Physical Description
The unique body shape of Dall's porpoise makes it easily distinguishable from other cetacean species. The animal has a very thick body and a small head. The colouration is rather like that of a killer whale; the main body of the porpoise is very dark grey to black creeper, with very demarcated white patches on the flank and belly. The dorsal fin is set just back from the middle of the back and sits up erect. The upper part of the dorsal fin has a white to light grey "frosting".
The fluke has a similar frosting. The adult fluke curves back towards the body of the animal, which is another distinguishing feature. It is larger than other porpoises, growing up to 2.3 m (7.5 ft) in length and weighing between 130 and 220 kg (290 and 490 lb). There is also sexual dimorphism in the species, with males being larger, having a deeper caudal peduncle and a pronounced hump behind the anus. Young Dall's have a greyish tint and dark-colored flukes.
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