The Utah sucker, Catostomus ardens, is a sucker of the family Catostomidae found in the upper Snake River and the Lake Bonneville areas of western North America.
This is a large fish, up to 25.59 in (65 cm) in length. Relatively elongate for a sucker, the back area between the head and dorsal fin is somewhat elevated. The mouth is entirely under the snout, with thick lips, of which the upper lip has eight rows of coarse papillae, the second and third rows from the inside being significantly larger. Color is generally blackish above, with a faint pattern of blotches or spots, a narrow rosy band on the anterior part of each side, while the underside is white. The long anal fin is placed well back, the tip reaching as far back as the base of the caudal fin. The anal fin has 7 rays, while the dorsal has 13 rays.
It lives in a variety of habitats in its range, being found in lakes, rivers, and streams, in warm or cold water, and over substrates of silt, sand, gravel, or rocks, preferably in the vicinity of vegetation. Some populations may be in decline. Recent genetic studies have revealed deep, but morphologically cryptic, subdivision between populations in drainages of the ancient Snake River and the Bonneville Basin.
In 1881, David Starr Jordan and Charles Henry Gilbert observed that this sucker “occurs in Utah Lake in numbers which are simply enormous”; the population seems to have boomed and crashed several times since then.
Nomenclature for this species has been long confused, with this fish being confused with the June sucker, Chasmistes liorus, in the 1870s, and the name Catostomus fecundus being used for a time.