One of a large group of small, gregarious, streamlined whales or one of two species of oceanic sport and food fishes.
Mammalian dolphins are small toothed whale s, usually with a well-defined, beaklike snout. (They are sometimes called porpoise s, but that name is properly reserved for a blunt-snouted whale family.) The common dolphin ( Delphinus delphis ) and the bottlenose dolphin , both of the family Delphinidae, are found widely in warm temperate seas, though some inhabit tropical rivers. Most of the 32 delphinid species are marine; gray, blackish or brown above and pale below; and about 3–13 ft (1–4 m) long. River dolphins (family Platanistidae; five species) live mainly in fresh water in South America and Asia. One of the two fish species, Coryphaena hippuras (family Coryphaenidae), also called mahimahi and dorado, is a popular fish of tropical and temperate waters worldwide. The pompano dolphin ( C. equiselis ) is similar. See also killer whale .
Bottle-nosed dolphins ( Tursiops truncatus )
By courtesy of the Miami Seaquarium