cavefish, common name for blind, cave-dwelling fishes of the family Amblyopsidae. The Amblyopsidae are mostly whitish fish, up to 5 in. (13 cm) long. With the exception of a single species, all members of the family live in the limestone cave region of the Mississippi basin. The species that live in caves have nonfunctioning rudimentary eyes. Two species, the springfish and the ricefish (or riceditch killifish), have small, functional eyes. The ricefish, which superficially resembles the toothed minnow, is found in streams and swamps of the SE United States. Other, unrelated fish also live in cave and have rudimentary or nonexistent eyes. The cavefish and their relatives are classified in the phylum Chordata, subphylum Vertebrata, class Actinopterygii, order Percopsiformes, family Amblyopsidae.