The
sea otter (
Enhydra lutris) is a
marine mammal native to the coasts of the northern and eastern
North Pacific Ocean. Adult sea
otters typically weigh between , making them the heaviest members of the
weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of
fur, the densest in the animal kingdom. Although it can walk on land, the sea otter lives mostly in the ocean.