Tetras are a fabulous family of tropical fish, arguably the most kept species of tropical fish in the aquarium hobby. They are generally very hardy and come in a variety of colours, from the somewhat drab Black Widow Tetra to the iridescent Cardinal Tetra. They are renowned for having a peaceful nature except for a few, such as the Bucktooth Tetra, making them a must-have addition to any community setup.
Below is a list of 132 different types of Tetra (with photos) found in the fishkeeping hobby, both rare and common.
Tetra is the well-known name of many small freshwater characiforms belonging to the biological family Characidae and its former subfamilies Lebiasinidae and Alestidae. There are currently over 100 tetra species divided up between the three families. Characidae can be recognised from other fish by their small adipose fin between the dorsal fin and tail. This adipose fin factors the fourth unpaired fin on these fish. Even though this adipose fin is generally considered the distinguishing feature, some Tetras, such as the Emperor Tetra, lack this feature.
Many of these fish have several bones that join the swim bladder and inner ear, enhancing these colourful fishes hearing. A majority of these fish are also brightly coloured and easy to take care of in captivity. Consequently, they are prevalent in home aquariums.
Tetras generally have compressed bodies and can be typically identified by their fins. They commonly possess a tall dorsal fin and a homocercal caudal fin distinguished by a short connection to the fish's body. Additionally, Tetras have a long anal fin extending from a posterior of the dorsal fin and ending on the ventral caudal peduncle. These fish also have a small, fleshy adipose fin found between the caudal and dorsal fins.
Species such as the Cardinal Tetra and Neon Tetra are among the most popular of all freshwater fish, adding a touch of social interaction and brilliance to the community aquarium. Tetras can vary in size from 4 cm to 15 cm, although most Tetras available in the hobby are smaller. Providing you take proper Care of your Tetra Fish, they can live for 5 to 10 years.
Natural habitat
Tetras are endemic to South and Central America and Africa, with a considerable majority coming from the Amazon Basin, except for the blind cave tetra, which was discovered in a cave system in Mexico.
Tetras live in a diversity of different regions. Some live across broad areas, while others live in a single river system. Each species of Tetra has its own specific distribution and range, though some species do overlay with the populations of others.
Many live in regions with submerged vegetation and shaded areas.
Behaviour
Most Tetras are colourful, calm, relatively peaceful and least aggressive and will get along well with similarly sized community fish. However, there are a few exceptions. Serpae Tetras, for example, can sometimes be a bit nippy, primarily when housed in insufficient numbers. Like the Buenos Aires Tetra, other Tetra species can get quite big and can be very active, which may intimidate more timid or smaller fish.
In the aquarium
Most Tetras are found in soft, acidic water in the wild; however, most aquarium species sold today are raised commercially in water that frequently has a higher pH and alkalinity than their natural environments. For most Tetras, the temperatures should be between 75 degrees Fahrenheit to 80 degrees Fahrenheit; the pH needs to be somewhere between 6.8 and 7.8 and the alkalinity between 6.8 and 7.8.
If you keep aquariums in rooms below 75 degrees Fahrenheit, it is advisable to use an aquarium Heater to maintain the correct temperature. Exceptions such as the Buenos Aires Tetra thrive in cooler water. Maintaining good filtration, having a nice flow of current and performing regular water changes is a must and make sure you remember to use a de-chlorinator if using tap water.
You can keep most Tetras in 35 to 90 Litre aquariums, but larger tanks are more accessible to take care of and provides them with more room to swim. Tetras fare better if kept in schools of 6 or more individuals; they will be less stressed and show their best colours.
If you have a well-decorated aquarium with a dark substrate, you will notice that you will accentuate your Tetra's colours. Ensure you have a secure fitted lid on your aquarium to prevent them from jumping out, which they will do if they feel threatened or scared.
The best tank mates for Tetras include other Tetra species, Danios, Rasboras, appropriately sized Rainbowfish, smaller peaceful Barbs and Livebearers.
Feeding
Most Tetras are omnivores and will thrive on high quality dried foods such as flakes, granules, wafers and pellets. You can also treat them with frozen and live foods on occasion unless you intend on spawning them, then feeding them with live and frozen foods often will help to induce spawning.
For the most beneficial results, rotate their diet daily and only feed them what they are able to consume in under 2 minutes, once or twice a day.
Breeding
In the wild, Tetras breed in the rainy season when the weather is wet with consistent rainfall. Still, when they adapt to an aquarium, they can multiply throughout the year due to controlled temperature and moisture conditions.
Some species of female Tetras become active for reproduction from the age of 9-12 months. But in some more extensive species, the functional period of breeding starts between 1.5 to 2 years.
If you would like to succeed in breeding Tetras, you should keep male and female Tetras in the same tank but separately using a partition for around 2 or 3 weeks where they can see their partners and prepare for future mating and parenthood.
It is simple to differentiate between male and female Tetras by their physical appearance. Males are usually slimmer and more colourful than females, whereas females are plumper and rounder due to carrying eggs.
When Tetras are ready to spawn, you must prepare another tank with a peat filter, established water and live plants. You will then need to add the female in the breeding tank a night before breeding and then add the male after.
Once you have added the male, it is essential that you watch the males behaviour because males can often show aggression by attacking females. You must remove the female and place her back into her section in the tank in such a situation. This will help the male in controlling his aggression and accept his partner next time.
You can place two or three females in the tank so that the male Tetra does not have to focus on one female. The best environment for breeding is one with little light and little visibility.
When the male Tetra fertilises the eggs, you must remove him from the tank immediately; this will stop the male from going after the pregnant female or the eggs.
The eggs usually hatch within 24 hours. The fry is tiny in size, so you should feed them something that they can ingest without difficulty. Infusoria is the best option and can be offered to them for the first few days. Once they develop a bit, they can be fed baby brine shrimp as well as commercial fry products to provide the necessary nutrients required.
