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

Warmouth Lepomis gulosus

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

This species was found at 2 bioassessment sites, 0 rapid fish bioassessment sites, 0 fisheries assessment sites, and 0 fisheries presence-only assessment sites. In total, it was collected at 2 distinct sites, or 0.1% of the 1473 total sites monitored by the bioassessment program. It is the 120th most commonly collected species.

The Warmouth was collected in 2 bioassessment sampling sessions and 0 fisheries assessment sessions. It was present in 0 rapid bioassessment sessions and 0 presence-only sessions.

The biological assessment program has collected a total of 4 individual Warmouth specimens, ranking it the #129 most collected fish.

Species Characteristics

A thick-bodied, stout-looking fish with a rich olive-brown color on the back and sides. The sides are covered with dark brown mottlings, and the belly is light yellow. A characteristic feature is 4 or 5 reddish-brown streaks radiating from the eye across each side of the head. The iris of the eye is red, and the fins are spotted with dark brown, forming bands which are more noticeable on the soft parts of the dorsal and anal fin. It can easily be distinguished from other sunfish by the patch of small teeth on the tongue. Anglers often confuse this fish with the Rock Bass, but they are easily separated by counting the spiny rays in the anal fin; the Warmouth has 3 spines and the Rock Bass has 6 spines. The spiny dorsal fin, which is broadly connected with the soft part of the fin, has 10 spines.

Species Distribution Maps

HUC12 watersheds where this species has been found