The Spinner Dolphins is a small dolphin found in off-shore tropical waters around the world. It is famous for its acrobatic displays in which it spins along its longitudinal axis as it leaps through the air. It is a member of the family Delphinidae of toothed whales.
The spinner dolphin is a small cetaceans with a slim build. Adults are typically 129–235 cm and reach a body mass of 23–79 kg. This species has an elongated rostrum and a triangular or sub-triangular dorsal fin. Spinner dolphins generally have tripartite color patterns. The dorsal area is dark gray, the sides light gray, and the underside pale gray or white. There is also a dark band that runs from the eye to the flipper, bordered above by a thin light line. However, the spinner dolphin has more geographic variation in form and coloration than other cetaceans. In the open waters of eastern Pacific, dolphins have relatively small skulls with short rostra. There is also a dwarf form of spinner dolphin that occurs around southeast Asia. In these same subspecies, a dark dorsal cape dims their tripartite color patterns. Further offshore, subspecies tend to have a paler and less far-reaching cape. In certain subspecies, some males may have upright fins that slant forward. Some populations of spinner dolphin found in the eastern Pacific have bizarre backwards facing dorsal fins, and males with strange humps and upturned caudal flukes.
The spinner dolphin lives in nearly all tropical and subtropical waters between 40°N and 40°S. The species is primarily inhabit inshore waters, islands or banks. However, in the eastern tropical Pacific, dolphins live far from shore. Spinner dolphin may use different habitats depending on the season.
The spinner dolphin feed mainly on small mesopelagic fish, squids, and sergestid shrimps and will dive 200-300 m to feed on them. Spinner dolphins of Hawaii are nocturnal feeder and forage in deep scattering layers, which contain many species. The dwarf spinner dolphin may eat mostly on benthic fish in reefs and shallow water.