Sea Otters Pictures, Stock Photos, Images, Illustrations

The sea otter, one of the cutest and most photogenic of marine mammals, is a sea-going member of the weasel family. It's notable for its thick coat of fur, its ability to use tools, and for its having come back from the brink of extinction in the 20th century.

Sea otters are members of the Mustelidae family, which includes weasels, badgers and otters. All species of otter are grouped in a subfamily called Lutrinae.

Like fresh-water otters, the sea otter has a long, slender body with short legs and a long, thick tail. Its hind legs, which are webbed for swimming, are longer than its forelegs. It has retractable front claws, used for catching and grasping food. Unusual for mustelidae, it lacks anal scent glands. Its face and head are round when compared to the pointed face of weasels.

Sea otters are the second smallest marine mammal, after marine otters, Lontra felina, the smallest. They weigh between 14 (31 lbs) and 45 kg (99 lbs) when fully grown, and have a length of 1 to 1.5 meters. Males are larger and heavier than females.

Sea otters have a thick coat of brown fur made up of a fine, dense inner coat and a thicker overcoat. The undercoat has a density of up to 400,000 hairs per square centimeter, and its function is to trap warm air close to the otter's body. The overcoat is waterproof, keeping cold sea water separate from the pockets of warm air that insulate the animal. This system allows sea otters to function in the cold Pacific Ocean, despite their lack of blubber, the insulator of seals and whales.

The diet of sea otters is sea urchins, shellfish, crabs, squid, octopus and fish. The otters procure this food in dives of from 1 to 4 minutes. After catching its food, it surfaces and floats on its back to eat. It has been observed opening shellfish with the help of rocks, a behavior which puts it in an elite group of tool-using animals.

Sea otters have a high metabolic rate, so they must forage constantly and eat up to 30% of their body weight each day.

Sea otters give birth in the ocean to one or occasionally two pups in a breeding season. If two are born, only one is likely to survive. The air pockets of the pup's fur make it so buoyant that it cannot dive. It floats around on the surface while the mother dives for food. The constant bleating of the pup allows the mother to find it when she resurfaces.

When the pup is ready, the mother teaches it how to dive and hunt for food and how to groom itself. Pups depend on their mothers for survival for an average of 6 months. Only 30% of sea otter pups survive their first year. The best predictor of survival is the pup-care experience level of the mother. Sea otters live an average of 11 years in the wild, but may survive up to 23 years with a good share of luck and survival skill.

The range of sea otters is a long arc around the Northern Pacific, going from northern Japan, to the Kuril Islands and Kamchatka, to Alaska, down the Western coast of America as far south as Mexico on the Baja Peninsula.

Predators of the sea otter are man, orcas, sharks, and eagles, the latter of which pluck the pups from the ocean surface as they wait for their mother to return from foraging. Man is the sea otter's most dangerous enemy, however, having caused the near extinction of the animal. Due to over-hunting for the fur trade, less than 2,000 sea otters remained in existence by 1911. Thanks to extraordinary conservation efforts, they now number between 100,000 and 150,000 worldwide.

The IUCN lists sea otters as Endangered. Sea otters are particularly susceptible to environmental degradation, especially crude oil spills. Oil coats the otter's fur, preventing it from trapping air, so the otter dies from cold.

Taxonomists are not in agreement on Sea Otter taxonomy. Depending on the source, there are up to three subspecies, the Asian sea otter (Enhydra lutris gracilis or Enhydra lutris lutris) in Japan and Russia, the Northern sea otter (Enhydra lutris kenyoni or Enhydra lutris lutris) in Alaska and Canada, and the Southern sea otter (Enhydra lutris nereis) in California and Mexico.

© Sea Otter, Enhydra lutris, information assembled from published and on-line sources by Kevin Miler for SeaPics.com. Dec. 21, 2007.

Sources:

http://en.wikipedia.org/wiki/Sea_otters

http://lioncrusher.com/animal.asp?animal=164