Atlantic Thread Herring

Opisthonema oglinum, the Atlantic thread herring, is a small, marine, pelagic fish in family Clupeidae.Its common name refers to its last dorsal fin ray, which is long and filamentous and distinguishes O. oglinum from other most other western Atlantic clupeids (except several species of genus Dorosoma, which differ in having an inferior mouth).Atlantic thread herring have a blue or green dorsal surface and several dark lateral stripes along their silvery body.

Atlantic tread herrings form dense surface schools feeding mainly on copepods.They occur in near shore habitats from Brazil, along the coast Gulf of Mexico to the Atlantic reaching as far north as Cape Cod, Massachusetts but more abundantly in the southeast between Florida to North Carolina.Atlantic schools migrate south in the fall and overwinter in southern Florida; during this time several coastal fish species prey on them, including king mackerel (Scomberomorus cavalla), Spanish mackerel (S. maculates), bluefish (Pomatomus saltatrix) and crevalle jack (Caranx hippos).

Faster and more agile than the Atlantic menhaden (Brevoortia tyrannus), and harder to catch in purse seines, Atlantic thread herrings are harvested by fisheries in small amounts.Some of the harvest is salted or marketed fresh for human consumption but most is used for bait and pet food or processed as fishmeal and fish oil (Smith 1986; Whitehead 1985).

The filamentous last dorsal fin ray distinguishes this species from all other western Atlantic clupeoids except Dorosoma, which has an inferior mouth (Ref. 188). Otherwise, superficially resembles species of Sardinella (but i 8 pelvic fin rays in western Atlantic species, cf. i 7 in Opisthonema) and Harengula (but small toothed hypomaxilla in upper jaw) (Ref. 188). Lower gill rakers stable at 28 to 46 after 8 cm (Ref. 188). Silvery, with a bluish or greenish back, 6-7 lengthwise dark streaks on side. Dark spot above opercle, larger dark spot behind opercle, usually with a row of dark spots behind it. Lower profile deeply curved. Head pointed (Ref. 7251).

Contracaecum Infestation 3. Parasitic infestations (protozoa, worms, etc.)

Possibly breeds in March-July off Venezuela.

Dorsal spines (total): 0; Dorsal soft rays (total): 19 - 21; Analspines: 0; Analsoft rays: 23 - 24

Inhabit harbors and shallow coastal areas (Ref. 9710). Form schools (but solitary individuals reported), probably not entering water of low salinity. Feed by filtering plankton (copepods), but also take small fishes, crabs and shrimps.

Inhabit harbors and shallow coastal areas (Ref. 9710). Pelagic (Ref. 27549). Form schools (but solitary individuals reported), probably not entering water of low salinity. Feed by filtering plankton (copepods), but also take small fishes, crabs and shrimps. Marketed fresh, frozen and salted; also used in the fishmeal industry. Occur in freshwater in St. Johns River, Florida (Ref. 26938).

fisheries: commercial; bait: usually

The Atlantic thread herring (Opisthonema oglinum) is a herring-like fish in the family Clupeidae.

It has a dark blue-gray back, silvery sides, a white belly, and a small head. It grows up to 38 cm in length. It can be found in shallow waters and harbors along the coasts of the western Atlantic Ocean, from Cape Cod south to Brazil, including the Gulf of Mexico. It feeds mainly on plankton, but also takes small fish and crustaceans.

It is confused with the scaled sardine, Harengula jaguana, by anglers.

Western Atlantic: from Gulf of Maine (USA), Bermuda, throughout the Gulf of Mexico, Caribbean and West Indies southward to Santa Caterina, Brazil