; subclass Actinopterygii, order Siluriformes)
A large family of small, bottom-dwelling, freshwater fish. The body is covered with tile-like scales, the head shows a rather steep profile, and the ventrally positioned mouth is surrounded by barbels. Several species, when exposed to oxygen-deficient water, can gulp in air and store it in the gut. There are about 130 species, occurring in the tropical rivers of S. America.
Subjects: Zoology and Animal Sciences.