Tetras

Tetras

Most tetras are small or medium size fish mostly belonging to the Characin family. They come from South America and Central American with a few from Africa. Many of these fish are almost incredibly beautiful. Most of the South American tetras come from soft, acid water.

There are hundreds of different types of tetras, but it isn’t a rigidly scientifically defined group, so an exact count is impossible. Many people have given a total number of tetras, and 150 is one of them.

At the end of my book, Tetras, I explain my own count that I did a few years ago, suggesting that there are at least 888 scientifically described fish that can reasonably be called tetras. This is based on the total number of species in all the genera I can find that have at least one species commonly referred to a a tetra.

While there are an enormous number of species of fish, including hundreds of types of tetra, from the extremely wet eastern side of the Andes mountains, there are not so many to the west of this mighty mountain range. The mountain range is not only much closer to the sea, but part of the area to the west is extremely dry.

The fish on the west include several species of Cheirodon, but none of the more popular tetras. The Uruguay Tetra, Cheirodon interruptus, is a tetra found in a river leading to Pacific Ocean, as well as in rivers leading to the Atlantic.