Dall's Porpoise

Dall's porpoise (Phocoenoides dalli) is the largest of the porpoises and the only member of its genus. It lives only in the North Pacific, from California north to the Bering Sea and Okhotsk Sea and down to the Sea of Japan, and it generally prefers cold water. The species is named for the American naturalist W. H. Dall. Adults grow up to 2.3 metres long and weigh 130 to 220 kg, with a wide, robust body, a comparatively tiny head and mostly black colouring broken by white patches on the flank and belly. Two colour forms, the dalli type and the truei type, are recognised as subspecies. Dall's porpoises are fast swimmers whose surfacing throws up a spray called a rooster tail, and they often ride the bow waves of boats. They hunt mesopelagic fish such as myctophids and gonatid squid. Abundance is estimated at over one million animals and the IUCN lists the species as Least Concern, although driftnet bycatch and a continuing hunt for meat in Japan remain concerns.