The bowhead whale has the thickest blubber of any animal, reaching about 50 centimetres.
Bowhead whales are specialized for life in icy Arctic waters. Their blubber can be roughly half a metre thick, providing powerful insulation against water that remains near its freezing point. This layer also stores energy for long migrations and periods when feeding conditions change.
The bowhead’s adaptations extend beyond blubber. Its massive skull can break through relatively thin sea ice, and its enormous, arched mouth contains baleen plates for filtering small prey such as copepods and krill. Unlike many other whales, bowheads lack a dorsal fin, an advantage when moving beneath ice.
Bowhead whales are among the longest-lived mammals. Some individuals may survive for more than 200 years, based on age estimates from eye tissues and recovered historical harpoon points. They were heavily hunted commercially from the seventeenth through nineteenth centuries, but several populations now receive legal protection. The species is restricted mainly to Arctic and sub-Arctic waters.