Northern right whale dolphin

The northern right whale dolphin (Lissodelphis borealis) is a small, slender dolphin of the cold and temperate waters of the North Pacific Ocean. It lacks a dorsal fin, which gives it a superficially porpoise-like look, and has a streamlined, nearly all black body with a narrow white ventral band that widens at the throat. Adults are 2 to 3 metres long and weigh 60 to 100 kilograms, with females smaller than males. It typically lives offshore between 34 and 55 degrees north in water of 8 to 24 degrees Celsius, travelling in pods of up to 110 animals in the eastern North Pacific and 200 in the western North Pacific, and sometimes in far larger groups. It is a fast swimmer that averages about 26 kilometres an hour and dives to about 200 metres for lanternfish, squid, Pacific hake and saury. Unlike most oceanic dolphins it makes clicks and burst pulses rather than whistles, and its encephalization quotient of 5.55 is the highest of any living species except humans.