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

Bigmouth Shiner Ericymba dorsalis

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

This species was found at 732 bioassessment sites, 117 rapid fish bioassessment sites, 94 fisheries assessment sites, and 11 fisheries presence-only assessment sites. In total, it was collected at 884 distinct sites, or 60% of the 1473 total sites monitored by the bioassessment program. It is the 3rd most commonly collected species.

The Bigmouth Shiner was collected in 1431 bioassessment sampling sessions and 256 fisheries assessment sessions. It was present in 117 rapid bioassessment sessions and 11 presence-only sessions.

The biological assessment program has collected a total of 91,141 individual Bigmouth Shiner specimens, ranking it the #7 most collected fish.

Species Characteristics

A unique body form; slender, fairly flat-bellied and hump-backed. Their eyes appear to focus upward, when viewed from above, because the pupil is skewered dorsally. Body color is olive-yellow on the back and silvery on the sides and belly. A mid-dorsal stripe, running along the top of the body, is continuous around the base of the dorsal fin. There is no pigment around the vent or at the base of the anal fin. There is no lateral band, but the lateral line that has about 35 scales is complete with paired markings called "mouse tracks" at each pore. Scales in front of the dorsal fin are smaller, crowded, and exceed 16 in number. The sub-inferior mouth, found on the bottom of the head and overhung by the snout, is horizontal and does not have a barbel. Hooked pharyngeal teeth on slender arches are arranged in an array formula of 1, 4-4, 1. Dorsal, anal and pelvic fins have 8 rays, while the pectoral fins have 14 or 15 rays.

Species Distribution Maps

HUC12 watersheds where this species has been found