Tetra is a general name for tropical freshwater fish of the Characidae family.

They are popular because they are peaceful species that can live with many other types of aquarium features. Aquarium enthusiasts also love them because they are easy to maintain, particularly the ember tetra. They come in many bright colors, like yellow, cardinal, and bright greens and blues.

Five Tetra Facts

1. Tetras are among the world’s most popular aquarium fish.

2. Rummy-nose tetras love to shoal.

3. Tetras tend to act livelier when they are in bigger groups.

4. The ember tetra, discovered in 1987, was named after explorer Heiko Bleher’s mother.

5. Glow tetras, also called GloFish tetras, are genetically modified and can reach six inches long.

Tetra Classification and Scientific Name

All tetras are members of the Chcaraciformes order and the Characidae family. The scientific name of the neon tetra, probably the best known of these aquarium fish, is Paracheirodon innesi. Scientific names of some of the other tetras are yellow tetra, Hyphessobrycon bifasciatus; rummy-nose tetra, Hemigrammus rhodostomus; cardinal tetra, Paracheirodon axelrodi; ember tetra, Hyphessobrycon amandae; and glow tetra, Hemigrammus erythrozonus.

Tetra Species

More than 150 species of fish considered tetras live worldwide. Although there are many different species, less than 20 are commonly found in aquariums worldwide. Most pet stores sell neon tetras at a low price as they are plentiful. Other popular tetra species among hobbyist fishkeepers include black, cardinal, rainbow, blue, flame, rummy-nose, emperor, and bloodfin tetras. The most popular tetras also have a low price in pet stores, making them affordable.

Tetra Appearance

Tetras are small fish, generally ranging in length from one to four inches. The one exception is the genetically engineered glow tetra, which can grow up to six inches in size. Tetras have a small adipose fin between their dorsal and caudal fins, distinguishing them from other fish. You’ll find a few differences between male and female tetras. Males are usually thinner, while females are more rounded and tend to be larger. Colors are varied, ranging from silver and yellow to deep black.

Tetra Distribution, Population, and Habitat

Tetras are found around the world, although they are concentrated in the previously mentioned areas. They are primarily found in the freshwater rivers and lakes of the Amazon Basin. Most species generally have stable populations, although some have shown declines, while the numbers of the rest remain unknown.

According to the IUCN Redlist of endangered species, the tetra is considered least concern.

Tetra Predators and Prey

As tetras are small fish, many different predators hunt them. Larger fish, eels, crustaceans, and some invertebrates all feed on tetra. Because of their colorful bodies, predators can easily see tetras. When tetras feel they are in danger, they’ll often try to find somewhere to hide or swim to darker waters where they won’t be as visible.

In the wild and the aquarium, tetras eat almost anything because they are omnivores. The diets of wild and captive tetras are similar, with the exception that captive tetras eat manufactured food like flakes, pellets, frozen brine shrimp, etc. In the wild, they have access to a wide variety of foods. Among the favorite prey are common water fleas called daphnia, mosquito larvae, brine shrimp, bloodworms, and small fish eggs. In aquariums, tetras eat twice daily, consuming as much food as possible in about two minutes.

Tetra Reproduction and Lifespan

The lifespan of tetras is between eight to 10 years in the wild but considerably shorter in captivity. For example, neon tetras only live an average of five years. Tetras don’t live as long in captivity because of stress and boredom. Loneliness is also a factor as these fish do best when living in a school of other tetras.

Although most tetras are easy to care for, breeding them in captivity can sometimes be difficult because it’s hard to distinguish males from females. Even though they do not form monogamous pairs, tetras will not necessarily spawn with any other tetra they see and may reject their potential mate. The male tries to attract the female by dancing around her. If she likes him, she will take him to the spawning site. The number of eggs laid can range from 50 to 1,000, depending on the species. Tetras grow slowly. After hatching, it can take neon tetras two months to reach one-quarter inch in length. However, emperor tetras grow quickly as juveniles only take six months to become adults. Eggs take at least 48 hours to hatch.

Tetras in Fishing and Cooking

Generally, fishing for tetras only occurs to bring these fish into captivity to help populate home aquariums. Like most other aquarium fish, tetras are edible, but you probably wouldn’t want to do so. First off, their small size doesn’t produce much protein, but more importantly, you can run into digestive problems when consuming aquarium fish not explicitly raised for food.

Tetra Population

The exact number of tetras in the world is unknown, primarily because many of these fish live in remote regions and dark waters.

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