Gizzard Shad (Dorosoma cepedianum)

Gizzard Shad (Dorosoma cepedianum)

A member of the Clupeidae family of herring and shad, the gizzard shad is important forage for large fish. However, its rapid growth rate causes it to exceed a consumable size for most predators early on in its life. It is often labeled a nuisance fish by anglers and biologists, due to large die-offs, which happen because the species is especially susceptible to drastic changes in temperature and low concentrations of oxygen.

Identification

The gizzard shad is one of two freshwater members of the herring family that has a distinctively long, slender last ray on its dorsal fin. The body is silver blue on the back and silver white underneath, with either blue-and-green or gold reflections on the head and the flanks.

Occasionally, there are six to eight horizontal dark stripes on the back, starting behind a large purple blue or black shoulder spot (which is faint or absent in large adults). The gizzard shad also has dusky fins, a blunt snout, a subterminal mouth, and a deep notch at the center of the upper jaw.


Size/Age

Growing to a maximum of 20.5 inches and averaging about 10 inches in length, this species commonly reaches more than a pound in weight but has grown to over 4 pounds. Most gizzard shad die before they reach age 7, although they can live up to 10 years.

Life history

Gizzard shad occur in schools and are first able to spawn when 2 to 3 years old or 7 to 13 inches long. They breed near the surface in freshwater from March through August, when water temperatures range from 50° to 70°F. They roam open waters in search of plankton, which occurs at various levels, according to the season and conditions.

Food and feeding habits

Gizzard shad are filter feeders that strain microscopic organisms from the water or pick through mud and organic matter on the bottom.

Other Names

shad, eastern gizzard, hickory shad, mud shad, nanny shad, skipjack, winter shad.
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