Range:

Africa, Asia, and parts of North America, Central America, and South America

Habitat:

Sea otters in Pacific Ocean and along coastline, but most otter species live in rivers, lakes, and marshes

Champion swimmers

Otters are the only serious swimmers in the weasel family. They spend most of their lives in the water, and they are made for it! Their sleek, streamlined bodies are perfect for diving and swimming. Otters also have long, slightly flattened tails that move sideways to propel them through the water while their back feet act like rudders to steer.

Almost all otters have webbed feet, some more webbed than others, and they can close off their ears and nose as they swim underwater. They can stay submerged for about five minutes, because their heart rate slows, and they use less oxygen. They’re also good at floating on the water’s surface, because air trapped in their fur makes them more buoyant.

Sticky fur

Have you ever noticed that when otters come out of the water, their outer fur sticks together in wet spikes, while the fur underneath still seems dry? That’s because otters have two layers of fur: a dense undercoat that traps air; and a topcoat of long, waterproof guard hairs. Keeping their fur in good condition is important, so otters spend a lot of time grooming. In fact, if their fur becomes matted with something like oil, it can damage their ability to hunt for food and stay warm.

You can tell otter species apart by the shape and amount of fur on their nose.
Unlike other marine mammals, sea otters do not have a layer of blubber to keep them warm; they rely on warm air trapped in their fur.
Sea otters have the densest fur of any mammal, with about 100,000 hairs in a space about the size of a postage stamp.
Most otter species capture prey with their mouths, but Asian small-clawed otters and sea otters have flexible fingers and grab with their hands.
North American and European river otters have been known to share dens with beavers—but the beavers do all the building,

The San Diego Zoo currently has a Cape clawless otter, a Pacific otter, and spotted-necked otters.

Four otter species, including the sea otter Enhydra lutris, are endangered; three otter species are vulnerable.