:: Sea Otter Adaptation  

The sea otter has made many adaptations in order to survive better in its habitat.  First, the sea otter uses their feet to reduce or maximize heat loss when water temperatures are too hot or too cold.  When the water temperatures are too cold sea otters reduce heat loss by floating on their backs with their feet out of the water.  When the sea otter is trying to lose heat, they extend their feet out underwater to maximize their surface area.  To preserve body heat sea otters tend to spread out or fold up their feet. 

Another adaptation developed by the sea otter is how they have been shown to increase or decrease their buoyancy in response to fluctuation in water temperature.  They control their lung capacity to increase buoyancy in cold water and reduce lung volume to decrease buoyancy in warmer waters.

Picture courtesy of Michael "Mike" L. Baird, bairdphotos.com

A sea otter floating on its back with its feet out of the water.

Some other adaptations developed by the sea otter are how their feet and tail are shaped.  Sea Otter’s tails are smaller than other otters to reduce surface area.  The sea otter’s feet are webbed which are good for picking up speed in the water.  The sea otter's tail at the base is very plump and as it reaches the tip flattens, this helps the sea otter swim at a quick pace under water.  The sea otter's feet have areas of increased heat loss because of their actions during movement.  When a sea otter swims their feet move faster than the rest of their body, concluding that they suffer more heat loss.  In result sea otters have adapted heat exchangers in their feet to balance the loss.  In the sea otter’s legs their arteries are completely surrounded by veins.  This means that before the arterial blood reaches the leg skin it is cooled by the cooler veinous blood traveling back to the heart.  In conclusion, the blood entering the body is warm and the blood going to the skin is limiting heat loss.

Also the sea otter has very good eyes which allow them to see very good underwater and on land.  This is very useful because sea otters during some point in their life will be on both land and water.    Also the sea otter has a lot of insulating fur to keep warm.  Sea Otter's have roughly 850,000 to one million hairs per square inch on their body (Marine Mammal Center).  Sea Otters have two types of hair: stout guard hairs and under fur.  The stout guard hairs form a waterproof outer covering and the under fur is very dense.  This is very important because unlike other mammals sea otters do not have insulating blubber. From the mid 1700s to 1911 sea otter furs were very valuable and were sold for roughly $1,125 each (Nowak).  The sea otter population was greatly affected by this and their numbers dropped dramatically.  Since then treaties have been put into place to help protect the sea otters. (See also Interactions). Also the sea otter doesn’t get sick from drinking salt-water.  Sea Otters drink this because it helps eliminate urea from their body.

Lastly the sea otter has long whiskers growing around their muzzle to detect fish.  They can do this by detecting vibrations in the water caused by the fish’s tail.  The whiskers help the sea otters hunt in any water condition.  Also the molars of the sea otter are very different than other animals.  There molars are for crushing things and not for fish slicing and things of that nature.  All of these adaptations have helped the sea otter become comfortable in their environment.

To learn what animals the sea otter interacts click next.