The males often measure up to 48 inches and weigh 64 pounds. Females are a maximum of 48 inches and weigh 44 pounds.   Their cousins the North American River Otters tend to weigh only half as much about 30 pounds.

Thick  Fur

Sea otters have the thickest fur out of all the animals in the world. There is about 350,000 to 1,000,000 hairs of fur per square inch, compared to a dog which only have 1,000 to 60,000 hairs per square inch.  As a matter of fact, a penny placed on a sea otter’s body would cover 250,000 hairs. That’s more than the hairs on two human heads!  They have two layers of fur surrounding their body.  There is a thick layer against their skin.  Another layer of longer hair grows out of the thick fur.  They depend on their fur for warmth because they have no blubber like whales and seals.  Their fur is usually brown in color.  Sometimes the fur on their heads becomes white or golden because the sun bleaches it, like Goldie at Monterey Bay Aquarium. 

Grooming

Do you spend eight hours a day in front of a mirror combing your hair?  Well, otters spend eight hours a day grooming themselves.  But, otters don’t groom themselves just for looks. Actually they must groom themselves to stay alive.  While grooming they rub and blow air into their fur creating air pockets in between the hairs of the outer layer. This technique provides insulation which keeps them warm in the cold water.  Without blubber, their fur is essential for survival.

Feet and Tail

Otters have small paws with retractable claws on their fore limbs to help them in grooming and eating. They also have secret pouches of loose skin under their forearms.  This armpit area is used to store their tools (usually a rock) so they can have free “handsâ€? while they are eating.  It can also be used to transport food during diving. Their back feet or hind limbs have flipper-like feet which are used like flippers to aid them in swimming.  While resting, otters keep their feet up out of the water.  This helps conserve body heat because they have no fur on their feet which causes them to lose heat rapidly. Sea otters usually swim on their backs and paddle with their hind limbs. An otter’s tail is 10-14 inches long. It is flat (different than a river otter’s) to aid them in swimming.

The Senses

The sea otters have very good sight above and below the water. An otter’s lungs are bigger than any land animal of the same size. They can dive deeper because of their big lung capacity. Sea otters dive to hide from predators and to retrieve food. An otter has external ears and can hear very well. Their ears are protected by a flap of skin just inside the ear to stop water from going inside. Sea otters have a very good sense of smell. On our trip to Monterey our coach Mr.Rasner had to cleanse his shoes before being allowed by the trainers to enter the otter’s habitat area.  An unfamiliar scent could make the otters frightened or feel threatened.  They could try to hurt someone or quit eating.