Scientific name: Family Mustelidae


OtterOtters have very sleek and streamlined bodies which are good for diving and swimming as they spend most of their time in the water. They also have long quite flat tails that move sideways to help them propel through the water, and they use their back feet to steer themselves. Almost all species of otters have webbed feet, and they can close off their ears and noses when they swim underwater. Otters can slow down their heart rate so that they use less oxygen, this means that they can stay underwater for about 5 minutes at a time.

Unlike most marine animals otters don’t have blubber so they have to rely on their fur to keep them warm. Otters have two layers of fur – a topcoat of waterproof guard hairs which are quite long and a undercoat that is thick and traps air which helps to keep the otters warm. Otters spend a lot of time grooming their fur because if it gets matted with oil etc it means they might not be able to hunt properly or to keep themselves warm.

There are 13 species of otters and the largest the giant otter can measure up to 2.4 metres (7.8 feet) long while the smallest otter the asian small-clawed otter measures about 0.9 metres (3 feet) long. The heaviest species is the sea otter with the males weighing up to 43 kilograms (95 pounds) and the lightest the asian small-clawed otter weighs about 5 kilograms (11 pounds).


The lifespan of the otter is about 15 -20 years and up to 25 years in captivity.


For most otters fish is the main part of their diet. River otters eat mostly fish but also crabs, crayfish, frogs and occasionally a small mammal or bird. The sea otter eats many of the same things but also sea urchins, abalone and clams which they crack open on rocks which they hold on their stomachs.

River otters use lots of energy and have a high metabolism so they have to eat several times a day. Sea otters also have a high metabolism and because of their lack of blubber they have to eat about 25% of their body weight in food each day.


Otters are found mainly in Africa, Asia, Central America, South America and parts of North America

Sea otters are found in the Pacific Ocean and along the coastline, but most otter species are found in rivers, lakes and swamps and they are equally at home on land or water.


Otters reach sexual maturity between 2 to 5 years. The female otter will usually have between 1 and 6 pups depending on the species. The gestation period for the smaller otters is about 2 months. For most otters (not the sea otter) the pups are born in a den with their eyes closed and they are helpless. The mother takes care of the pups and they open their eyes and start exploring after about one month, at roughly two months they start swimming, and they stay with their mother and brothers and sisters until they are about 1 year old.

For the sea otters it is different because their habitat is the ocean. Sea otter pups are born with their eyes open, and even though they are not able to swim they have a coat of hair that lets them float. Their mother carries them on her stomach for the first two months until they are ready to start swimming and diving on their own.

Social Life

Some species of otters live solitary lives but other species live in extended family groups. These groups are usually made up of a mother, her new pups, plus the otters she has had previously, the males tend to live with a few other males or spend most of their time alone.

Otters are extremely energetic and they really seem to like to play. They like to be busy most of the time either hunting or playing, they like to throw things, wrestle, chase their tails or chase each other. River otters like to slide down the banks of the river into the water and they will do it over and over again. Otters make lots of different sounds from screaming to growling. All of this playfulness is part of thier courtship, communication and bonding.

Quick facts

Different from other marine animals sea otters do not have blubber to keep them warm and have to rely on their fur.

Otters have a very high metabolism and have to eat a lot of food per day, or eat several times a day.

They are very playful creatures and are intelligent and very curious.