White-beaked Dolphin, Lagenorhynchus albirostris

White-beaked dolphin, Lagenorhynchus albirostris.

The white-beaked dolphin, Lagenorhynchus albirostris – although not a truly "arctic" mammal – inhabits the pelagic zone in offshore waters of the eastern Arctic. Its name, albirostris, means "white snout" and refers to its distinctive, short, white beak. However, this is imprecise since the colour of the beak can vary from pale yellow to dark grey to mottled brown.

White-beaked dolphins have a thick layer of blubber to support their life in cold arctic waters, where they feed largely on squid, hermit crabs, and fish. These dolphins are powerful, fast swimmers that travel in groups ranging from 10 to 1500 individuals. At an average length of 2.5–2.8 m, white-beaked dolphins are not much longer than a typical human male; yet, they weigh between 180 and 275 kg!