California Fish Species: Gizzard Shad

The Gizzard Shad, a member of the herring family, is native to fresh and salt waters of eastern North America. Its natural range includes the Saint Lawrence River and the Great Lakes and extends west into North Dakota. Gizzard shad are found as far south as eastern Mexico, and as far west as New Mexico. Its range has been greatly expanded through stockings throughout the west.  Preferred habitat is sluggish rivers and muddy bottomed lakes, avoiding fast waters.  Shad are pelagic and frequently feed near the surface. Gizzard shad are sensitive to sudden changes in temperature and oxygen content, which can cause large-scale, unexpected die-offs.
 
Gizzards have a deep, oblong body. Free of markings, they are grayish or silvery blue on top transitioning to silver on the sides with a whitish belly. The dorsal fin has a long ray that extends beyond the rest of the fin. The tail fin is deeply forked. Their mouth is inferior, sub-terminal, and toothless. Gizzard shad produce excessive slime and have a noticeable strong “fishy” smell. 
Eight to fourteen inches is typical for gizzard shad, but can exceed 18 inches.
 
Gizzard shad spawn in the spring, when water temperatures rise above 50 degrees Fahrenheit. Diverse habitats are utilized for spawning. Eggs and sperm are broadcast simultaneously near the surface.  The eggs sink to the bottom and adhere to submerged objects.  Reservoir populations often spawn in creeks tributary to the reservoir. Shad are prolific, producing up to 400,000 eggs.
 
This schooling, pelagic fish is primarily a plankton feeder. They ingest bottom mud and sand to assist grinding of phytoplankton and zooplankton in their thick walled gizzard like stomachs.