Types of Otters

Otters' elongated, streamlined bodies make them powerful swimmers.Oriental Short-clawed Otter image by Daniel Mortell from Fotolia.com

Otters are mustelids, belonging to the same group of animals as skunks, wolverines and weasels. Otters share certain traits, such as a streamlined body, strong tail and webbed feet, that enable them to be powerful and agile swimmers. Otters are at home in the water, with some species spending the majority of their time in rivers, lakes and the ocean. Two types of otters live in North America, with a greater variety in other parts of the world.

Giant River Otter

The giant river otters that live in the La Plata, Amazon and Orinoco River systems in South America are the largest of all otters. Some attain lengths of 6 feet and weigh close to 75 pounds. These otters possess the water-repellent coats common to all otters and can close their ears and nostrils when submerged in water. The giant otter, according to the National Geographic website, can consume from six to nine pounds of fish per day, with creatures such as snakes and crayfish also on their menus. River otters live in groups and the animals will defend their territory from invaders. The giant river otter suffered greatly from trapping and hunting, reducing its range from over most of South America to its present state, with the population estimated to be a few thousand.

No otter in the world has the geographic distribution as wide-ranging as the Eurasian otter. This medium-sized otter, which averages between 15 and 20 pounds, lives in areas ranging from Europe's Atlantic coastal region to Russia's Pacific Coast, northern Africa and Asia. The Eurasian otter is the most independent and solitary of the otters, with the males having a large territory to patrol that does not include other males, although it may include some females. The Eurasian otters typically forage for food at night.

The northern river otter of North America will stay active during the day if humans do not disrupt its schedule. This otter lives in streams, rivers and other bodies of water in forested regions of the continent. The northern river otter is at home in the water, raising its head slightly as it treads water to view its surroundings, according to the "National Audubon Society Field Guide to Mammals." The northern river otter amuses itself when alone or in groups. These otters engage in activities such as body surfing in the current of streams and rivers or sliding down muddy trails into the water.

The sea otter is the heaviest member of the weasel family, with some weighing as much as 100 pounds. These marine mammals have what the Defenders of Wildlife website describes as the densest fur of all animals, which makes up for their lack of the fat layer most marine mammals have to keep warm. Sea otters spend much of their times in shallow coastal waters of the Pacific, from California to Alaska and off Siberia and Japan. The sea otter subsists on sea life such as urchins, clams and crabs, acquired by diving to distances as deep as 330 feet beneath the surface.