The mouths of these fish are most commonly located on the underside of their head (subterminal), with thick, fleshy lips.

Their food ranges from detritus and bottom-dwelling organisms (such as crustaceans and worms), to surface insects, crayfish, small terrestrial vertebrates, and other fish.

An enormous gap (36.2 million years) in the fossil record occurs from the Late Eocene to Early Pleistocene.

Suckers have historically been scapegoated for human environmental destruction and their impacts on popular fish species such as Pacific salmon and smallmouth bass.

[12] Catostomidae is classified into the following subfamiles and genera:[13][1] The fossil genus Jianghanichthys was previously placed in the Catastomidae, but is now placed in its own family, Jianghanichthyidae.