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

Grass Carp Ctenopharyngodon idella

Cyprinidae (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 20 bioassessment sites, 0 rapid fish bioassessment sites, 3 fisheries assessment sites, and 0 fisheries presence-only assessment sites. In total, it was collected at 23 distinct sites, or 1.7% of the 1382 total sites monitored by the bioassessment program. It is the 85th most commonly collected species.

The Grass Carp was collected in 23 bioassessment sampling sessions and 3 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 114 individual Grass Carp specimens, ranking it the #92 most collected fish.

Species Characteristics

Elongate, chubby body that is torpedo-shaped. The body is dark olive, shading to brownish-yellow on the sides with a white belly and large, slightly outlined scales. The terminal mouth is slightly oblique with non-fleshy, firm lips, and no barbels. The complete lateral line has 40 to 42 scales. The dorsal fin has 8 to 10 soft rays, and the anal fin is set closer to the tail than most cyprinids. Broad, ridged pharyngeal teeth are arranged in a 2, 4-4, 2 formula.

Species Distribution Maps

HUC12 watersheds where this species has been found