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

Gizzard Shad Dorosoma cepedianum

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

This species was found at 149 bioassessment sites, 4 rapid fish bioassessment sites, 25 fisheries assessment sites, and 0 fisheries presence-only assessment sites. In total, it was collected at 177 distinct sites, or 13.7% of the 1294 total sites monitored by the bioassessment program. It is the 35th most commonly collected species.

The Gizzard Shad was collected in 223 bioassessment sampling sessions and 25 fisheries assessment sessions. It was present in 4 rapid bioassessment sessions and 0 presence-only sessions.

The biological assessment program has collected a total of 14,263 individual Gizzard Shad specimens, ranking it the #21 most collected fish.

Species Characteristics

Gizzard Shad have the typical herring body shape with a deep, oblong body that is strongly compressed laterally. Color ranges from bright silvery-blue on the back, silvery sides and a dusky-white on the belly. A dark shoulder spot is common on younger fish, but may be absent from adults. The front of the head is rounded with a sub-terminal mouth. Teeth are absent. There are about 190 rakers on the lower limb of the first gill arch. The eyes have adipose eyelids with vertical slits. Body scales are cycloid with no lateral line present. The ventral scales are keeled. Dorsal fin rays number 10 to 12 with the last ray elongated into a thin whip-like filament. This fin is inserted slightly behind the pelvic fin. An auxiliary process is present at the base of the pelvic fin. The anal fin has 27 to 34 rays, and the caudal fin is deeply forked.

Species Distribution Map