Carp (Cyprinus carpio), a bony, fresh-water fish, in the physostomatus division, and type of the large family Cyprinidae. The body is covered with large scales; the head is naked; the wide, thick-lipped, terminal mouth is toothless, but there are teeth in the throat; a small barbule occurs on the upper jaw, and a large one at the corner of the mouth; the dorsal fin is long, the anal short, and both have the third ray strong and toothed; the hind-fins lie about the middle of the ventral surface. The back is blackish gray or brown, the sides yellowish brown, the belly yellow. At the reproductive season the male bears white or brown tubercles on the head and sides. The usual length is between 1 and 2 feet, but large forms 5 feet long or more have been caught.
The carp is mainly vegetarian, but also eats small animals, such as larvae and worms. The general habit is sluggish, except at the spawning period in May and June. The fecundity is very great; a single ovary of a moderate-sized specimen contains 700,000 or so eggs. They prefer ponds and the quiet parts of rivers. In winter they hibernate in the mud. Their longevity is great; some are said to have lived one hundred and fifty to two hundred years. The original home of the carp was in the central regions of Asia and probably also Europe, but it has been artificially spread everywhere—for instance in North America. They may be kept alive for weeks in damp moss; but are liable to skin diseases, and grow gray with mould. The carp was introduced into England before the 15th century. Fancy varieties have been reared, such as the King-carp, with few rows of large scales, and the Leather-carp, which is quite naked. C. Kollarii is a hybrid between carp and crucian (Carassius), or German carp, which like the Gibel (C. Gibelio) or Prussian carp, has no barbules. The Goldfish (q.v.) is C. auratus. The carp is a difficult fish for the angler, as it is by no means a free biter. It is an important food fish, and is easily bred. A good carp-pond, in Germany especially, is a by no means unimportant source of income. The carp is largely bred in the United States.