characin

characin , common name for members of the Characidae, a large and diverse family comprising 700 species of freshwater fishes. The characins are related to the carp and the catfish. They are found in Africa and in tropical America, especially in the Amazon. Most species are active and predacious. Most notorious are the piranhas, or caribes ( Serrasalmus species), with their powerful jaws and razor-sharp triangular teeth, capable of killing humans and cattle. Various small, colorful characin species, called tetras, are used in aquariums. A small characin found in Mexican streams is interesting for the stages of blindness it exhibits: those living deep in caves are eyeless; those found near the entrance have imperfect eyes; and the specimens living in open water have normal eyes. A cross of a blind with a normal specimen produces offspring with varying degrees of eye degeneracy. Characins are classified in the phylum Chordata , class Osteichthyes, order Cypriniformes.

characin See CHARACIDAE.

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.