Clupeiformes

an order of bony fishes. The body is usually silvery and laterally compressed. The pectoral fins are placed low, and the ventral fins are usually in the middle of the abdomen. There is a single, spineless dorsal fin. The fishes usually range in length from 5–6 to 60 cm and in weight from a few grams to 0.5 kg. Only a few species reach a length of 2–2.4 m. The scales are cycloid.

The order contains 15 suborders, embracing about 50 families. Amont the more important families are Clupeidae (herring), Engraulidae (anchovies), Salmonidae (trout), Thymallidae (graylings), Osmeridae (smelts), Daliidae (with the single species Dallia pectoralis), Chanidae (milkfishes), Esocidae (pikes), and Arapaimidae (with the single species Arapaima gigas). Some ichthyologists place a number of families into separate orders (for example, the orders Isospondyli and Haplomi).

The fishes of the order Clupeiformes are distributed in many seas and in some brackish and fresh waters. They are extremely important in commercial fishing, making up as much as one-fifth of the world’s fish catch.