Herring

Herring, common name for several fishes characterized by a single short dorsal fin in the middle of the upper margin of the body and by an anal fin similarly located below. The head is scaleless, and the slender body is covered with thin, cycloid scales in which rings of organic material, rich in guanine (see Guano), are laid down each season. By counting these rings scientists can determine the age of the fish, which may live up to 20 years.

Herrings are economically the most important group of fish to North America and western Europe. The 199 species of the most widespread family include the menhaden, the pilchard (the young of which are common sardines), and the shad. They are saltwater fishes abundant throughout the North Atlantic Ocean, in the North and Baltic seas, and in the North Pacific Ocean. Most swim near the surface of the water in huge schools and feed on plankton. They are about 30 cm (about 12 in) long when mature. The denticle herring is a freshwater fish inhabiting rivers in southwestern Nigeria. The wolf herring has fanglike teeth and preys on other fish; it is found in the Indian Ocean and the Western Pacific.

Spawning activity is quite varied. Some, such as the American shad, migrate into rivers and spawn in fresh water. Others, such as the Pacific sardine, spawn offshore in spring and summer and have eggs that float at the surface. The Pacific herring and the Atlantic herring spawn in shallow bays and deposit their eggs on seaweeds and shells.

Herrings mature at three to four years of age in the North Sea, at five to eight in the Baltic Sea, and even later in the Bering Sea. Herrings of southerly seas die at an earlier age; consequently, those found in the north grow to a larger size.

The term herring, when unqualified, usually refers to the Atlantic herring. This fish, abundant in the Atlantic Ocean and found along the coast of the United States north of South Carolina, grows to a length of 30 cm (12 in) and is bluish-green above, silvery below. The young, and the young of the European sprat, are often called whitebait and are considered table delicacies. The Pacific herring, found from Alaska to Mexico, is a similar fish. The fall herring, so called because it spawns in the fall, is found south of Cape Cod; it is sometimes called hickory shad. The blueback, also known as the summer or glut herring, ascends into fresh water to spawn. Another common herring is the spring herring, or alewife.

The name herring is also applied to several freshwater fishes, such as the lake herring, or cisco, of the Great Lakes, and the rainbow herring, a smelt. The chimera, an ocean fish, is sometimes called king of the herrings.

Herrings are important ecologically because they are a direct link in the food chain between tiny plankton and large marine predators. Plankton is consumed by the herring, which then become a food source for sharks, sea lions, birds, crabs, seals, whales and humans.

The fishing, processing, and marketing of different species of the herring family is a major industry in the United States, the United Kingdom, Norway, Denmark, the Netherlands, Germany, France, and Portugal. Besides fresh and salted herring, the products of this industry on the market include red herring, which has been smoked until it is hardened; kippered herring, which is slightly salted and partially smoked; bloaters, which are large herrings that are heavily salted and partially smoked; and canned sardines.

See also Fisheries.

Scientific classification: Herrings belong to the order Clupeiformes. The menhaden, pilchard, and shad belong to the family Clupeidae. The denticle herring belongs to the family Denticipitidae. The wolf herring makes up the family Chirocentridae. The American shad is classified as Alosa sapidissima. The Pacific sardine is classified as Sardinops sagax. The Pacific herring is classified as Clupea harengus pallasi, and the Atlantic herring is classified as Clupea harengus harengus. The European sprat is classified as Clupea sprattus. The fall herring is classified as Alosa mediocris, the blueback is classified as Alosa aestivalis, and the spring herring is classified as Alosa pseudoharengus.