Family: Phocoenidae, Porpoises view all from this family

Description To 7' (2.1 m). Extremely robust; head and flukes small. Shiny black overall, sides with large, conspicuous, oval, white patch, sometimes with faint dark spots beginning well below dorsal fin and meeting at midriff; some individuals entirely black; dorsal fin usually white above, black below. Wide variation in pigmentation. Forehead slopes steeply to short, poorly defined beak; mouth small, narrow. Dorsal fin triangular, base long. Tail has pronounced keel above and below.

Similar Species Pacific White-sided Dolphin (Lagenorhynchus obliquidens) has abbreviated dark beak. Harbor Porpoise (Phocoena phocoena) has coloring mainly in subdued shades of brown and gray.

Habitat Often well offshore and beyond outer edge of continental shelf, but also in deeper inshore waters.

Range From Pribilof Islands, possibly Bering Strait, to Baja California.

Discussion Dall's Porpoises, also known as True's Porpoises and Spray Porpoises, are usually seen in small herds of 20 or less. They are extremely fast swimmers, sometimes moving through the water so rapidly that they throw up a plume of water like the "rooster tail" of a racing hydroplane. They may ride bow waves. This species feeds on squids, crustaceans, and deep-sea fishes. Its known predators include the Killer Whale and sharks. Many are harpooned intentionally by Japanese fishermen in the northern Pacific; some are killed by drifting into salmon nets.