This is one of the most widespread and abundant suckers, found only in North America.
IdentificationWhite suckers are inconspicuously colored, usually in drab hues of white, yellow, and pink. The upper half of the ﬁsh is typically more darkly colored than the lower half. Although an adult has little dark pigmentation, a juvenile has three lateral black blotches halfway up the side of the body: one between the dorsal ﬁn and opercle, one below the dorsal ﬁn, and one on the caudal peduncle. The body is elongate and nearly circular in cross-section. The white sucker has rather small scales that get larger near the posterior.
Age/SizeThe white sucker is a medium-size ﬁsh, reaching up to 18 inches or more in length and up to 8 pounds in weight. The largest individuals may be as old as 17 years, but the normal life expectancy is between 12 and 15 years. Sexual maturity is reached at about the same time in both sexes. The ﬁrst spawning occurs between 3 and 5 years of age, depending on the region.
Life history/Spawning behaviorWhite suckers make long upstream spawning migrations in the early spring. The spawning season may extend from late March into early July in some areas. Upstream migration may be triggered by increasing water temperature or stream ﬂow that occurs during this time of year. The suckers move into deep pools and congregate before spawning. They then gather and spawn in areas of clean gravel substrate.
Males and females line up next to each other on the bottom of the stream, then shake violently, releasing eggs and sperm as they bury the eggs in the substrate. In lakes, they perform this activity in shallow shoals or may move upstream into rivers. White suckers darken in coloration during spawning. The male becomes olive colored on the upper portion of the body and may develop a pinkish lateral stripe.
Food and feeding behaviorLike most suckers, this species feeds on a variety of benthic organisms and organic nutrients. Its primary diet includes burrowing insect larvae that are sucked up and sifted in its gill rakers. Midge larvae, small crustaceans, algae, and detritus are the most common