United Reptiles - Prehistoric World Today
A tetra is one of several species of small freshwater fish from Africa, Central America, and South America belonging to the biological family Characidae and to its former subfamilies Alestidae (the "African tetras") and Lebiasinidae. The Characidae are distinguished from other fish by the presence of a small adipose finbetween the dorsal and caudal fins. Many of these, such as the neon tetra (Paracheirodon innesi), are brightly colored and easy to keep in captivity. Consequently, they are extremely popular for home aquaria.
Tetra is no longer a taxonomic, phylogenetic term. It is short for Tetragonopterus, a genus name formerly applied to many of these fish, which is Greek for "square-finned" (literally, four-sided-wing).
Tetras are small sizes fish that do well in schools or groups of 4 or more fish. They do require some attention to the water qaulity and vulnerable to more aggresive tank mates. Availible in a large variety to suite eveyones needs.