Gizzard Shad (Dorosoma cepedianum)

Fish of the Mississippi River

Introduction

Short, silver, and tasty might be how other fish describe a gizzard shad. When young, gizzard shad are common forage for popular game fish. When surprised or pursued by predators, schools of young gizzard shad race to the surface and skip across the water on their sides.

However, gizzard shad quickly outgrow the vulnerable forage size and can rapidly assume pest levels in small lakes or when predator populations are insufficient to control their numbers. It also hosts early stages of several species of mussels which have commercial value.

Gizzard shad eat microscopic phytoplankton and zooplankton. Larger fish add algae and decaying organic matter to that diet. They also eat sand, which probably helps grind up food in their gizzard-like stomach.

Fascinating Facts

• Bass, pike, and walleye prefer eating soft-finned gizzard shad to spiny-finned bluegill.
• The gizzard shad is named for its muscular, gizzard-like stomach.
• It is also known as a sawbelly because of the keeled scales found between the anal fin and gills.

Identification

Key ID Features: Gizzard shad have a deep body with silvery blue back and white sides and a deeply forked tail. Average shad are 6-8 inches long and weigh1-8 ounces. Younger fish have a dark spot behind the gill flap. Its dorsal fin sports a long whip-like filament on the last ray.
Present in Park: Yes
Habitat: large rivers, reservoirs, lakes, swamps
MN Status: Common

For Further Reading

• Bosanko Dave. 2007. Fish of Minnesota. Cambridge, MN: Adventure Publications, Inc.
• Iowa Department of Natural Resources. 2017. Iowa Fish Species, Fish Details, Gizzard Shad. Available fro. http://www.iowadnr.gov/Fishing/Iowa-Fish-Species/Fish-Details/SpeciesCode/GZS