Sea otters A mother sea otter (Enhydra lutris) with her pup in the icy waters of Prince William Sound, Alaska. (more) How Do Sea Otters Stay Warm? Written by Kai Shanebeck Kai (he/they) is an ecologist and parasitologist who studies the parasites of aquatic mammals (otters, seals, mink) as well as vector-borne and zoonotic disease dynamics. Kai Shanebeck Fact-checked by Britannica Editors Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Britannica Editors Last updated Apr. 8, 2026 •History Sea ottersA mother sea otter (Enhydra lutris) with her pup in the icy waters of Prince William Sound, Alaska.© Gerald Corsi—E+/Getty Images Sea otters (Enhydra lutris) are the only fully aquatic otter species, inhabiting some of the coldest coastal waters on Earth. They are also the smallest marine mammals, typically spending their entire lives in seas that would quickly chill most other mammals to the core. Yet, unlike such marine mammals as whales and...

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