The White Sucker (Catostomus commersonii) is a common freshwater fish found throughout North America. They typically grow up to 20 inches long and have a cylindrical, elongated body wit... The White Sucker (Catostomus commersonii) is a common freshwater fish found throughout North America. They typically grow up to 20 inches long and have a cylindrical, elongated body with a rounded snout. White Suckers are bottom feeders, using their fleshy lips to suck up algae, detritus, and small invertebrates from the substrate. They are an important food source for predatory fish and are occasionally caught by anglers.Click here to read more about White Sucker.