Sea Otter
Enhydra lutris

(Linnaeus, 1758)

Range Canada, Japan, Mexico, Russia, United States
Estimated Population Decreasing
Scientific Classification
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Mustelidae
Genus Enhydra

(Fleming, 1828)

Species • E. lutris
Conservation Status
(IUCN 3.1)

The Sea Otter is an otter than lives in marine waters only.  This otter is very popular in aquariums. It can be found in many waters around America. The relatives of the otter includes weasels, skunks, river otters; Family: Mustelidea (sea otters are the only exclusively marine member of this family).

Adult sea otters typically weigh between 14 and 45 kg (31 and 99 lb), 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.

Sea otter

The sea otter inhabits offshore environments, where it dives to the sea floor to forage. It preys mostly on marine invertebrates such as sea urchins, various molluscs and crustaceans, and some species of fish. Its foraging and eating habits are noteworthy in several respects. First, its use of rocks to dislodge prey and to open shells makes it one of the few mammal species to use tools. Other diets include crabs, snails, urchins, clams, mussels and other invertebrates.

In most of its range, it is a keystone species, controlling sea urchin populations which would otherwise inflict extensive damage to kelp forest ecosystems. Its diet includes prey species that are also valued by humans as food, leading to conflicts between sea otters and fisheries.

Sea otters, whose numbers were once estimated at 150,000–300,000, were hunted extensively for their fur between 1741 and 1911, and the world population fell to 1,000–2,000 individuals living in a fraction of their historic range. A subsequent international ban on hunting, conservation efforts, and reintroduction programs into previously populated areas have contributed to numbers rebounding, and the species now occupies about two-thirds of its former range.

The recovery of the sea otter is considered an important success in marine conservation, although populations in the Aleutian Islands and California have recently declined or have plateaued at depressed levels. For these reasons, the sea otter remains classified as an endangered species.

Endangered01-sea-otter 24051 600x450

Interesting FactsEdit

  • An otter may hunt on the seafloor, but always returns to the surface to eat. Floating there on its back, it uses its chest as a table. (And if dinner’s a crab or clam, the otter may use a rock to crack open its prey.)
  • To help it stay warm in cold water, a sea otter burns calories at nearly three times the rate you do. An otter fuels its fast metabolism by eating up to a quarter of its weight in food a day. (A 150-pound person would have to eat 35-40 pounds of food a day to match that!)
  • An otter’s coat has pockets—flaps of skin under each front leg. An otter uses them to stash prey during a dive, which leaves its paws free to hunt some more.

Monterey Bay Animal Details



Nellie the Sea Otter stacks cups at Point Defiance Zoo & Aquarium

Nellie the Sea Otter stacks cups at Point Defiance Zoo & Aquarium

Marine Marine HabitatsAquariumsGlobal OceansOcean Weather
Vertebrate FishesMammalsReptilesAmphibiansCartilaginous FishesSharks
Invertebrate ArthropodMolluscaEchinodermsCnidaria
Conservation Status Critically EndangeredEndangeredNear ThreatenedVulnerableLeast ConcernData DeficientNot Evaluated