Introduction

Ornamental fish is an important sector of the aquaculture industry. More than 120 countries are involved in the ornamental fish trade. It is interesting to note that there are more than 1800 species of ornamental fishes in the market of which more than 1000 varieties are from freshwater region. India contributes about 1% of total ornamental fish trade. Tamil Nadu, Kerala and West Bengal are the major states involved in ornamental fish farming. Ornamental fish keeping is raising day-by-day because it provides a great opportunity for entrepreneurship development and income generation. There are a number of promotional schemes from various government agencies which would boost up aspiring entrepreneur. The technology is quite simple and easy to take up and attain success. Barbs, loaches, danio, freshwater sharks, gourami, glass fish, molly, goldfish, platy, sword tail, oscar, discus, siamese fighter fish, severum, angelfish and tetra are the major ornamental fishes which are exported from India. However, diversification of species is the need of the hour.

Although wide varieties of ornamental fishes are available, species which have attractive looks with export potential must be selected for culture. Panchax are small, attractive, colorful and hardy fishes which have good export value. They can also be easily reared in the tanks and can be compatible with other tank-mates. A pair of panchax fish costs about US$ 2.16 (162 INR). So they are suitable for the ornamental fish trade in the local Indian and international markets.

Dwarf panchax

Dwarf panchax comes under killifishes which belongs to the family Aplocheilidae. They are widely distributed in the world except in Australia and Antarctica. They are mainly found in shallow tropical and subtropical waters. There are many killifish species for fish keeping purpose.

Dwarf panchax, Aplocheilus parvus is one of the ornamental fish species among the Aplocheilidae family. This species was first identified and described by Sundara Raj in 1916. The word Aplocheilus is derived from Greek, ‘aplo’ means ‘simple and plain’ and ‘cheilos’ means ‘lip’. The word ‘parvus’ is derived from Latin, meaning ‘little and cheap’. The native of this species is Tamil Nadu, South Eastern India and Sri Lanka. It is an euryhaline fish and found mostly in lowland, often coastal habitats containing still or slow-moving brackish or fresh water. It prefers habitats with surface vegetation or overhanging cover. It is commonly found in mangroves, swamps and paddy fields.

Table 1. Important ornamental species of panchax

Killifishes vary in their appearance with bright color and vivid patterns. Dwarf panchax grows up to 6 inch in length. Head is flat at the top. Mouth is present at the tip of the snout (ie. Terminal mouth). They have round scale and no barbels. They have elongated, slender and pike shaped body with round fins. They are good swimmers. Dorsal fin is present at the back half of the body. Males will be larger, more colorful and brighter and their anal fin is more pointed than that of female. Different color varieties are now present all over the world. The Indian varieties are yellowish in color and some red dots and small patches are present around the lateral line region. Sri Lankan varieties are silvery with yellow color body and the fins are multi-colored except pectoral fin which is silvery in color.

Tank set up

Though they swim at all levels of water in the tank, they mostly occupy the surface water. 20 gallon tank is suitable for a pair of panchax fish. They are good jumpers and hence the tank should be covered with hood. The bottom of the tank is covered with peat moss. Floating plants and tall plants can be provided for the fishes to hide in it. Other hiding places like rock caves, flower pots can also be provided in the tank.

Water Quality Management

Water exchange of 10% per week is recommended and if water quality is poor, 100% water exchange must be done. Optimum levels of other water quality parameters to be maintained in the tanks are given in table 2.

Table 2. Water quality parameters

Tank community

They are peaceful and can grow well in community tank, but sometimes male become aggressive towards other males of its own species. For beginners to rear panchax fish, it is advised to start with a pair of panchax fish in a tank. They can be compatible with other small and peaceful fishes such as tetra, danios, gobies, etc.

Feeding

They are carnivores in nature. In wild environment, they eat small crustaceans, insect larvae and worms. In sometimes, they eat algae. In aquarium, they can be acclimatized to take artificial feed and must be supplied with live feeds frequently. Brine shrimp (Artemia), daphnia, mosquito larvae, tubifex worms, fruit flies, beef heart, paste foods, dry foods and frozen live feeds can be included in their diet.

Breeding

Panchax are egg layers and batch spawners. Males will be more brighter than females. They prefer darkness for breeding and hence the breeding tank has to be kept covered in order to avoid bright light. The tank is sufficiently provided with fine leaved plants or sometimes artificial surfaces like ‘spawning mop’ can also be used for egg attachment site. Spawning mop is prepared from nylon yarns and they are cut into pieces of 6 inch length and they are tied together in the middle. A small cork is attached at the center, making it to float in the tank. During breeding males become aggressive toward the other males of its own species, so it is advised to provide one male and two females in a breeding tank. They lay about 10 to 12 eggs in one day and repeat the same on the next day and repeat it until they produce up to 150 to 300 eggs. The eggs are attached to the plants or spawning mop. After fertilization, the eggs attached to the plants or spawning mop are transferred to incubation tank for a period of about 12 to 16 days. After hatching, the fry utilize the yolk sac and start external feeding. Newly hatched larvae can be fed with newly hatched artemia nauplii, infusoria and micro-worms.

Fish diseases

Panchax fishes are hardy fishes and hence disease is not a problem in well-maintained tanks. If water quality of the tank is not maintained, velvet and other bacterial diseases may occur.

Velvet disease is caused by Oodinium sp. Fishes which are affected by this will have a cover or fine gold to gray film on the body and yellow to light brown dust like structures (velvet) present on the body. This disease can be treated by raising the temperature to 31 to 34ºC. Chemicals such as copper at 0.2 ppm or the antibiotic acriflavine (0.2%) at 1 ml/l and common salt at 2 g/l can be used to treat this disease.

Dropsy is caused by the bacteria, Aeromonas hydrophila causing bloating of the body and protruding scales. It is a bacterial infection of the kidneys, causing fluid accumulation or renal failure. It can be treated with antibiotics such as Chloromycetin (chloramphenicol) and tetracycline at the rate of 10 mg/l of water.

Tail or fin rot is caused by the bacteria, Aeromonas hydrophila and Pseudomonas fluorescens. Its symptoms include disintegrating fins that may be reduced to stumps, exposed fin rays, blood on edges of fins, reddened areas at base of fins, skin ulcers with gray or red margins, cloudy eyes. It can be treated using chloromycetin (chloramphenicol) and tetracycline at the rate of 10 mg/l of water.

Besides knowing these diseases, it is advised to know other bacterial, fungal and parasitic diseases and their treatments for the effective management. Even the decorative plants, substrate gravels may harbor disease causing organisms. So they should be cleaned and disinfected properly before adding them into the tank. New fishes should be always quarantined before releasing them into the aquarium. Diseases can be prevented by proper maintenance of water quality parameters, proper disinfection of gravels, stones, aquarium plants and fishes to prevent the invasion of disease causing organisms and by using the quality feeds.

Conclusion

The global aquarium fish trade including accessories and feed was estimated about US$ 18 – 20 billion in 2017, in which the contribution of India was 0.61% by quantity and 12.42% by value (US$). Several new ornamental fishes are available in the wild with different colors, patterns and strains. They can attract more hobbyists throughout the world and hence can be included in the ornamental trade. Introduction of new species like dwarf panchax, blue panchax, golden panchax and other killifishes, can increase the share of India in the ornamental fish export market.

Author:

Dr. C. Judith Betsy, M.B.A., M.F.Sc., Ph.D.,
Assistant Professor,
Department of Aquaculture,
Fisheries College and Research Institute,
Tamil Nadu Fisheries University,
Tuticorin- 628 008