Many suckers are identified by the configuration of these teeth. Some species have thin, comb-like pharyngeal teeth for filtering plankton directly from the water like Carpiodes and Ictiobus . Suckers, as their name implies, are mainly bottom feeders, foraging by sucking up materials from the bottom, separating out the indigestible detritus and ejecting it through the mouth and operculum. At other times some members of the family, mainly the buffalofishes, filter plankton for food directly from the water. The mouth of all suckers is located on the underside of the head and is tipped with fleshy protrusile lips.
Many suckers look like and are often confused with minnow species, but they differ in many features.
Most of the suckers have 10 or more dorsal fin rays, which is always one or two more than the native minnows. The pharyngeal tooth pattern is wholly different in the suckers. The suckers are well-adapted to bottom foraging. Being equipped with pharyngeal teeth and protrusile lips, they consume aquatic insects and their larvae, small mollusks, algae, detritus and minute crustaceans. They are able to find food items by both touch and taste, as well as by sight, and survive well in turbid waters.