There are 80 species in this family of freshwater fishes. Catostomidae are found in North America, east central China, and eastern Siberia. Their mouth is located on the underside of the head (subterminal), with thick, fleshy lips. Most species are less than 60 cm (2 feet) in length but the largest species can reach 1 m (40 inches). They are not usually fished recreationally; they are not highly prized in North America for their flesh although they are a fairly popular target with spear fisherman.

Catostomids are most often found in rivers but can be found in any freshwater environment. Their food ranges from detritus and bottom dwelling organisms (such as crustaceans and worms), to surface insects and small fishes.

Longnose Sucker

The longnose sucker, Catostomus catostomus, is a freshwater species of fish inhabiting cold, clear waters in North America from northern USA to the top of the continent. In addition, it is the only species of sucker to inhabit Asia, specifically the rivers of eastern Siberia. The body of the longnose sucker is long and round with dark olive or grey sides and top and a light underside. They are typically 15 - 25 inches long and weigh between one and two lb.

The longnose sucker is a bottom-feeding fish, eating aquatic plants, algae, and small invertebrates. They are preyed upon by larger predatory fish, such as bass, walleye, trout, northern pike, muskellunge, and burbot. They are fished for game and food and also used as bait to catch the larger predators.

Longnose suckers are often confused with white suckers, as they appear very similar.