Quick answer
The sea otter is a marine mammal of the North Pacific coast and the smallest marine mammal, famous for floating on its back, using rocks as tools to crack open shellfish, and holding hands while resting. It has the densest fur of any animal, with up to a million hairs per square inch, and is a keystone species that keeps kelp forests healthy. Sea otters typically live 10 to 20 years.
Key takeaway
The sea otter is a marine mammal of the North Pacific coast and the smallest marine mammal, famous for floating on its back, using rocks as tools to crack open shellfish, and holding hands while resting. It has the densest fur of any animal, with up to a million hairs per square inch, and is a keystone species that keeps kelp forests healthy. Sea otters typically live 10 to 20 years.
Sea Otter overview
Sea Otter (Enhydra lutris) is a mammal listed here as Endangered. Typical weight 14–45 kg (31–99 lb); lifespan around 10–20 years.
Sea Otter ecology
Diet: Carnivore. Habitat: Coastal North Pacific and kelp forests. Movement and social systems reflect those pressures across the native range.
Sea Otters and people
Learn before you travel or keep related pets. Wild sea otters are not toys; captive care needs species-specific husbandry.
Status and further reading
Conservation label in our guides: Endangered. See the full Sea Otter profile for taxonomy, FAQs, and related topic guides on this site.
The warmest coat in nature
Unlike whales and seals, sea otters have no insulating blubber. Instead they rely on the densest fur of any animal, with up to a million hairs per square inch, trapping a layer of air to stay warm in cold seas. They spend hours grooming to keep this fur clean and waterproof.
Tool users
Sea otters are one of the few animals that use tools. They often carry a favorite rock in a loose pouch of skin under the forearm and use it to smash open hard-shelled prey such as clams, mussels, and sea urchins while floating on their backs.
Sources
Sea Otter FAQs
What are key facts about sea otters?
The sea otter is a marine mammal of the North Pacific coast and the smallest marine mammal, famous for floating on its back, using rocks as tools to crack open shellfish, and holding hands while resting. It has the densest fur of any animal, with up to a million hairs per square inch, and is a keystone species that keeps kelp forests healthy. Sea otters typically live 10 to 20 years.
What is the scientific name of the sea otter?
Enhydra lutris — used in research and conservation listings for sea otters.
What do sea otters eat?
Sea Otters are described as carnivores, with seasonal and regional variation in Coastal North Pacific and kelp forests.
Where do sea otters live?
They are associated with Coastal North Pacific and kelp forests. Local presence depends on food, cover, and human land use.
What is the conservation status of sea otters?
Listed in our guides as Endangered. Check the IUCN Red List and national assessments for the latest formal category.