Clupea

Clupea is a genus of ray-finned fishes in the family Clupeidae, order Clupeiformes, commonly known as herrings. The genus comprises two widely recognized species: the Atlantic herring (Clupea harengus) and the Pacific herring (Clupea pallasii).

Physically, Clupea species are small to medium-sized, laterally compressed, with a streamlined, silvery body and a single dorsal fin. They typically reach up to about 40 cm in length. They inhabit cold temperate coastal and shelf waters of the Northern Hemisphere, forming large schools in open seas but often concentrating near coastlines during spawning runs or feeding.

Biology and ecology show that these fishes are planktivores, feeding mainly on zooplankton and small crustaceans, and they serve as a crucial prey item for many marine mammals, seabirds, and larger fish. Reproduction occurs in coastal shallows in spring or early summer; eggs are adhesive and attach to vegetation or substrates. Larvae feed on microplankton until they grow to juvenile stage. Their migratory patterns vary by species and season, but both tend to move between feeding grounds and spawning areas.

Economic and conservation notes: Clupea species are among the most important commercial fish in northern waters, supporting fisheries for human consumption, fish oil, and fish meal. Populations are managed to prevent overfishing, with quotas, seasonal closures, and other measures in many regions. Because of their abundance and role as a key trophic link, changes in Clupea stocks can have wide-ranging effects on marine ecosystems.