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Sea Otter Anatomy



An endangered species, the adult sea otter is the smallest of the marine mammals. It’s a member of the weasel family, and the only marine mammal that doesn’t have blubber to keep it warm. Instead the sea otter relies on its thick fur to keep its body temperature around 100 degrees.

Sea otters have two layers of incredibly dense fur, more than a million fibers per square inch. Outer guard hairs are around 1 1/3 inches long and when properly groomed lay flat against the body.

Underneath the guard hair is another layer of fur that stays completely dry. The sea otter’s forepaws are very agile. They can rub, twist, and pull with a great amount of strength. The forepaws have retractable claws. The palms have tough pads that help with gripping.

Under each forearm are baggy pockets of loose skin. The sea otter uses these pockets to store food it has gathered. It also stores favorite rocks that it uses for cracking open mollusks and clams.

The forelegs are webbed and look sort of like flippers. The last digit is the longest, which makes swimming on its back easy, but walking on land awkward. The sea otter’s tail is very muscular, helping with steering and swimming. Sea urchins and crabs are easily cracked open with the four incisors on the sea otter’s lower jaw.

Molars are flattened and rounded used more for crushing food rather then cutting it.  Sea otters have good eyesight, above and below the water. The nostrils and ears close when underwater. Sea otters have a good sense of smell and can hear very well. Whiskers sense vibrations in the water. This comes in handy when hunting for prey.

The sea otter has a very buoyant body. This is due to all the air trapped in its fur, and also to its large lung capacity, two and a half times greater than other animals its size.

The sea otter can hold its breath up to five minutes underwater. All these parts working together make the sea otter one furry fantastic creature.