''Opisthonema'' is a genus of

herring Herring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, i ...

s, the thread herrings, found in tropical waters of the

Western Hemisphere The Western Hemisphere is the half of the planet Earth that lies west of the prime meridian (which crosses Greenwich, London, United Kingdom) and east of the antimeridian. The other half is called the Eastern Hemisphere. Politically, the term We ...

. They get their name from a filamentous nature of the last ray of the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

. Currently, five species are in this genus.

Species

* ''O. berlangai''

Berry A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...

& Barrett, 1963 (Galapagos thread herring) * ''O. bulleri]'' ( Charles Tate Regan, Regan, 1904) (slender thread herring) * '' O. libertate'' ( Günther, 1867) (Pacific thread herring) * ''O. medirastre'' Berry & Barrett, 1963 (middling thread herring) * '' O.oglinum'' ( Lesueur, 1818) (Atlantic thread herring)

References

* Clupeidae Marine fish genera Taxa named by Theodore Gill {{Clupeiformes-stub