common name for the Cyprinidae, a large family of freshwater fish which includes the carp (Cyprinus carpio), and of which there are some 2,400 species. Minnows have soft-rayed fins and teeth in the throat only. Together with the closely allied sucker family and with the catfishes they form the “hearing-aid” group of freshwater fishes, so-called for the complex set of bones extending from the airfloat to the inner ear, which gives them a superior sense of hearing and accounts for their characteristic wariness.
The carp is generally considered the largest of the minnow family, although the pikeminnows, or squawfishes, of the Columbia and Colorado rivers average 30 lb (13.5 kg) and the mahseer, a game fish of India, is also large. However, most minnows are small. They have great importance in the cycle of freshwater aquatic life, since they consume aquatic insects, larvae, and crustaceans and in turn serve as food for many larger fish. Most species are dully colored, though a few are brilliantly hued in greens, reds, and yellows.
Various members of the family are called shiners, chubs, daces, roaches, breams, and bleaks; many of the American species are called shiners. The most widespread American minnow is the common shiner, Luxilus cornutus or Notropis cornutus. The Eurasian minnow is Phoxinus phoxinus. The creek chub and the golden shiner, a greenish fish that turns golden during the breeding season, attain a length of 12 in. (2.5 cm). The red shiner and redbelly dace are also named for the seasonal color changes in the male. The goldfish, genus Carassius, is also a member of the minnow family.
Certain varieties of killifish of the family Cyprinodontidae are called topminnows and toothed minnows. The carnivorous mudminnows of the family Umbridae, found in the sluggish waters in the Great Lakes region and the Atlantic coastal lowlands, superficially resemble toothed minnows but are more closely related to the pike; they are also called dogfishes.
Minnows are classified in the phylum Chordata, subphylum Vertebrata, class Actinopterygii, order Cypriniformes, family Cyprinidae.