The last dorsal fin ray on both the gizzard and threadfin shad is elongated and whip-like. The gizzard shad, however, is the only member of this family with a blunt snout and an inferior mouth. The ventral edge of the upper jaw is deeply notched. Lateral scales number between 59 and 67; a lateral line is lacking. The anal fin has 29 to 35 fin rays; the dorsal fin, 10 to 13. The back is bluish gray. Freshly caught individuals may have a greenish or silver tinge overall, as well as several darker, horizontal bars along the sides. The venter is milky white to silver. The color of the vertical fins is variable, from nearly black during the spawning season to clear with irregular black blotches in the fall. See Lesueur (1818a) for original description.
7.9 to 12 in (200 to 305 mm)
Gizzard shad are abundant throughout the Tennessee and Chattahoochee rivers and the Mobile basin. They are much less abundant in the Choctawhatchee and Conecuh rivers. Their absence from the Escatawpa, Perdido, Yellow, and Blackwater rivers may be real or only apparent, the result of riverine sampling conducted without proper gear.
HABITAT AND BIOLOGY:
This schooling, pelagic species feeds primarily on plankton. Although individuals occasionally enter large streams, they occur in greatest abundance (frequently estimated at 2,000 to 4,000 pounds per acre) in open, quiet waters in rivers and reservoirs. The species can endure moderate salinity, as evidenced by our collections in the Dog and Fowl river systems in Mobile County and in the Fish and Magnolia river systems in Baldwin County. Mass spawnings occur primarily at night in open water from April through June. The tiny adhesive eggs float on the currents, where they remain until the larvae hatch. Gizzard and threadfin shad are sensitive to abrupt changes in temperature and dissolved oxygen content. This species is prone to large-scale, unexpected die-offs in late summer.
When using gizzard shad as live bait, protect them from physical stress by keeping them in the circulating water of round live wells.
Lesueur described gizzard shad in 1818.
Dorosoma means lance-shaped body.
Cepedianum means in honor of Citoyen Lacépède, the French ichthyologist.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin. Alabama Wildlife and Freshwater Fisheries Division protects this fish from capture or possession.