How to Identify Gizzard Shad

To identify Gizzard Shad (Dorosoma cepedianum), look at these key features.

Physical Characteristics

Body shape

compressed

Coloration

Silvery sides, darker blue-gray to olive-green back, and a white belly. A distinct dark spot is often present behind the operculum (gill cover) in juveniles and sometimes in adults.

Scale type

cycloid

Mouth position

subterminal

Distinctive features

Deep, compressed body, Small, subterminal mouth, Elongated last ray of the dorsal fin (filamentous), Keeled belly with sharp scutes (serrated scales), Large, cycloid scales

Dorsal fin

Single dorsal fin, typically with 10-13 rays, the last ray greatly elongated into a filament that can extend past the caudal fin base in adults.

Tail fin

Deeply forked caudal fin.

Pectoral fin

Relatively small, positioned low on the body.

Distinctive fins

Pelvic fins are small and abdominal. Anal fin is long, with 25-33 rays.

Identification Tips

1. 1

   Dorsal Fin Filament

   Look for the greatly elongated last ray of the dorsal fin, which is a key distinguishing feature. This filament can be as long as or longer than the rest of the fin.

2. 2

   Mouth Position

   The mouth is small and subterminal (located on the underside of the head, not at the very front), adapted for filter feeding.

3. 3

   Body Shape and Coloration

   Deep, compressed, silvery body with a darker back. A dark shoulder spot is often present, especially in younger individuals.

4. 4

   Keeled Belly

   Feel the belly; it will be sharp and serrated due to the presence of scutes.

Explore Gizzard Shad