Fish Identification Photos: Deepbody Thread Herring, Opisthonema liberatate: The Deepbody Thread Herring has a wide body with a depth that is 38 percent of its length. It is grey-green on its back with silver white sides.

The Deepbody Thread Herring has clusters of black spots on the sides and the bases of the caudal and dorsal fins are yellow. It has a long filamentous ray originating from the last dorsal ray that extends to the caudal fin base. The Deepbody Thread Herring has long pectoral fins that reach past the dorsal fin origin.

A key to identification of the Deepbody Thread Herring is a gill raker count of 63 to 100. The Deepbody Thread Herring reaches a maximum length of 12 inches and is virtually weightless. It is normally found in the first 200 feet of the water column in small schools close to shore over sandy bottoms.

The Deepbody Thread Herring can be easily confused with the Middling Thread Herring, Opisthonema medirastre (body depth 36 to 38 percent, pectoral fin does not reaches dorsal origin; 41 to 69 gill rakers), the Slender Thread Herring, Opisthonema bulleri (body depth 31 to 32 percent; 25 to 36 gill rakers), and the Threadfin Shad, Dorosoma peteneuse (long anal tail base and a ventral profile with a strongly convex keel). The Deepbody Thread Herring is a common coastal pelagic species that is reported to be found in all Mexican waters.

The Deepbody Thread Herring is a member of the Clupeida family which consists of Herrings, Menhadens, Pilchards, Piquitingas, Sardines, Shads and Threadfin-herrings which are known in Mexico as sardinas.

Deepbody Thread Herring, Opisthonema liberatate: Commercially caught fish courtesy of Soriana’s Mercardo, Cabo San Lucas, Mexico, July 2008. Size 5.5 inches. Identification courtesy of H.J. Walker, Jr., Scripps Institute of Oceanography, La Jolla, Calif. Description and photo courtesy of John Snow. Deepbody Thread Herring, Opisthonema liberatate: Commercially caught fish courtesy of Soriana’s Mercardo, Cabo San Lucas, Mexico, July 2008. Also has been collected off the beach at Cabo Real in July 2008. Size 19.0 cm x 4.8 cm. Identification courtesy of H.J. Walker, Jr., Scripps Institute of Oceanography, La Jolla, Calif. Description and photo courtesy of John Snow.