Characidae (characin, tetra, piranha; subclass Actinopterygii, order Cypriniformes) A very large family of freshwater fish. Most are small in size and some are very colourful. All have a single dorsal fin on the back, often a small adipose dorsal fin, a forked tail fin, and an anal fin which often is larger than the dorsal fin. Many species are extremely popular aquarium fish. Anoptichthys jordani (blind cavefish) lives in cave waters; its body lacks pigment and its eyes are vestigial. The family also includes the voracious piranhas, powerfully built fish with strong jaws and teeth. Serrasalmus rhombeus (white piranha) can grow to a length of 30 cm and appears to be a good table fish. There are about 500 species, found in Central and S. America and in Africa.

characin See CHARACIDAE.