slender, fine-scaled sucker; tinted dark greenish along back; sides with brassy or silvery luster; white belly, lips with numerous wart-like projections
statewide, mostly in small rivers and streams
variety of bottom organisms; growth up to 18.5 inches at ten years of age, most fish much smaller
most white suckers are caught accidentally by anglers fishing with worms on the bottom of streams
The white sucker is widely distributed in Iowa. It is abundant in small rivers and streams, common in natural and man-made lakes, occasional in the Mississippi River and large tributary rivers, and rare in the Missouri River. Highly adaptable to differing habitats and changing environmental influences, it is relatively tolerant of turbid and polluted waters.
The white sucker is a slender, fine-scaled sucker that is tinted dark greenish along the back and sides, with a brassy or silvery luster on the sides and a white belly. The dorsal and tail fin are dusky to clear. Breeding males may become very dark colored and develop tubercules over the head, fins and body. Adults commonly reach 10 to 16 inches in length and weigh up to 2 pounds.
The distinctive characteristic that separates this species from other suckers and redhorses is a complete lateral line containing 55-85 small scales. The lips are fleshy and heavy with numerous small, wart-like projections. The dorsal fin is straight or slightly concave with 10-13 rays, anal fin with 7 rays, and the pelvic fin with 10-11 rays. Sexual dimorphism may occur in adult brood fish. White sucker are known to hybridize with closely related catostomids.
Spawning commences with migratory spring runs that may be initiated by runoff from early snow melt. Actual spawning occurs in late spring when water temperature ranges from 57 to 68 degrees F. Eggs are broadcast at random and they are adhesive. Eggs incubate in 5 to 7 days. Spawning males are gregarious, occupying spawning shoals before the females. Several males may spawn a single female; often times two males spawn a single female similar to the behavior of redhorses. Spawning takes place in swift or flowing water over bottom substrates of rubble or gravel. Fecundity of a 19-inch female is around 93,000 eggs. Both sexes of white sucker mature at age II. Growth of white sucker ranges from 7.0 inches at age I to 18.5 inches at age X. This species has diverse feeding habits, taking almost any food that is available. They are principally bottom feeders making aquatic insect larvae, small mollusks, crustaceans, and various terrestrial worms preferred food items.
White suckers are a natural prey species for northern pike, muskellunge, walleye, sauger, largemouth bass and smallmouth bass. Juvenile suckers are often cultured for food in the propagation and rearing of predatory fish. They are often sold as bait fish.