Iowa DNR
River & Stream Biological Monitoring
Fish and Benthic Macroinvertebrate Surveys
Physical Habitat Assessments

White Sucker Catostomus commersonii

Catostomidae (Suckers)
Trophic Class
Is Exotic to Iowa?
Is Lithophilous Spawner?
Is Hybrid?
State Listing Status
Not Listed
Assessment Program Statistics

This species was found at 677 bioassessment sites, 111 rapid fish bioassessment sites, 137 fisheries assessment sites, and 49 fisheries presence-only assessment sites. In total, it was collected at 891 distinct sites, or 64.5% of the 1382 total sites monitored by the bioassessment program. It is the 2nd most commonly collected species.

The White Sucker was collected in 1387 bioassessment sampling sessions and 399 fisheries assessment sessions. It was present in 111 rapid bioassessment sessions and 61 presence-only sessions.

The biological assessment program has collected a total of 117,914 individual White Sucker specimens, ranking it the #4 most collected fish.

Species Characteristics

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. The distinctive feature that separates this species from other suckers and redhorses is a complete lateral line with 55-85 small scales. Its lips are fleshy and heavy with many 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. Adults commonly reach 10- to 16-inches long and weigh up to 2-pounds.

Species Distribution Maps

HUC12 watersheds where this species has been found