Tetra is the common name of many small freshwater characiform fishes. Tetras come from Africa, Central America, and South America, belonging to the biological family Characidae and to its former subfamilies Alestidae and Lebiasinidae.

Tetras are active schooling fish that work well in the peaceful community aquarium. It is ideal to keep six or more fish of the same tetra species in the aquarium. Tetras do best in a well-planted aquarium with moderate lighting.