Classification: Gray classified Stenella longirostris in 1828 - the specific name referring to this species' long snout. There are no subspecies, but there are four distinct Eastern Pacific forms: the Eastern, the Whitebelly, the Costa Rican and the Hawaiian.
Description: The Spinner Dolphin is a slender creature with a long, thin beak to which the distinct forehead slopes gently. The dorsal varies with both age and geographical form; it can lean forward, be curved, or be completely triangular in shape. The flippers are long and pointed, and a a stripe links it to the eyes. Eastern Pacific and Costa Rican animals are mainly grey, with other forms usually two- or three-tone. Both the Hawaiian and Whitebelly forms have a dark grey or black dorsal cape, paler flanks and sides, and a creamy-white belly. All forms measure between 1.3 and 2.1m in length, and weigh between 45-75kg.
Recognition at sea: The Eastern and Costa Rican forms of this species are unmistakable, with their triangular fins and uniform grey colour. Other Spinners, the two- and three-tone forms, can be identified by the shape of the dark area on the dorsal cape and the long blac-tipped snout. Spinning in the air is characteristic of this species.
Habitat: The Spinner Dolphin occupies both offshore and inshore waters.
Food & Feeding: This species takes midwater fish and squid, and is different from other dolphins in that it feeds by night.
Behaviour: Units range from a few animals to a few thousand, often mixing with other cetacean species such as Pilot Whales and Spotted Dolphins. Spinner Dolphins are dramatically acrobatic, with somersaults, high spinning leaps and other aerial movements popular. They vocalise with whistles and clicks, and can travel as fast as 20kph.
Estimated Current Population: Unknown.
The Influence of Man: Spinner Dolphins are often targeted
in the purse-seine and yellowfin tuna fisheries of the eastern Pacific Ocean.
Elsewhere, many of these dolphins are accidentally killed in gillnets, and
also taken in harpoon fisheries. Some individuals have been kept successfully
in captivity for at least 10 years.