Spinner dolphins (Stenella longirostris) swimming in a school. These social animals are found in tropical and subtropical waters worldwide. They are usually found in schools of approximately 200 individuals. They are small dolphins, not exceeding 2 metres in length, or 75 kilograms in weight. They feed at night, on small fish and squid. Spinner dolphins are named for their lengthways spinning jumps, which are performed most frequently at night. Photographed in the Red Sea, Egypt.