off or thrown out in eruptions;- various co ors: reddish, brown, black.- heavy lava with sharp splinters.- heavy but with smooth edges;- useful for building a small structure with shelters;- typical of flowing waters.Petrified wood- this is not a rock, but silica which has gradually replaced the livingparts of the wood; the fibrous structure is still visible;- striking decorative effect, pale color.Wooden materialsThe natural environments of our fish oftencontain more vegetation than rocks: roots,branches that have fallen into the water,bark, and plants that become submergedin the rainy season.When used alone or with a rock, woodcreates a beautiful decorative effect, especiallyif it alsoplays host to mossor ferns.It is therefore logicalto use wood inan aquarium, but itmust be treatedfirst. Woodenmaterials have twomajor disadvantages.Firstly, theyrelease acid substancesthat turnthe water a yellowishamber color.Although this is noproblem for Amazonianaquariums, this is not really thecase in waters that have to be kept hard.Secondly, wood is light and must bewedged or weighed down.• Treating wood before putting it into theaquariumThe treatment aims to:- free the wood of all animate material,especially those found in a natural setting:bacteria, fungi, and other undesirableorganisms;- help water penetrate the piece tomake it heavier;- free it of most of its acid substancesand colorings.First brush down the wood carefully,then disinfect it by soaking itfor 48 hours in:Wood can be held in place byscrewing it to a small stonebase. •• Rocks can betaken from naturalsettings, but theyare also availablein the aquariumtrade.265

TECHNIQUESWOODEN ELEMENTS USED IN AQUARIUM DECORBranches, rootsBarkPeat-bog woodOak, beech, and vines are all possibilities, especially if they have alreadyspent some time in water. Only use dead wood. Resinous wood is outof the question, as is wood washed up by the sea, which is saturated insalt.Use cork oak to decorate the side and rear panes of the tank, putting itin place with silicone glue.Also known as peat-bog roots. As the branches and roots have been inthis environment for a while, they rapidly release acid substances thatcolor the water.Natural orartificial? In reality,this marine decoris a mixture of thetwo, colonized byinvertebrates. •Bamboo- either bleach (1 ml/4 liters ofwater, using a concentrated sachet);- or copper sulfate, at 1 g/liter.Then boil the wood, replacing thewater several times. If the latter iscolored, this is proof that the acidsare leaving the wood. Ideally, thetreatment should be concluded bykeeping the wood submerged for 1or 2 weeks, so that it gradually fillsup with water.This is, however, often insufficient:the wood may still float and have tobe wedged into the aquarium withThese are attractive in an Asian aquarium, combined with plants withribbon-like leaves, such as Vallisneria.Coral skeletonsare one of theclassic elements ofmarine decor.266a few rocks. You can otherwise alsoweigh it down with small stones attachedby a nylon line that is all but invisible inthe water, hiding this part of the wood inthe sediment or else among other rockson the bottom.DECOR IN SEAWATER TANKSTropical marine fish live in an environmentlacking rocks but, on the otherhand, abundant in corals and other elementsthat can be used to form the decorfor an aquarium.CoralsCalcified coral skeletons can be used fordecor. They are often rough or sharpedgedand their stiffness depends onwhich species they belong to. They comein different shapes and sizes, and, with a

few rare exceptions, are whitish in color.Bleaching them results in a perfect white.In aquariums, dead corals often graduallyaccumulate a covering of green algae. Inthis case, wash and brush them underrunning water and then soak them inbleach (1 sachet of bleach for 10 liters ofwater) for 1 week. This will not onlywhiten the skeleton but also destroy anyorganic particles that may have settled init. Then rinse thoroughly and leave to dryin the open air for at least 8 days. Do notapply this treatment to corals from theTubipora genus with a colored skeleton.These must be cleaned with a soft brushin hot water and dried as above.Other elements ofanimal originGorgons produce a darkskeleton that often graduallydecays and evenends up crumbling. Theymust only be treated withhot water, never withbleach.It is also possible to usethe shells of mollusks(clams for example).Brush and wash them inhot water before puttingthem into the aquarium.Some aquarists considershells as potential trapsfor accumulated wasteproducts, but they canalso provide a refuge forsmall fish and, in thesame way, crustaceans.Live rocks can also play an important rolein the decor of an aquarium.ARTIFICIAL DECORModern artificial products are rapidlygrowing in popularity, especially in largefreshwater and marine aquariums. Theirmain advantage is the creative freedomthey give to a fishkeeper, making it possibleto choose decor that fits his or herexact requirements.Two main types of material are used:polystyrene and polyurethane. They areboth light and neutral.PolystyreneAvailable in blocks orsheets, it is usuallyused as a protectionagainst bumps andheat (in some householdelectrical appliances,for example).You can recycle it orbuy it in a store.Small-grained polystyreneis preferable as itis stiffen It is very lightand floats on water, soit must therefore befixed into the aquarium.Polystyrene canbe prepared to meetyour requirementsbefore putting it intothe tank.• Polystyrene decorUse a serrated knife orsmall saw to cut thecold blocks or sheets,or you can work withheated polystyrene,with a portable blowtorch or hot-air paintstripper. Be careful when handlingpolystyrene as it can melt, catch fire, andemit toxic vapors.The diagram on the following pageexplains how to make this type of decor.Cut a block in the size and shape youneed. If you are using sheets a few centimetersthick, you can heighten the reliefby putting several sheets on top of eachother. These are stuck together using resinmixed with sand. The design shown canbe completed with other pieces ofpolystyrene, which can partially mask theside panes.You can also combine sheets with large orsmall blocks. Then burn the parts that arevisible to give them a natural look. At thispoint natural elements such as rocks orcoral skeletons can be added, and resinand sand are applied to the structure(apart from the natural elements), beforeclearing up with a vacuum cleaner. Thiswhole process is usually completed outsidethe aquarium, as it is more practical,and the decor is then stuck to the glasspanes with silicone glue.DECOR AND BACKGROUNDGorgons have adark skeleton thatmakes anattractivedecorativeelement.267

TECHNIQUESPolyurethane isincreasingly usedfor decoratinglarge tanks. Hereit is combinedwith cork bark.268PolyurethanePolyurethane foamcan be made fromtwo componentsmixed together, but itis also available inaerosols that are morepractical. The productreleased rapidlyincreases in volumeand solidifies in a fewminutes. It can then be sculpted withsharp instruments.• Polyurethane decorBefore taking the plunge into the constructionof polyurethane decor, it isadvisable to watch somebody else performthe same operation first, to avoidmaking mistakes.In this case the decor must be createdinside the aquarium. If you have made thetank yourself, it is also more practical toput the decor in place before adding thefront glass pane, as this makes the processa lot easier.The aquarium needs minor preparationsbeforehand to receive the polyurethane:- stick small offcuts of glass, at intervals ofa few centimeters, in the places that willhold the decor;- another option is to make a mixture ofsand and silicone glue and deposit thismixture at regular intervals in the areas tobe decorated.Decor made ofpolystyrene sheets: theentire sheet can be placedvertically against the backof the aquarium.Then pour on thepolyurethane in smalldoses. You can workvertically to create adecor resembling acliff; it is also possible to incorporate rocks,pieces of dead coral, or cavities for plants.In tanks equipped with a box filter, do notforget the passageways for the water comingin and going out; these can be moldedon plastic pipes. The polyurethane driesvery quickly and can be sculpted with aknife or small saw, to give it a finish thatis more natural than its original smoothsurface. Finally, use a vacuum cleaner toremove the offcuts.TerracottaTerracotta decors, made from clay to imitatethe form of rocks, are commerciallyavailable from specialist suppliers.Although some hobbyists make their ownterracotta decor, polystyrene andpolyurethane are more common, largelyas a result of aquarium clubs and associationsthat offer guidance to beginners inthese techniques.• Making a terracotta decorContact a tile or flowerpot factory toobtain the raw material and to get it fired.Use clay, which is neutral and malleable.For a medium-sized decor, calculatearound 100 g of clay per liter of volume,but only practice or the advice of moreexperienced aquarists will offer you moreprecise indications.Model the clay in accordance with thedecor you want:- rocks of varying sizes;- rocky cliff or slope;- grottoes, arches.The end results should have a natural look.All the elements must be dried in the openair and then fired in an oven at 800-900°C.This reduces their weight by 25-30% andendows them with a color resembling tiles.A final option is the application of resinand sand on the surfaces of the decor.

ResinThis allows you to polish the decor. It ispossible just to use artificial decor withouttreating it and wait until it acquires apatina after being in the tank for a fewmonths. However, most hobbyists preferto give it a natural appearance by incorporatinga range of materials: sediments ofvarying textures, such as sand, gravel,coralline sand, or pieces of rock or coral.To make these adjustments, a so-calledfood resin, epoxy resin, is used, as it hasno influence on the water. It is made upof two components which harden whenthey are mixed together, and it can be coloredto look more natural.DECOR AND BACKGROUNDEXTERNAL DECORAt first sight, it may seem surprising to talkof external decor. However, there is nothingmore unsightly than the sight of thewall behind the aquarium covered withcables and pipes! The primary role ofexternal decor therefore consists of maskingthese elements, but it can also serve tohighlight the plants and fish.PostersPosters with various designs, representingfreshwater vegetation or seabeds, can befound in aquarium stores, but manyaquarists remain unimpressed by theirvisual effect. They are attached to theouter face of the rear pane.Colored backgroundsAn alternative to posters is sheets in a singlecolor, such as blue, green, gray, pale• Resin applied topolyurethane canbe dyed with foodcolorings, in thiscase a mixture ofred and black.FINISHING ARTIFICIAL DECOR: RESIN AND SANDResin and sand completely insulate the decor from the water and give it a natural look. The sandused must be in keeping with the type of aquarium - freshwater or marine - and match the sediment.If you use fine sand, you will need to apply several layers.• Polystyrene or terracotta decorThe resin and sand are added outside the aquarium. A coat of resin is applied with a paintbrushand sand is then sprinkled on top. Leave to dry (24 hours for the layer of resin) and repeat the operation1-3 times, depending on the sand's grain size.It is important to apply the resin carefully over all the decor, without neglecting any small reliefs,crevices, or grottoes. Only resin, without any sand, should be put on those parts of the decor thatwill be touching the glass panes of the aquarium.Remove any leftover sand, firstly with a large paintbrush, and then with a vacuum cleaner. The finisheddecor is stuck to the aquarium with silicone glue, 48 hours after drying.• Polyurethane decorFollow the same process with the polyurethane set in the aquarium, and do not forget to applyresin and sand to the joins between the decor and the glass panes. Any leftover sand is removedwith a vacuum cleaner.269

TECHNIQUESbrown, or black. Black highlights fish andplants particularly effectively. A fewaquarists paint a color scale themselves,pale at the top of the aquarium and darkerat the bottom, to simulate the penetrationof the light. Another option is to paintdirectly onto the back of the rear pane.STIMULATING THE IMAGINATIONThe imagination is a capricious spirit that can sometimesdesert you. You want to create your own decor, you havebeen dreaming about it ... but your mind goes blank! There are,however, several sources of inspiration:- other aquariums, friends, clubs, public aquariums;- books and specialist magazines;- but also - and above all! - nature. Photos and sketches will helpyou to translate your ideas into reality, particularly as to how reliefscan be harmonized.• The rear pane in this tank has been replaced by amirror, to produce a striking effect.MirrorsAlways placed behind the rear pane, thesegive the impression that the tank is twiceits initial size... but also that is has doublethe number of plants and fish!Other possibilitiesA polystyrene sheet with a coat of resinand sand can be placed against the outsideof the rear pane.Finally, you can consider putting naturaldecorative material, such as rocks,branches, and roots, behind the aquarium,in front of a black cardboard backdrop.These elements can be simply wedgedtogether, glued, or held down with adhesiveclay. The overall effect is to increasethe depth of field, for when an aquariumis full it seems one third smaller, becauseof the refraction of light in the water. Thistype of decor can easily be changed,needs no prior treatment and very littlemaintenance, the only disadvantage beingthat it accumulates dust.• There are countless sources of inspiration if you want to create adecor but find that your imagination has failed you.270

DECOR AND BACKGROUND271

FINAL PREPARATIONSInstalling an aquarium requires cool nerves and good organization. It is useless to rush, asyou may end up spoiling the final results. Note that the aquarium will not be ready toreceive fish as soon as it is put into operation, especially if you are using sea water. So,patience is called for!Putting theunder-gravel filterin place, ready toreceive thesediment. Thewater exit must bepositioned in oneof the aquarium'srear corners. •272HOW TO PROCEEDThe steps to be taken when setting up anaquarium have a logical order, and thismust be respected. These steps varyslightly according to whether fresh wateror sea water is being used, but the underlyingprinciple is the same: water is notpoured into the aquarium until the decor,bed, and the necessary technical equipmentare in place.Installation, step by stepThe order is as follows:1. Cleaning the tank. Use a brand newsponge and warm water. It is best to avoiddetergents.2. Fitting the external decor (see page264). Make sure that this is put firmly inplace, otherwise it will be difficult to fixlater on.3. Mounting the aquarium on its support.Remember that the support must beabsolutely horizontal and covered with aflexible material that will compensate forany possible unevenness. At this stage,make sure that you leave sufficient spacebehind the tank to allow you easily toopen the gallery and the entrance thatgives access tothe pipes andcables. Theaquarium willnot be movedagain afterthis point.4. Fill thetank, to makesure it is watertight.Leaks are rareoccurrences;a slight seepageis morecommon, although this can only bedetected about 24 hours after putting inthe water. When you are sure your aquariumis watertight, siphon out the water.5. If you are using an under-gravelfilter, position it so that the air-lift is inone of the tank's rear corners.6. Installing the accessories. Placethese directly into the tank or in the boxesof the box filter. The heating system mustnot come into direct contact with anyplastic elements, and it must be near thediffuser. If you are using an external filter,do not forget the connecting pipes.7. Putting the decor in place. Introducethe rocks or corals, taking into accountboth the visual and practical aspects andmaking sure to hide the accessories.Take your time and experiment until youare happy with the overall aesthetic effect.Once you have filled the aquarium, youare unlikely to get another chance to makeadjustments to the decor8. Putting in the bed. Half the sedimentis placed directly on the bottom of thetank, without any prior washing. The secondhalf isrinsed inwarm wateruntil the latter istransparent. It isthen put on topof the firstlayer. Makesure that theelements of thedecor are firmlywedged intothe bed. Someof them can beused to createraised sandyterraces at thispoint.

For aesthetic reasons, the sediment shouldslope downwards slightly from the backto the front of the aquarium: this gives theimpression of a greater depth of field.9. Filling the tank. Whatever methodyou use - a pipe connected to a faucet orbuckets - break the fall of the water toavoid dislodging part of the sediment. Thetime-honored trick is to pour the waterinto a bowl or concave plate.The aquarium must not be filled to itsmaximum height, as you may need tomake corrections in the decor if, forexample, a piece of wood starts to float.You can also put in your plants now.The water will be slightly cloudy, withmicroparticles on the surface that can beeliminated with a very fine-meshed landingnet, or through siphoning.10. Switching on the equipment. Firstcheck that the heating element is totallysubmerged, then turn on the heating andregulate the temperature to 25°C. Plug theaeration and filtration systems into themains. A quick glance will be enough tocheck that everything is working and aftera few hours the water should have heatedup and be clearer.• A tank must be filled with care, to avoidknocking over any decor.11. Wait for another 24 hours, thenrecheck that the equipment is working.The water must now be clear, with atemperature around 25°C. It is sometimesnecessary to make slight adjustments tothe regulation of the thermostat to obtainthe desired temperature. You can nowadd any other vegetation.Operations specific to marine aquariums.The process is identical up to stage 6. Thisis when you must install the aerator andthe UV sterilization system.Put the decor in place and then add thebed. The latter must all be washed beforehandand then placed on a thin layer ofsediment. After that, fill the aquarium withthe freshest water possible; only switch onthe aeration. Now is the time to dissolvethe salts. Weigh the amount you require,on the basis of the realvolume of the water,before putting them intothe aquarium. Leave thesalts to dissolve for 48hours, check the density,and make the necessaryadjustments. Then moveto stage 10, withoutswitching on the aeratoror UV system, beforecontinuing to stage 11.FINAL PREPARATIONSThe sedimentcovers the undergravelfilter, andthe heating andaeration equipmentmust becamouflaged.The vegetationcan be planted byhand, or withspecially designedpincers.Introducing plants• Source of plants andtransportationPlants can be obtainedfrom aquarium storesand clubs, or they canbe a present from afriend. Wherever theycome from, do not forget273

ARRANGING YOUR PLANTSWhen you plant your first aquarium, it is advisable tostick to a classical style and opt for an amphitheater layout.Distribute the plants that grow quickest along the sides and backof the tank; put those that grow at a moderate rate directly infront of them, with the smallest in the foreground.This arrangement leaves space free in the center of the aquariumand gives a good impressionof depth of field.The arrangement of yourplants must be visuallypleasing, but also respecttheir ecology. •Live rocks and theorganisms theycarry enhance thefunctioning of amarine aquarium.•that they are very fragile when handledoutside water.The best way of transporting them withoutany deterioration is to put them into an airtightplastic bag, like those used for fish,that has been inflated and sealed.• PlantingYet again, it is a question of satisfying bothaesthetic and technical criteria. A smallground plan of the aquarium can be usefulin achieving a successful layout, taking intoaccount the species available.Generally speaking, plants of the sametype should be grouped together, settingoff any isolated specimens.Handling the plants with great care, start atthe back of the aquarium and, above all,do not let your desire for a lush setting leadyou to pack the plants too tightly together;it is best to space them out, even if theresulting vegetation looks sparse. There arethree main reasons for this:- the roots must have sufficient space inwhich to expand;- you must also in bear in mind that theplants will grow and maybe spread outtheir leaves;- finally, you must allow the light to penetrateto the base of the plants.Do not cut the already existing roots, orbunch them together; on the contrary,spread them out as much as possible in thesediment. You should not bury clumps ofplants very deep; only the roots and thelowest (often white) part of the stemshould be covered by the sediment.When planting cuttings, remove any damagedleaves at the base of the stem thenbury them to a depth of 4 or 5 cm. This iseasier if you dig a small hole first with yourhand or an appropriate tool, and pile soilaround the base of the plant at the end ofthe operation.Plants like moss and ferns must be placedon the supports to which they are going toattach themselves. They will stay in placemore easily if they are wedged or tied witha short length of nylon thread. Put floatingplants on the surface of the water.Do not be surprised if the plants look limp.They will quickly take on a normal appearancewhen the lighting is switched on, asthe attraction of the light will make themstraighten up. From this point on, theaquarium must be lit in accordance withthe recommendations that are given onpages 226-233.All that remains is to raise the water levelto its final position and ... wait, beforeintroducing the fish.Preparing the welcome for your fishThe only thing your aquarium now lacksto be complete is the arrival of its residents... Summon up your patience one lasttime, because the aquarium has yet toacquire a perfect equilibrium: the plantsmust take root and bacteria must developfor the nitrogen cycle.• A gradual introductionThe minimum waiting period for a freshwatertank is 1 week, but 2 weeks is prefer-274

FINAL PREPARATIONS• Patience is required to achieve results as beautiful as this in a marine aquarium.able. In the case of a seawater tank, the waitcan sometimes be as long as 4 weeks. If youreally cannot hold out that long, there areseveral ways of reducing this period. As wehave already stated, the aim of this waitingperiod is to allow bacteria to develop and toavoid the presence of any toxic nitrogenoussubstances, so you can speed up this developmentartificially. The first short cut isgood oxygenation - the bacteria need oxygento respire and to transform the nitrogenouscompounds - the second is theintroduction of bacteria. This can beachieved by adding sediment or filteringmaterial from another marine aquarium,sand, live rocks, or lyophilized bacteria,which can be bought in specialist stores.However, this last solution is not recommended,as it sometimes proves ineffective.Another alternative is to become a breederof bacteria, feeding them on organic matterthat they would not otherwise obtain in atank that has been newly put into operation.The best menu comprises one or twocooked mussels, cut into small pieces andplaced in the aquarium, with any leftoversbeing siphoned off a few days later.Such measures can reduce the waitingperiod to 8-10 days. However, the nitritelevels must always be measured regularly,and no fish must be put into the tank untilthese levels have been stable at zero for275

TECHNIQUESSpecialist storesoffer a wide rangeof fish species,including thosesuitable fornovices.276around 1 week. Only then can you switchon the aerator and UV sterilization (inmarine tanks only).• Choice of fishThe choice of residents depends on thetype of tank (community, regional, or specialist),your tastes, and your budget. Thenumber of species available on the marketis more than sufficient for most fishkeepers,especially novices. A quick inspectionof a few stores will give you a broadoverview and enable you to make a welljudgedselection.There are some rules, however, that mustbe respected if you are to avoid resultsthat are too often found: a "hold-all"aquarium, overpopulated with a motleycollection of species. It is best to choose afew species and keep them in groups -this is possible for a great many species.Respect their natural behavior, as thisincreases the probability of eventualreproduction. However, aggressive speciesthat usually live alone must obviously bekept as single specimens.You can take advantage of all the differentlevels of the tank by combining freeswimmers with bottom- and surfacedwellersthat can live in harmony.There remains the problem of livingspace. The general rule, for small species,is 1 cm of fish per liter of fresh water and1 cm per 5 liters of sea water. The tableabove presents some more precise calculations,but you must bear in mindthe maximum length that eachspecies can attain in an aquarium.Acquisition and transportObviously, a fish must have a cleanbill of health when it is introducedinto an aquarium, and there arecertain signs that indicate this.There is still a risk of an unpleasantsurprise, however, as some fish arecarriers of diseases that only comeinto the open once they are putinto an aquarium.Whether a fish comes from a store,a club, or a friend, it must alwaysbe scrutinized carefully beforeacquiring it. This is why you must

not be in too much of a rush and shouldget to know a storekeeper or join a club,to look and learn. When you do finallyintroduce fish into the aquarium, youmust adopt a particular strategy:- It is best to populate the tank in one go,or at most in two, with a short intervalbetween, rather than introduce the fishone by one. A newcomer, by definition, isperceived as an undesirable alien, whichcan give rise to conflicts that sometimesresult in its death.- If you are obliged to stagger the introductionof the fish over a period of time,it is best to start with smaller species andallow them to get accustomed to theirenvironment; in this way, they will not beso alarmed by the subsequent arrival ofbigger species.Fish are quite easy to transport. Just put asmall group into a closedplastic bag containingone third water andtwo thirds atmosphericair. In thecase of species withspiny spokes, youcan add a secondplastic bagfor protection.This system iseffective for ashort trip, ofone or twohours, dependingon the external temperature. Afterthat, heat starts to be lost, although thiseffect can be reduced by surrounding theplastic bag with material or paper andputting it in a polystyrene bag.Transferring your fish into an aquariumThe fish will be stressed when it is introducedinto its new home, on account ofthe transportation, the radical change ofenvironment, and the difference in waterquality. To alleviate this stress, you mustnever introduce a fish directly into a tank.Proceed in stages, allowing a minimum of1-2 hours for the whole operation. Forthe first 30 minutes, just let the bag containingthe fish float in the aquarium tomake sure that the temperature is thesame in both cases. Then open the bagand put a little water from the aquariuminside. Repeat this operation several timesat regular intervals until the bag is full.You can then carefully transfer the fishinto its new environment.If there are already fish in the aquarium,you must take two extra precautions toincrease the chances of the newcomersbeing accepted: distract the attention ofthe other occupants by giving them food,and introduce the new arrivals in themorning, before lighting up the tank.In any case, the new fish is likely to hidefor a while, and this is a completely normalattitude. When it reemerges willdepend on its nature, but it sometimesreappears after barely an hour. Some maytake longer to acclimatize, however.It will soon grow accustomed to its newenvironment and the feeding schedule,and will become completely integratedinto the aquarium. If the fish is healthyand you take all the necessary precautions,mishaps are very rare and the ecologyof the aquarium will not be upset.The bag used fortransporting fishmust be left tofloat for a while, toensure that itstemperature is thesame as that of thetank.Fish must betransported inairtight bagscontaining more airthan water.The bags usedfor transport mustbe insulated forlong trips to avoidany loss of heat.277

CUSTOMIZINGCENTRAL AMERICAN FRESHWATER TANKThis type of aquarium, particularly suitable for beginners, reconstitutes a freshwater Central Americanenvironment. The fish living in it (the Poeciliid family) will soon reproduce if the conditions are right.It is advisable to provide yourself with a rearing tank, to help the fry develop. You can then move on tothe true livebearers coming from the same geographical region: Anieca splendens and Xenotoca eiseni. Theplants shown here grow fairly quickly and it is easy to take cuttings from them; they are therefore a goodmeans for taking your first steps in plant decor, which is sometimes neglected by beginners at the expenseof fish until they realise the importance of vegetation.

YOUR TANKSOUTH-EAST ASIAN TANKThis tank must be well planted, but with enough room for the fish to move around. You can add atouch of originality by introducing some transparent species: the glass perch (Chanda ranga) or theglass Silurid (Kryptopterus bicirrhis). A small shrimp (Atya or Macrobrachium) and gastropods(Ampullaria) can complete the population: the visual effect of the plant decor will be highlighted by theaddition of a single specimen of a spectacular specimen, such as Barclaya longifolia or a species fromthe Nymphaea genus available from specialist nurseries.

CUSTOMIZINGAFRICAN CICHLID TANKThe absence of plants in an African Cichlid tank can be compensated by a rocky decor that providesthe fish with shelters and hiding places; polyurethane and polystyrene can also prove very effectivefor fulfilling the same purpose.For Lake Tanganyika, you can introduce the Cyprinodontid Lamprichthys tanganicanus or a species ofLamprologus, which takes refuge in a gastropod shell. For Lake Malawi, you can add species of theHaplochromis genus. These reproduce through mouth brooding, ensuring that the hobbyist can lookforward to a fascinating spectacle once he or she has spotted a female with her mouth swollen by eggs.Rocks

YOUR TANKMARINE TANKThis marine tank represents a basic model for a beginner in sea water. The species proposed arerobust, and their behavior provides a fascinating show, particularly the clownfish in their anemone,which may be able to reproduce.To diversify the animal population, you can add a shrimp or a hermit crab. It is also advisable to put inlive rocks, which will contain small invertebrates. An artificial decor that includes coralline sand and evensmall pieces of coral is pleasing to the eye, and can be colonized by caulerpas. This type of aquariumrequires impeccable water quality to guarantee its equilibrium.

USEFUL INFORMATIONBIBLIOGRAPHYDr. Axelrod's Atlas of Aquarium Fishes, Herbert R. Axelrod,Warren. E. Burgess, Neal Pronek, and Jerry G. Walls, T. F. H.A Fishkeeper's Guide to Aquarium Plants, Barry James, SalamanderBooks.A Fishkeeper's Guide to Fish Breeding, Chris Andrews, SalamanderBooks.The Hobbyist's Guide to the Natural Aquarium, ChrisAndrews, Tetra Press.A Popular Guide to Tropical Aquarium Fishes, Dick Mills,Salamander Books.The Practical Encyclopedia of the Marine Aquarium, DickMills, Salamander Books.Reef Fish: Behaviour and Ecology on the Reef and in theAquarium, Ronald E. Thresher, Bartholomew.Our Native Fishes: The Aquarium Hobbyist's Guide to Observing,Collecting and Keeping Them. North American Freshwaterand Marine Fishes, John R. Quinn, The CountrymanPress.The Optimum Aquarium, Kaspar Horst and Horst Kipper,Aqua Documenta.The Book of the Marine Aquarium, Nick Dakin, SalamanderBooks.A Guide to American Zoos and Aquariums, Darcy and RobertFolzenlogen, Willow Press.A Practical Guide to Corals for the Reef Aquarium, DeanPuterbaugh and Eric Borneman, Crystal Graphics.The Reef Aquarium, Volumes One and Two, Julian Sprungand J. Charles Delbeek, Ricordea Publishing.USEFUL ADDRESSESResourcesCatalog of Fish Species:www.calacademy.orgPlants:www. tropica.comInvertebrates:www. netvet.wustl.eduGeneral Information:www.petswarehouse.comwww.actwin.com/fish/index.cgiAquarian Advisory Society, PO Box 67, Elland,West Yorkshire HX5 OSJ.Public AquariumsSteinhart Aquarium, San Francisco, California.E-mail: aquarium@calacademy.orgFlorida Aquarium, Tampa, Florida.E-mail: srichardson@flaquarium.orgNew England Aquarium, Boston, Massachussets.E-mail: webmaster@neaq.orgAksarben Aquarium and Nature Center, Louisville, Nebraska.E-mail: akaq@ngpc.state.en.usDeep-Sea World, Fife, ScotlandE-mail: deepsea@sol.co.ukLondon Aquarium, London, England.E-mail: info@londonaquarium.co.ukAssociationsAmerican Zoo and Aquarium Association, 8403 ColesvilleRoad, Suite 710, Silver Spring, MD, USA.American Aquarist Society, 3901 Hatch Boulevard, Sheffield,Alabama, USA.International Aquarium Society, PO Box 373, Maine, NY13802-0373, USA.Federation of American Aquarium Societies, 4816 E. 64thStreet, Indianapolis, IN 46220-4728, USA.North American Fish Breeders' Guild, 905 Alden, Lansing,Michigan 48910, USA.North American Native Fishes Association, PO Box 2304,Kensington, MD 20891, USA.Aquatic Gardeners' Association, 83 Cathcart Street, London,England.International Marine Aquarist Association, PO Box 7, Ilminster,Somerset TA19 9BY, England.Federation of British Aquatic Societies, 2 Cedar Avenue,Wickford, Essex SS12 9DT, England.The Association of Aquarists, 2 Telephone Road, Portsmouth,Hampshire, England.CONVERSIONSCapacity:1 L = 0.22 UK gal/0.26 US galWeight:1 mg = 0.04 x 10 -3 oz1 g = 0.04 oz1 kg = 2.2 lbLength:1 mm = 0.04 in1 cm = 0.39 in1 m = 33 ft or 1.1 yd1 km = 0.6 mTemperature:°C °F10 50.0II 51.812 53.613 55.414 57.215 59.016 60.817 62.618 64.419 66.220 68.021 69.822 71.623 73.424 75.225 77.026 78.827 80.628 82.429 84.230 86.0To convert Celsius into Fahrenheit: ( 9 / 5 x °C) + 32282

AAbsence of aquarist, 33, 257Abudefduf saxatilis, 145, 146Acanthaceae, 204Acanthodoras spinosissimus,92Acanthophthalmus, 72, 89kuhli, 72, 88kuhli kuhli, 89kuhli sumatranus, 89myersi, 89semicinctus, 89Acanthopsis choirorhyncus, 89Acanthuridae, 150, 178Acanthurusachilles, 150japonicus, 150leucosternon, 150lineatus, 150soha/, 151AcaraBlue, 110Red, 118Acidity, 13Acorus, 202, 214calamus, 202Dwarf, 202gramineus, 202Green, 202Acropora sp., 184Acroporids, 184Actinia, 182Actinia equina, 144Actinodiscus sp., 184Active carbon, 246, 247, 250cornutus, 128spinifer, 128Aequidens, 105curviceps, 105, 110maroni, 105, 110pulcher, 105, 110Aeration, 62, 199, 235, 236,237, 259, 273Aglaonema, 211Aiptasia, 135, 183Air distribution pipe, 236Air-lift, 239, 240, 242, 243, 272Algae, 36, 38, 50, 165, 166,169, 170, 175, 177, 192, 193,195,200,226,232, 233,236,252, 258, 264filamentous, 198Mediterranean, 214micro-, 56, 165, 168, 169,170planktonic, 56proliferation of, 195undesirable, 194Algae-eater, Chinese, 92Alcyonaria, 185Alcyoniidae, 185Alkalinity, 13Alismataceae, 206, 209Alternanthera, 207, 214reineckii, 207sessilis, 207Amaranthaceae, 207Amaryllidaceae, 213Amazon, 209Dwarf, 209Giant, 209Pygmy, 209Ambuliaaquatic, 205heterophyllous, 205Ameca splendens, 103Ammonia, 19,20,21,22,27,171, 193, 251Amphibian, 33Amphiprion, 142akallopisos, 142bicinctus, 142, 183clarkii, 143ephippium, 142frenatus, 143ocellaris, 143percula, 143perideraion, 143sebae, 143Ampullaria, 166, 180, 279fir/gas, 180Anabantidae, 37, 120Anampses chrysocephalus,148Anampses, Red tail, 148Anatomy, 42, 46Ancanthuridae, 193Ancistrus sp., 92, 192, 193Anemone, 24, 38, 142, 143,145, 164, 167, 169, 170, 171,174, 175, 192, 232,250,264,281associated with clownfish,144colonial, 183discus, 184glass, 183sea, 182Angelfish, 44, 73, 108, 136African, 137Annularis,Asfur, 139Bicolor, 140Black velvet, 136Blueface, 136coloring of juveniles, 137Deep, 108Dwarf, 140Eibl's, 140Emperor, 138Flagfin, 139Flame, 141Flame back, 141French, 138Gray, 138Gray poma, 139Half-black, 141Indian ocean, 139Japanese swallow, 139Lamarck angel, 139Lemonpeel, 141Majestic, 137Potter's, 141Purple moon, 138Queen, 137, 138Raccoon, 138Rock beauty, 137Rusty, 140Singapore, 136Yellow, 141Animal-flower, 164Anisotremus virginicus, 154Annectens, 116Annelida, 175Anoptichthys jordani, 46, 76Anostomidae, 80, 81Anthozoa, 164, 169, 170,171, 175, 182, 183,229, 230,231, 232, 249, 263, 264Anthia, 61Scalefin, 130Anthilidae, 130Antibiotics, 68AnubiasBarter's, 208Congo, 208Dwarf, 208Anubias, 35, 208,214barter!, 208heterophylla, 208Aphyocharax anisitsi, 76Aphyosemion, 96australe, 96bivattatum, 96gardneri, 96Gery's, 98marmoratum, 96sjoestedti, 96Two-striped, 96Walker's, 96walkeri, 96Apistogramma, 64, 105, 109agassizi, 110cacatuoides, 110ramirezi see Papiliochromis r.Aplocheilus, 97lineatus, 98panchax, 98Apogonidae, 159, 178Apolemichthystrimaculatus, 139xanthurus, 139Aponogeton, 212, 214crispus, 212fenestralis, 212henkelianus, 212madagascariensis, 212Madagascar laceleaf, 212ulva, 212ulvaceus, 212Aponogetonaceae, 212Aquariumfilling of, 220final preparations of, 272hospital, 38, 66,68, 69,71,178,260introduction of fish into, 277quarantine, 71regional, 202temperate water, 214Aquaterrarium, 202, 214Araceae, 202, 208, 211, 212Archer fish, 125Arothroncitrinellus, 157hispidus, 157meleagris, 157nigropunctatus, 157Arrowhead, 206, 207Narrow leaf, 206Artemia salina, 55, 56Arusetta asfur, 139Aspidontus taeniatus, 147Astatotilapia, 105burtoni, 105, 118Astronotus ocellatus, 110Atherinidae, 94Atya, 181,279moluccensis, 181Aulonocara nyassae, 105,114,280Bacopacaroliniana, 202monnieri, 202Bacteria, 13, 15, 19,20, 21,29, 54,67,70, 172, 177, 193,238, 240, 247, 249, 258, 260,263, 265, 274, 275Balantiocheilus melanopterus,88Balistapus undulatus, 153Balistes vetula, 153Balistidae, 153, 178Balistoides conspicillum, 153Bamboo, 266Barb, 35, 37, 48, 49, 72, 82,83, 279Black ruby, 82, 83Checker, 82Cherry, 83Clown, 83Five-banded, 83Golden, 83Green, 83Half-striped, 83Rosy, 82Schwanenfeld's, 82Spanner, 83T-barb, 83Tiger, 18,82,83Tinfoil, 82Barbel, 45, 155, 262Barbodes everetti, 83pentazona, 83Barbusoligolepis, 72, 82pentazona, 83schwanenfeldi,72,82Barclaya, 213, 214longifolia, 213, 279Basalt, 265BassDwarf, 158True, 158Batfish, 159Bed, 260, 262, 272enriched, 262Bedotiageayi, 94Belontiidae, 47, 65, 120, 121Betta splendens, 43, 120Biotope, 32, 33, 34, 35, 48,178, 221,265Bivalves, 165, 166, 176, 186Blennie, 161Blenniidae, 161, 176, 178Blockhead, African, 119Bloodfin, 76Glass, 79Bodianusmesothorax, 148rufus, 148Bolbitis, 210, 214heudelotii, 210Botia, 45, 49, 72, 279horae, 89lohachata, 89macracantha, 89modesta, 89striata, 89Boxfish, 155Spotted, 155Yellow, 155Brachydanio albolineatus, 84frankei, 84rerio, 84Brachygobius xanthozona,124Branchiae, 45, 46, 47, 70, 266Breeds, strains, and varieties,73Brine shrimp, 55, 56, 57, 58,175Bristlenose, 92Bromide, 26Bubble-eyes, 87Bubble nest, 65Bumblebee fish, 124Butterfly fish, 122, 132, 183,184Auriga, 132Banded, 135Black and white, 135Black back, 133Copperband, 134Dot-dash, 134Four-spot, 134Lemon, 133Longnose, 135Masked, 134Meyer's, 133Pakistani, 133Pennant, 135Raccoon, 133Red Sea, 133Red-tailed, 132Spot fin, 134Vagabond, 135Cabomba, 64, 199, 203, 214,278aquatica, 203water, 203Cabombaceae, 203Calcium, 15, 16, 17,26,28,30,53, 166, 168, 171, 172,173, 247, 251, 254, 263, 265Callichthyidae, 90Callionymidae, 159, 178Calloplesiops altivelis, 158Canthigastermargaritatus, 156valentini, 156Canthigasteridae, 156, 178Capoeta, 72schuberti, 72, 83semifasciolatus, 83tetrazona, 18, 83titteya, 73, 83, 279Carassius auratus, 33, 86, 87Carnegiella strigata, 81Cardinals, 159, 178Carp, 82, 86, 87Common, 33Koi, 33, 87Catfish, 42, 90,91, 155Aeneus, 91Bandit, 91Black-bellied upside-down, 93Bronze, 91Ghost, 93Glass, 93Leopard, 91Shovel-nose, 92Skunk, 89Spotted, 90Striped, 155Talking, 92Three-striped glass, 93Twig, 92Carbon dioxide, 12, 13, 14,15,26,46, 169, 192, 196,197, 199, 235,251,254, 259,265Caryophylliidae, 184Caulerpa, 192, 200, 215, 264,281Feathery, 215Mediterranean, 215prolifera, 169,215, 281sertularoides, 215, 281taxi folia, 215Caulerpaceae, 215Centropomidae, 123Centropygeacanthops, 140bicolor, 140eiblii, 140ferrugatus, 140flavissimus, 141heraldi, 141loriculus, 141potteri, 141vroliki, 141Cephalopholis283

argus, 130miniatus, 130urodelus, 130Ceratophyll, 203Ceratophyllum, 203, 214demersum, 203Ceratopteris, 214cornuta, 210thalictroides, 210Cerianthus sp., 183Chaetodermis penicilligerus,160Chaetodon, 132aur/ga, 132, 281capistratus, 133, 135chrysurus, 132collare, 133fasciatus, 133lunula, 133melannotus, 133meyeri, 133miliaris, 133ocellatus, 134punctatofasciatus, 134quadrimaculatus, 134semilarvatus, 134vagabundus, 135Chaetodonplusmelanosoma, 136mesoleucus, 136Chaetodontidae, 132, 135,178, 183, 193Chanda ranga, 123, 279Characidae, 35, 42, 49, 63,64, 76, 80, 90, 108, 109, 192South American, 203Cheirodon axelrodi, 76Chelmon rostratus, 134Chlorine, 26Chlorophyceae, 194, 215Chlorophytum, 211Chromide,Banded, 119Orange, 119Chromis caerulea, 145Chrysiptera paresema, 145Cichlasoma, 62, 105, 106bimaculatum, 105, 107biocellatum, see C. octofasciatumcitrinellum, 106crassum, 105, 106cyanoguttatum, 107festivum, see Mesonautafestivuslabiatum, 73, 107maculicauda, 106mee/c/, see Thorichthys m.nicaraguense, 107nigrofasciatum, 108octofasciatum, 107salvini, 106synspilum, 108CichlidAgassiz's dwarf, 110Banded, 108Blackbelt, 106Chameleon, 117Chocolate, 105, 106Cobalt blue, 117Cockatoo dwarf, 110Convict, 108Crown jewel, 118Festive, 107Firemouth, 107Five-barred, 113Flag (Aequidens curviceps),110Flag (Mesonauta festivus),107Fuelleborn's, 116Golden dwarf, 111Keyhole, 110Lemon, 113Lionhead, 119Malawi blue, 117Malawi golden, 116Midas, 106Pearl, 111Ramirez's dwarf, 110Redheaded, 108Salvin's, 106Texas, 107Trewavas Malawi, 116Triangle, 111Two-spot, 107Cichlidae, 34, 35, 36, 44, 49,60, 64, 73, 104, 235, 244,261, 264African species, 111American species, 106Asian species, 119behavior of, 105breeding, 105fact and fiction concerning,104Cirrhitidae, 160, 178Classification of living beings,72Clay, 246, 247CleanerFalse, 147True, 147Cleaningof glass panes, 253of tank, 272with scraper, 252, 254Clownfish 61, 65, 142, 167,182, 281associated with anemone,144Clark's, 143Maroon, 143Ocellaris, 143Pink skunk, 142Red saddle, 142Seba's, 143Skunk, 143Tomato, 143Two-banded, 142Cnidaria, 171Cobitidae, 72, 88, 89Cockle, 52Codiaceae, 214Codiumbursa, 214Felt, 214Felt ball, 214vermilara, 214Coelenterates, 164, 167, 169,170, 171, 174, 175, 176, 177,178, 182, 185Colisa chuna, 120fasciata, 120labiosa, 120lalia, 120, 121sofa, see C. chunaColor scale, 14Colored background, 270Coloring, 44Community tank, 62of African Cichlids, 280marine, 281rearing, 221, 278South-East Asia, 279Condylactis gigantea, 144Copadichromis boadzulu, 114jacksoni, 115Copper, 21sulfate, 68, 69, 71, 195,266Coral, 24, 26, 28, 38, 42, 44,45, 164, 167, 168, 170, 171,172, 173, 177, 183, 192, 194,228, 232, 250, 263, 266, 268,269, 272, 281Bubble, 184crushed, 263dead, 168Leather, 185Red, 185sand of, 168Soft, 185True, 184Corallimorpharia,Corallium rubrum, 185Corisangulata, 146formosa, 146gaimard, 147Corydoras, 45, 90, 91, 94,108, 109aeneusarcuatus, 90Black-sail, 90Black-spotted, 90julii, 91melanistius, 90metae, 91paleatus, 91Peppered, 91punctatus, 90Schwartz's, 91schwartzi, 90, 91Three-line, 90trilineatus, 90Cowfish, longhorn, 155Crab, 166, 176Lobster, 177Crawfish, 166, 181Louisiana, 181Crinum, 213, 214natans, 213Crinum, aquatic, 213Cromileptes altivelis, 130Crossbowman, 153Crustaceans, 16, 28, 50, 56,164, 165, 166, 174, 176, 177,178, 181, 186,267Cryptocaryon disease, 70Cryptocorynebalansae, 208Balansa'sbeckettii, 208Beckett's, 208ciliata, 208Ciliated, 208cordata, 208, 279crispatulaSiamese, 208Undulated, 208Cryptodendrum adhesivum,144Ctenaria, 171Cuttings, 199, 200Cyanophyceae, 194Cynolebias, 97bellottii. 97nigripinnis, 97Cyperaceae, 204Cyphotilapia frontosa, 105,111Cypraea, 186geographical, 186mappa, 186tigris, 186Cyprinidae, 35, 72, 82, 88Cypriniformes, 72Cyprinodontidae, 63, 95, 261,280Cyrtocara moorii, 115DamselAzure, 145Black-tailed, 146Blue, 145Blue-green, 145Domino, 146Electric blue, 145Three-stripe, 146Danio, 35, 49, 82, 84, 279aequipinnatus, 84Giant, 84Leopard, 84Pearl, 84Striped, 84Zebra, 84Daphnia, 53Dascyllusaruanus, 146trimaculatus, 146Daylight, 228, 229, 230, 231Decor, 66, 67, 191, 192, 193,194, 219,225, 264,272, 273,274artificial, 267, 271, 280,281exterior, 269Decoration, 200, 218Deflector, 195Dempsey, Jack, 107Dendrochirus zebra, 152Dendrophylliidae, 184Density see Specific gravityDermogenys pusillus, 103Devil, 146Red, 107Diatom, 194Diffuser, 26, 65, 194, 197,234, 235, 236, 237, 240, 250,252, 253, 256, 272Digestive system, 47Dimidiochromis compressiceps,115Diodon hystrix, 156Diodontidae, 156, 178Discus, 35, 90, 109, 244color varieties of, 109Heckel, 109Diseases, 66, 67, 69,71, 276bacterial, 68non-infectious, 67treatment of, 67Dogface, 157Dollar, Silver, 81Doradidae, 92Dracaena, 211Dragonette, 159Drip, 255, 256Dropsy, 70, 71Duboisi, Blue-faced, 114Duckweed, 210Echidna nebulosa, 148Echinoderms, 165, 177, 178Echinodorus, 108, 200, 209,214amazonicus, 209Giant, 209maior, 209quadricostatus, 209tenellus, 209Ecsenius sp., 161Eel, Spiny, 123Egeria, 203, 214densa, 203Eggs, 60, 61, 62, 63, 64, 65,73adhesive, 64fertilizing of, 47grid for protection of, 63laying of, 60, 61, 62, 63, 65scattered, 63Eichhornia, 213, 214azurea, 213crassipes, 213Eigenmannia virescens, 122Element, 234electric heating, 233Eleocharis, 204, 214minima, 204vivapara, 204Elephant-nose, Peters's, 122Elodea, 203, 214canadensis, 203densa, 203Dense, 203Empress, Red, 116Endosymbiosis, 169Enometoplus sp., 177Entacmaea quadricolor, 144,183Enteromorphs, 215Epalzeorhyncus, 88, 193kallopterus, 88siamensis 88, 195Ephippidae, 159, 178Epiplatys, 97annulatus, 98Equipment, checking of, 253Etroplus, 105maculatus, 119suratensis, 119Eutropiellus debauwi, 93Euxiphipopsnavarchus, 43, 137xanthometopon, 136Excretory system, 47Exophthalmus, 70Eye, 44, 48Eye-biter, Malawian, 115Farlowella sp., 92Favia, 184Favidae, 184Feather Foil, 209Feather, Parrot's, 205Feeding, 50, 60, 63, 67, 165,166, 174, 175, 257of fry, 56under-, 67Fern, 264, 265, 274Congo, 200floating, 196Javan, 210Sumatran, 210Fertilizer, 197liquid, 257solid, 257Fighting fish, Siamese, 43,120, 121File fish, 160Orange-spotted, 160Tassled, 160Filtration, 19, 68,200,218,238, 250bacterial, 238biological, 238, 246flow of, 244, 249mechanical, 168power of, 244in sea water, 249Filter, 19,57,66, 67,68, 173,174, 194, 235, 237, 238, 242,246, 247, 248, 249, 250, 258,259, 272box, 168,223, 239,242,243, 245, 248, 268, 272emergency foam, 248external, 238, 241, 243,248, 249external, with electricmotor, 241gutter, 243interior, 248interior fed by air, 240interior, with electric motor,240reverse-flow under-gravel,249submerged with electricmotor, 241under-gravel, 238, 239,240, 246, 249, 260, 262, 272,273284

wet/dry, 243, 245, 248Filtering media, 240, 241,246, 247, 248, 257, 258cleaning of, 249Fin, 42, 43, 48, 64, 67, 70adipose, 42, 43anal, 42, 64caudal, 42, 48dorsal, 42paired, 42pectoral, 42pelvic, 42unpaired, 42Fingerfish, 124Flag, Sweet, 202Food, 65, 67artificial, 50,51, 52,55,57,59automatic distributor of, 58,257distribution of, 56, 57, 174flakes, 51freeze-dried, 52frozen, 52of natural origin, 52planktonic, 55rations of, 50, 56Forcipiger flavissimus, 45, 135Formol, 69, 71Fox, Flying, 88Siamese, 88Foxface, 149Frontosa, 111Fry, 55,59, 60,61, 62, 63,64, 192feeding of, 56maturing of, 60Fundulus, 97Fungia sp., 184Fungidae, 184Gambusia affinis, 99Spotted, 99Garden pond, 33, 202, 213Gasteropelecidae, 80, 81Gasteropelecus sternicla, 81Gastropods, 36, 113, 165,166, 176, 177, 180, 186, 195,279Genicanthuscaudovittatus, 139lamarck, 139Geophagus brasiliensis, 105,111Redhump, 111steindachneri, 105, 111Gill, 45Glass, 221, 222Glassfish, 123Glass pane, 252, 257Glossadelphus zollingeri, 211Glyphidodontopscyaneus, 145hemicyaneus, 145Glue, silicone, 222Gluing, 224Gnathonemus petersii, 122Gobiidae, 124, 161, 176Goby, 161Catalina, 161fire, 161Goldfish, 86, 87Bubble-eye, 87Celestial, 87Japanese veiltail, 87Lionhead, 87Shubunkin, 87Telescope-eyed, 87varieties of, 86Gomphosus coerulus, 147Goniopora sp., 184Gonopodum, 99GoodeidButterfly, 103Red-tailed, 103Goodeidae, 99, 100, 103Gorgonia, 183, 185GouramiBlue, 121Dwarf, 121Giant, 120Honey, 120Kissing, 121Pearl, 121Sunset variety, 121Thick-lipped, 120Three-spot, 121Gramma, 158Loreto, 158Royal, 158Grammidae, 158, 176, 178Granule size, 240, 241, 248,249, 260GrassEel, 207Fish, 203Star, 204Gravel, 240, 246GrouperBlack, 130Marine beta, 158Red-spotted, 130White line, 130Growth, 49, 50, 51, 175, 191,196, 197, 198, 274Grunt, 154Gularis, Blue, 96Guppy, 100, 278feral, 100varieties of, 100, 101Gymnocorymbus ternetzi, 72,76Gyrinocheilidae, 92Gyrinocheilus, 192, 193aymonieri, 92, 195Gyrodactyliasis, 70Haemulidae, 154Halfbeak, Malayan, 103Halimeda tuna, 214Haloragaceae, 205Hamlet, 131Blue, 131Golden, 131Indigo, 131Shy, 131Hap, Deepwater, 105Haplochromis, 105, 114, 280ahli, 105annectens, 105boadzulu, 105compressiceps, 105electra, 105linni, 105Linn's, 105moorii, 105Hardness, 15, 16, 16, 16, 17,18, 22, 23, 30, 62, 195, 246,247, 251, 253, 254, 255, 257,259, 265carbonate, 16, 17, 18, 25Clark's degrees of, 16French degrees of, 16general, 17, 18, 25,251German degrees of, 16parts per million, 16Harpfish, 148Hasemania nana 77HatchetfishMarbled, 81Silver, 81Hawk, 178Longnose, 160Head, 44Head-and tail-light fish, 78Health, 277Healthy carrier, 66Heater-thermostat, 233, 234,235Heating, 233, 234, 235, 237,259, 273Helostoma temmincki, 121Helostomatidae 121Hemichromis, 105bimaculatus, 60, 105, 118Hemigrammusbleheri, 77caudovittatus, 77erythrozonus, 16, 77hyanuary, 77ocellifer, 78pulcher, 77rhodostomus, 77Hemirhamphidae, 100, 103Heniochusdiphreutes, 135intermedius, 135varius, 135Hermaphrodism, successive,61Hems severus, 78, 103, 105,108Heteractis, 182, 183aurora, 144crispa, 144magnifica, 144, 182Heteranthera, 204, 214, 278dubia, 204Yellow-leaved, 204zosterifolia, 204Hexacorals, 171, 182Hippocampus kuda, 42, 157,215Hippuhdaceae, 209Hippurus , 209, 214vulgaris, 209Hog, Coral, 148Hogfish, Spanish, 148Holacanthus ciliaris, 137Holidays of aquarist, 257Holocentridae, 128, 178Hottonia, 209, 214inflata, 208, 209HQI, 230Hush puppy, 157Hybrid, 73, 190Hydrocharitaceae, 207Hydrodynamics, 42, 43, 48Hydrometer, 25, 251Hydrozoa, 171HygroGiant, 204Willow leaf, 204Hygrophila, 199, 204, 214,279corymbosa, 204difformis, 204guianensis, 204salicifolia, 204Hyphessobrycon bentosi, 78callistus, 78erythrostigma, 78herbertaxelrodi, 78peruvianus, 78serpae, 78Hypnaceae, 211Hypoplectrusgemma, 131gummigutta, 131guttavarius, 131indigo, 131Hypostomus, 193plecostomus, 92HyssopSnowflake, 202Water, 202Ichthyophthirius, 70Ichtyophthyriasis, 69, 70, 71Idol, Moorish, 149Infusorian, 58, 192Invertebrates, 24, 26, 30, 33,38,69, 72, 162, 164, 166,167, 169, 170, 172, 173, 174,176, 177, 178, 192, 195, 226,227, 231, 238, 244, 249, 250,251, 264Iron, 21, 53, 196, 198, 251Jawfish, pearly, 160Julidochromis, 105, 280dickfeldi, 112marlieri, 112, 280ornatus, 112regani, 112transcriptus, 112JulieConvict, 112Dickfeld's, 112Marlier's, 112Masked, 112Ornate, 112Striped, 112Kennyi, 117Killie/Killifish, 36, 95, 96, 261Clown, 98Marbled, 96Steel-blue, 96Tanganyika pearl, 98Walker's, 96Knifefish, African, 122Clown, 122Green, 122Indian, 122Koi, 87Kribensis, 118Kryptopterus bicirrhis, 93, 279Kuhli, 88, 279Labeo, 37, 86, 279bicolor, 86frenatus, 86Labeotropheus, 105,116fuelleborni, 105, 116trewavasae, 105, 116Labridae, 61, 146, 178Labroides dimidiatus, 147Labyrinthidae, 120Lactoria cornuta, 155Lake Malawi, 114, 117Lake Tanganiyka, 111, 114Lake Victoria, 119Lampdischarge, 228halogen, 228HQI, 168incandescent, 228UV, 168, 251,258Lamprichthys tanganicanus,98, 280Lamprologus, 280Lamprologus, Lyretail, 112Lateral line, 42, 45, 46, 49Lates niloticus, 118Lava, 265Layering, 200Leaf fish, African, 123Lebiasinidae, 80, 81Lemna, 210, 214gibba, 210minor, 210Lemnaceae, 210Leporinus striatus, 80Striped, 80Leptosammia, 184pruvoti, 184LettuceWater, 211Sea, 215Lienardella fasciata, 148Light, 226loss of, 230Lighting, 197, 226,230, 232,233, 257hood, 227, 228, 230Limnophila, 205, 214aquatica, 205heterophylla, 205LionfishAntenna, 152Dwarf, 152Radiata, 152sting of, 152Volitan, 152Livebearer, 100, 279Live prey, 51, 53,55, 59"Live rock", 177, 194, 274Lo vulpinus, 149Loach, 88, 89Clown, 89Coolie, 88, 279Half-banded, 89Hora's, 89Horse-faced, 89Long-nosed, 89Orange-finned, 89Pakistani, 89Zebra, 89Lomaropsidaceae, 210Longevity, 49Loricariidae, 90, 92Lotus, 213Purple, 213LudwigAlternate leaf, 205Large-petaled, 205Rampant, 205Ludwigia, 205, 214, 278alternifolia, 205ascendens, 205brevipes, 205repens, 205Lumphead, Blue, 115Lusimakhos (False), 205Lutjanidae, 128, 178Lutjanuskasmira, 129sanguineus, 129sebae, 128Lyretail, Cape Lopez, 96Lysmataamboinensis, 186grabhami, 186Lythraceae, 206Lythrypnus dalli, 161Macrobrachium, 166, 181, 279lanchasteri, 181rosenbergii, 181Macropodus opercularis, 67, 21Maerl, 263, 281Magnesium, 15, 16, 17, 26,53, 196, 198Maintenance, 253of the bed, 254of the vegetation, 257Malachite green, 69, 71Malawi, Lake, 114Mandarin, Blue, 159Manganese, 21Marble, glass, 63Marine fishcohabitation between, 127for beginners, 127285

for experienced aquarists,127Mastacembelidae, 123Mastacembelus sp., 123Mbuna, 35, 36, 116Livingstone's, 115Slender, 117Medusa, 164, 171Meeki, 44Megalamphodusmegalopterus, 79Melanochromis, 105, 116, 280auratus, 116crabo, 117johnanni, 117Melanoides tuberculata, 180Melanotaenia boesemani, 94herbertaxelrodi, 94maccullochi, 94Melanotaeniidae, 94Mesonauta festivus, 107Methylene blue, 68, 69Metynnis, 80argenteus, 81Microgeophagus ramirezi,see Papiliochromis r.Micronutrients, 21, 29, 30Microsorium, 210, 214pteropus, 210Milfoil, 205Spiked, 205Water, 205Minnow, White cloudmountain, 88Mirror, 270Mochokidae, 93Moenkhausiasanctaefilomenae, 79Yellow-banded, 79Molly, 99Black, 99Black lyretail, 99Pointed-mouth, 99Sailfin, 99Short finned, 99Sphenops, 99Yucatan sailfin, 100Mollusks, 16, 28, 164, 165,166, 174, 176, 178, 186, 263,267bivalves, 169Molt, 165Monacanthidae, 160, 178Monocirrhus, 123Monodactylidae, 124Monodactylus argenteus, 124moorii, 114sebae, 124Mormyridae, 122Mosquito fish, 99Moss, 69, 191, 246, 248, 249,264, 265, 274Bogor's, 211Javan, 211,279Mouth, 44, 45MouthbrooderBurton's, 118Dwarf Egyptian, 119Mozambique, 118Nile, 118Mouth brooding, 61, 64, 280Mucus, 43MudskipperBlotched, 124Butterfly, 124Murena, 148Snowflake, 148Murenidae, 148, 178Murex, 186Muskrat root, 202Mussels, 51, 52, 53, 166,170, 174, 175, 176,275choppy made of, 174Myersi, Slimy, 89Myriophyllum, 64, 205, 214,278aquaticum, 205,spicatum, 205Myripristisjacobus, 128murjdan, 128Namecommon, 72of genus, 72of species, 72Nandldae, 123Nannacara anomala, 105, 111Nannobrycon eques, 81Nannostomus trifasciatus, 81Nasobrevirostris, 151lituratus, 151Nauplius, 56, 57, 58of brine shrimp, 55, 56, 57,58, 174Nemateleoths magnifica, 161Nematobrycon palmeri, 79Neolamprologus, 105, 280brevis, 113brichardi, 112leleupi, 105, 113multifasciatus, 70sexfasciatus, 105, 113tetracanthus, 105, 113tretocephalus, 105, 113Neothauma, 111, 113Nimbochromis linni, 115livingstonii, 115polystigma, 115venustus, 115Nemipteridae, 154Net, landing, 251,252, 273Nitrate, 19, 20, 21, 22, 26, 27,30, 47, 168, 170, 172, 178,192, 193, 198,251, 253,254,255Nitrite, 19,20,21,22,27,68,71,251,253,254, 257,259,275Nitrogen, 19, 20, 26, 27, 29,47, 172, 192, 194, 198, 238,240, 243, 249, 250, 259, 260,262, 263, 274Nomaphila corymbosa, 204Nomenclature, English andLatin, 72Nostril, 45Notho, Gunther's, 98Nothobranchius, 97guentheri, 98Notopterldae, 122Notopteruschitala, 122notopterus, 122Nympheaea, 213, 214, 279lotus, 213rubra, 213Octocorals, 171, 185Ocyurus chrysurus, 129Odonus niger, 154Onagraceae, 205Oodinium, 70Operculum, 42, 45, 67, 70Ophiuroid, 177Opistognathidae, 160Opistognathus aurifrons, 160Oreochromis, 105mossambicus, 118niloticus, 118Organic substance, 253Origin of fish, 276Oscar, 110Osmoser, 17Ostracioncublcus, 155meleagris, 155Ostraciontidae, 155, 178Otocinclus, 193vittatus, 92Oxycirrhites typus, 160Oxygen, 12, 13, 16, 19, 20, 21,21, 22, 45, 46, 47, 52, 65, 66,70,71, 165, 170, 172, 175,190, 192, 196,235,238,240,246, 249, 251, 254, 262, 275Oxygenation, 235Oxymonacanthus longirostns,160Oyster, 59Shell, 246, 247, 250, 263Pagurid, 176, 177Palaemonidae, 181Panaque, 193Panchax, Blue, 98Lyretail, 96Striped, 98Pangasiidae, 93Pangasius sutchi, 93Pantodon buchholzi, 122Pantodontidae, 122Papiliochromis, 105ramirezi, 105, 110Paracanthurus hepatus, 151Paracheirodon innesi, 79Paradise fish, 121Parapetenia salvini, seeCichlasoma s.Parasite, 43, 46, 69Parazoanthus sp., 183Parkoriaceae, 210Peacock, Nyassa, 114Pearl fishArgentinian, 97Black-finned, 97Peat, 14, 15, 16, 95, 246,247, 250, 258Peduncule, caudal, 42Pelvicachromis pulcher, 105,118Pencilfish, 80Brown-tailed, 81Hockey-stick, 81Three-lined, 81Penguin, Boehlke's. 80Perch, Nile. 118Periopthalmus, 124barbatus, 124papilio, 124Perlon, 246, 247, 248Petitella georgiae, 77pH, 13, 14, 15, 16, 17, 18,20,21,22,23, 26,36, 37,62,68,71, 75, 114, 168, 173, 196,197, 246, 247, 251, 253, 254,255, 257, 259, 263Pheasant, Golden, 98Phenacogrammus interruptus,76Pheophyceae, 194Phosphor, 53, 198Photosynthesis, 13, 21, 169,192, 196, 226, 228,254Physa, 166, 180Physa sp.. 180Physobrachia douglasi, 144Phytoplankton. 170, 194Pimelodidae, 92, 93Pimelodus,Angelicus, 93pictus, 93Piranha, 80. 81Red-bellied, 81Pistia, 211, 214stratoites, 211Placidochromis electra, 116Plankton, 15, 19, 28,29, 52,55, 164, 165, 166, 174, 176Planorbis, 166, 180Planorbis sp., 180Plants, 13, 15, 19, 21, 23, 32,33, 34, 35, 37, 38, 44, 50, 58,62, 63, 64,66, 190, 191, 192,193, 196, 197, 199,200,273,274artificial, 66, 192Leiden's, 212natural, 192root of, 266Planting pincers, 252Platax pinnatus, 159Platy, 43, 101, 103, 278Variegated, 101, 102varieties of, 101Platygira, 184Pleco, 92Plectorhynchidae, 129, 178Plectorhynchuschaetodontoides, 129gaterinus, 129orientalis, 129Plerogyra sp., 184Plesiopidae, 158, 178Plexiglas, 218Plotosidae, 155Plotosus lineatus, 155Plume, branchial, 175Poecilia, crosses andvarieties of, 103latipinna, 99reticulata, 100sphenops, 99velifera, 100Poeciliidae, 55, 58, 61, 65,99, 100, 103, 125, 192, 193,278Pollution, 178Polycentropsis abbreviata,123Polyp, 170Polypordiaceae, 210Polystigma, 115Elephant-nose, 115Polystyrene, 267, 269, 271,277, 280box, 277Polyurethane, 267, 268, 269,271, 280Pomacanthidae, 44, 136, 141,178Pomacanthusannularis, 137chrysurus, 137imperator, 138maculosus, 138paw, 138semicirculatus, 138Pomacentridae, 142, 146, 178Pond weed, Canadian, 203Pontederiaceae, 204, 213Porcupine, Common 156Pork fish, 154Poritidae, 184Posidonia oceanica, 215Poster, 270Potability, 17, 22Potassium, 26, 198Pre-filtration, 247, 247Premnas biaculeatus, 143Prevention. 67, 68Primulaceae, 209Prionobrama filigera, 79Pristella maxillaris, 80Procamburus ciarkii, 181Protein, 51, 54Protein skimmer, 68, 168,242, 250, 258, 273, 276Protomelasannectens, 116similis, 116Pseudanthias squamipinnis,130Pseudobalistes fuscus, 154Pseudochromis, 158, 176, 178diadema, 158Pseudocrenilabrus multicolor,119Pseudotropheus, 105, 116, 120elongatus, 117lombardoi, 117socolofi, 117tropheops, 117, 280zebra, 117Pteroisantennata, 152radiata, 152sphex, 152volitans, 42, 152Pterophyllum, 105altum, 108scalare, 16, 108PufferFigure-eight, 125Meleagris, 157Peacock, 156Reticulated, 125Round-spotted, 125Stars and stripes, 157Valentini, 156Yellow, 157Pump, 26, 168, 241, 242,245, 249air, 235, 236, 237, 252electric injection, 250power of, 245Puntiusconchonius, 82lateristriga, 83nigrofasciatus, 82PVC, 246, 248, 250Pygoplites diacanthus, 139Rabbitfish, 149Race, 73Radianthus, 182, 183gelam, 144malu, 144paumotensis, 144ritteri, 144simplex, 144RainbowfishBoeseman's, 94Celebes, 94Dwarf Australian, 94Lake Tebera, 94Madagascar, 94McCulloch's, 94Ramirezi, 110Rasbora, 82, 85, 279borapetensis, 85elegans, 85Elegant, 85Harlequin, 85heteromorpha, 85Magnificent, 85Red-tailed, 85Scissortail, 85trilineata, 85Red soldier fish, 128Reef, coral, 167Remounting an aquarium,259Reproduction, 48, 49, 50, 60,61, 62, 63, 65, 175, 196, 199,200, 247Reproductive organ, 47Resin, 269epoxy, 269polyester, 218Respiration, 67286

Fthamphichthyidae, 122Rhinecanthusaculeatus, 153assasi, 153rectangulus, 153verrucosus, 153Rhodophyceae, 194fl/cc/a, 58, 211,214Floating, 211flufans, 211Rivulus, 97Cuban, 97cylindraceus, 97Rock, 168, 246, 260, 264, 265calcareous, 247volcanic, 246Roloffia, 97geryi, 98occidentalis, 98Rotala, 206, 214Giant red, 206macrandaRound leaf, 206rotundifolia, 206Rotifer, 56, 58, 174Rush, spiked, 204Sabellastarte sp., 164, 185Sand, 219, 240, 246, 260coarse, 246, 260, 261coralline, 246, 281dune, 263fine, 260, 261live, 263Loire, 261quartz, 261Sagittaria, 200, 206, 214graminea, 206sagittifolia, 206, 214Salinity, 24, 25, 26, 29, 37,38, 57, 124, 195,255Salt, 173, 193kitchen, 68mineral, 51, 174, 196, 197,198, 255Salt marsh, 56Salvinia, 211, 214auriculata, 211minima, 211Salviniaceae, 211Saprolegnia, 69, 70Sarcophyton, 174, 175, 185glaucum, 185trocheliophorum, 185Saururaceae, 212Saururus, 212, 214cernuus, 212Scalare, 35, 44, 64, 73, 90,108, 109, 192Common, 108Scalarias, 244Scale, 43, 67ScatSpotted, 125Tiger, 125Scatophagidae, 125Scatophagus argus, 125rubifrons, 125Schilbidae, 93Sciaenochromis ahli, 115Scleractinaria, 168, 170, 171,175, 177, 184Scorpenidae, 152, 178Scrofulariaceae, 202, 205Sea urchin, 165, 177Seahorse, 157Golden, 157Sediment, 166, 168, 234,238, 240, 249,260,261,262,263,264, 266,269,271,272,273, 274, 275Sergeant-major, 145Serranidae, 130, 178Serrasalmidae, 80, 81Serrasalmus nattered, 81Severum, 78, 103, 105, 108Shale, 265SharkBala, 88Rainbow, 86Red-finned, 86Red-tailed black, 86Siamese, 93Tricolor, 88Shell-dweller, Dwarf, 113Shellfish, 53Shingle, 265Shrimp, 38, 52, 54, 55, 165,166, 174, 175, 176, 178, 181,186,279Barber, 186Cleaner, 186River, 54Siganidae, 149Siganus, 149Siluridae, 93Siluriformes, 90Siphoning, 220, 254, 255,256, 257Slate, 265SnailApple, 180Malaysian, 166, 180Snapper, 128Blood red, 129Blue and gold longfin, 154Eight-stripe, 129Panther, 130Red emperor, 128Yellowtail, 129Sodium, 17, 24, 26Sorubim lima, 92Sulfur, 26Spathiphyllum, 212wallisii, 212Spathy, 212Species, distribution andclassification of, 72Specific gravity, 24, 25, 26,30,31, 34, 57, 168, 246,251,253, 254, 255, 257, 259, 273Sphaeramianematoptera, 159orbicularis, 159Spilotum, 107Sponge, 164, 167, 169, 170,177, 178, 182, 183Squirrel fish, 128Starfish, 165, 177Steatocranus, 105casuarius, 119Stenopus hispidus, 186Stichodactyla, 183gigantea, 144haddoni, 144mertensii, 144, 183Stoichactus, 183giganteum, 144kenti, 144Stoichactus sp., 144Sturisoma rostratum, 262Substrate, 168,262Support, 220Surgeonfish, 150Sweetlips, 129Black-spotted, 129Spotted, 129Zebra, 129Swim bladder, 47, 154Swordtail, 73,101, 103Montezuma, 102Red veiltail, 102varieties of, 102Symphorichthys spilurus, 154Symphysodon, 105aequifasciatus, 109discus discus, 109Synchiropus splendidus, 159Syngnathidae, 157, 178Synnema triflorum, 204Synodontis,Even-spotted, 93nigriventris, 93petricola, 93Tang, 150Achilles, 151Clown, 150Hippo, 151Powder blue, 150Powder brown, 150Sailfin, 151Sohal, 151Yellow, 151Tanganyika, Lake, 111Tanichthys albonubes, 88Tankfreshwater CentralAmerican, 278hospital, 221lid Of, 220, 227, 228Telmat, Striped, 113Telmatherina ladigesi, 94Telmatherinidae, 94Telmatochromis, 105bifrenatus, 113brichardi, 113Temperature, 12, 13, 22, 24,25, 26, 32, 33, 34, 35, 36, 37,57, 60,66, 67, 68, 69,71,178, 220, 222, 233, 234, 235,253, 254, 257, 259, 273, 277Terracotta, 268TetraBlack, 76Black neon, 78Black phantom, 79Black widow, 76Bleeding heart, 78Blind cave, 46, 76Buenos Aires, 77Callistus, 78Cardinal, 76Congo, 76Emperor, 79Garnet, 77Glowlight, 77Hornet, 119January, 77Jewel, 78Lemon, 78Loreto, 78Neon, 79Red-nose, 77Rummy-nose, 77Rummy-nose, False, 77Rosy, 78Serpae, 78Silver-tipped, 77Zaire, 76Tetracanthus, 117Tetraodon, 125, 180biocellatus, 123fluviatilis, 125palembangensis, 125reticulatus, 125Tetraodontidae, 125Thalassoma lunare, 148Thayeria boehlkei, 80Thermometer, 234, 251external liquid crystal, 251mercury, 251Thermostat, 233, 235, 273Thorichthys meeki, 105, 107Tilapia, 105,118, 119buttikoferi, 105, 119mariae, 105, 119Tiger, 119Timerelectric, 252, 257electric programmable, 233Toxicity, 20Toxotes jaculator, 125Toxotidae, 125Trace elements, 255Transport, 276Trichogasterleeri, 121trichopterus, 121Tridacna sp., 186Trigger, 153, 160Blue, 154Blue line, 154Blue throat, 154Clown, 153Picasso, 153Royal, 153Undulated, 153Tropheops, 117Tropheus, 105duboisi, 114moorii, 114Tropical fishes, harvesting of,74Tube, fluorescent, 196, 227,228, 229, 230,231, 232,233Tubipora, 267Turbidity, 19, 22, 28,45Uaru amphiacanthoides, 111UCA, 39Udotea, 215petiolata, 214Udoteaceae, 214Ulva, 215Ulvaceae, 215Unicom fishLongnose, 151Smooth-headed, 151UV sterilization, 250, 251,273, 276Vacuum cleaner, 252Vallisneria, 200,207, 214,266, 279asiatica, 207giant, 207gigantea, 207spiraled, 207spiralis, 207Vegetative multiplication, 199Venustus, 115Vertebrate, 46Vesicularia, 211, 214dubyana, 211Victoria, Lake, 119Vitamin, 21, 30, 50, 51, 52,53,70, 174, 198Vitellin sack, 58, 61Water, analysis of, 253brackish, 124changing, 254, 257osmosis, 17, 18quality of, 70Water hyacinth, 213Azure, 213Water sprite, 203Water spruce, 209Water wisteria, 204Woodpeat-bog, 266petrified, 265Worm, 50, 52, 54, 55, 56, 70,164, 175, 178, 185Mud-, 54parasite, 70Tubifex, 54, 58WrasseBirdmouth, 147Cleaner, 147Coris clown, 146Formosa, 146Harlequin tusk, 148Lunar, 148Red coris, 147Xanthichthys auromarginatus,154Xenomystus nigri, 122Xenotoca eiseni, 103, 276Xiphophorus, 103helleri, 72, 101, 102, 278maculatus, 101montezumae, 102variatus, 43, 102X-ray fish, 90Zanclidae, 149Zancluscanescens, 149cornutus, 149Zebrasomaflavescens, 151veliferum, 151Zoantharia, 183Zooxanthellae, 38, 168, 169,171, 174, 182, 183, 184, 230,231287

All the photographs are the property of Yves LANCEAU and Herve CHAUMETON/agence Nature, with the exceptionof the following:Aquapress: p. 167 - Berthoule/Nature : p. 12 ; p. 15; p. 25 (t); p. 30 (t); p. 51 (1); p. 52; p. 53 (t); p. 54 (b); p. 5~(t); p. 58 (1); p. 168 (t); p. 173 (t); p. 222; p. 223; p. 230; p. 234; p. 235 (t); p. 236; p. 236/237 ; p. 238; p. 240; p. 241:p. 242 (1) ; p. 247 (b) ; p. 248 (t); p. 250; p. 251; p. 252; p; 254; p. 257; p. 271; p. 272; p. 273; p. 277 - Biehler/Aquapress: p. 25 (b) - Bretenstein: p. 55 (b); p. 56 (b); p. 169 (b) - Chambfort: p. 24; p. 221 (t) - Corel: p. 43 (ml);p. 68; p. 128 (mr-bl); p. 129 (tr); p. 131; p. 132 ft) ; p. 134 (b) ; p. 135 (tl); p. 137 (t-b); p. 143 (tr) ; p. 145 (mr) ; p.146 (ml); p. 148 (tr); p. 152 (tr); p. 153 (br); p. 154 (bl); p. 156 (bl); p. 161 (t); p. 163 (b) ; p. 164 (tr); p. 165 (tr); p.171 (t); p. 176 (t-c); p. 182 (c); p. 231 ; p. 244 ; p. 258 - Etcheverry: p. 181 (c) - Francour/Aquapress: p. 28 -Genetiaux/Aquapress: p. 185 (mr) - Guerrier/Nature: p. 213 (ml) - Heather Angel: p. 81 (tr) -Houtmann/Aquapress: 182 (b) - JM/ Bour/UW/Cameraman photographer: p. 267 - Lamaison/Nature: p. 33(t); p. 203 (br); p. 206 (ml); p. 210 (ml) - La Tourette/Nature: p. 133 (tl); p. 138 (mb-bl) - Londiveau/Aquapress:p. 35 (r) - Louisy: p. 61 (t) ; p. 76 (c); p. 87 (tr-b); p. 94 (br); p. 104 (c); p. 107 (tr); p. 108 (ml); p. 112 (b); p. 113(c-br); p. 130 (bl); p. 130/131 (b); p. 135 (tr); p. 136 (tl); p. 137 (mr); p. 140 (br) ; p. 144; p. 145 (tr-bl); p. 146 (br);p. 150 (c) ; p. 164 (tl); p. 165 (tl-b); p. 177 (tl); p. 180 (t); p. 187 (tr); p. 208/209; p. 215 (tr) - Maitre-Allain : p. 23(b); p. 59 (0; p. 102 ft); p. 103 (bl); p. 109 (tr); p. 148 (b); p. 155 (tr); p. 164 (b); p. 174 (b); p. 175 ; p. 183 (c); 185(ml); p. 190; p. 194 (t); p. 200: p. 220; p. 229; p. 248 (b); p. 249; p. 259; p. 261; p. 263 ft) ; p. 274; p. 278; p. 279; p.280; p. 281 - Pecolatto/Nature: p. 94 (bl) - Piednoir/Aquapress: p.4; p. 5; p. 8; p. 9; p. 14; p. 20; p. 21; p. 29; p.30; p. 31; p. 32; p. 33 (b); p. 34; p. 35 (1); p. 36; p. 37 ; p. 38; p. 39 ft) Aquarium de Tours; p. 39 (b); p. 40; p. 41;p. 42 (1) ; p. 43 (mr); p. 44 (b); p. 47; p. 48/49; p. 50 : p. 51 ft - c); p. 52 (tl); p. 53 (b); p. 54 ft); p. 56/57; p. 58 (r);p. 59 (b); p. 60 ; p. 61 (b); p. 62; p. 63; p. 64; p. 65; p. 70: p. 71; p. 72 (b); p. 73; p. 74; p. 75 (b); p. 77 (tl); p. 77(mr); p. 78 (mr); p. 80/81; p. 81 (ml); p. 82 (t); p. 87 (tl-c): p. 89 (tr-ml-bl); p. 91 (ml); p. 92 (tr); p. 93 (mbl); p. 96;p. 97; p. 98 (tr-ml-bl); p. 100 (mtr-b) ; p. 101 (c); p. 102 (ml-bl); p. 103 (t-c); p. 104 (b); p. 105 (tl-bm); p. 106 (t-bl);p. 106/107 (b); p. 107 (tl); p. Ill (mr); p. 112 (t-mt); pll2/113 (0 ; p. 113 (tr-mbl); p. 114 (ml); p. 114/115; p. 115(b); p. 116 (ml); p. 116/117; p. 117 (mtr-mbl-bl); p. 118 (bl): p. 118/119: p. 122/123; p. 133 (tr-bl) ; p. 139 (mbr); p.138 (mtl); p. 142 (tr); p. 147 (b); p. 148 (ml); p. 149 (c); p. 150 (br); p. 151 (mr); p. 153 (bl); p. 154 ft); p. 157 (b);p. 158 (t); p 160 (t-bl); p. 161 (c-b); p. 162/163; p. 166 (1); p. 168 (b); p. 169 ft); p. 170; p. 173 (b); p. 174 ft); p. 176(b); p. 177 (tr-b); p. 179; p. 180 (c-b); p. 181 (t-b); p. 182 ft); p. 183 (t-b); p. 184 (t-b); p. 185 ft-ml-br); p. 186 (t-b);p. 187 (tl-c-b); p. 188/189; p. 189 (t-b); p. 191 (bl): p. 192 (b); p. 193; p. 194 (b); p. 197; p. 198; p. 199 ft); p. 201(b); p. 203 (bl); p. 204 (t) ; p. 204/205; p. 205; p. 207 (tr-b); p. 209 (tr-ml-br); p. 210 (br); p. 210/211; p. 211 ft-br);p. 213 (tl-mr-b) ; p. 214; p. 214/215; p. 215 (c) ; p. 216/217: p. 217 (t-b); p. 218; p. 219; p. 221 (b); p. 226/227; p.228; p. 233 ; p. 235 (b); p. 242 (r); p. 243; p. 245; p. 246; p. 247 ft); P- 253; p. 255; p. 260; p. 262; p. 263 (b); p. 264;p. 264/265; p. 265 ; p. 266; p. 266/267; p. 268; p. 269: p. 270; p. 275; p. 276; p. 281 (t) - Prevot/Nature: p. 120 (ml)- Quinn/Nature : p. 172. - Roulland/Aquapress: p. 10/11; p. 23 (t) - Sauer/Nature : p. 56 ft) - Tramasset &Etcheverry: p. 166 (r).288

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