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

Brook Stickleback Culaea inconstans

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

This species was found at 161 bioassessment sites, 37 rapid fish bioassessment sites, 32 fisheries assessment sites, and 19 fisheries presence-only assessment sites. In total, it was collected at 225 distinct sites, or 16.7% of the 1350 total sites monitored by the bioassessment program. It is the 32nd most commonly collected species.

The Brook Stickleback was collected in 252 bioassessment sampling sessions and 53 fisheries assessment sessions. It was present in 37 rapid bioassessment sessions and 20 presence-only sessions.

The biological assessment program has collected a total of 3,453 individual Brook Stickleback specimens, ranking it the #44 most collected fish.

Species Characteristics

A deep-bodied, compressed and scaleless fish. The mouth is small with swollen lips, and the lower jaw projects beyond the upper jaw. There are two to seven (usually five) unconnected spines followed by a dorsal fin with 9 to 11 rays. The anal fin has a single spine with 9 to 10 rays; the pelvic fin has one heavy spine with a single ray. The lateral line is complete, and there are 30 to 36 small, bony plates along its full length. It is olive-green on the back and sides with white or yellow spots and dark wavy lines scattered over the sides. This species reaches 2- to 3-inches long.

Species Distribution Maps

HUC12 watersheds where this species has been found