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Sea otter

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The sea otter is a special marine mammal found in the North Pacific Ocean.

Seaotterrocks
Seaotterrocks

While it can walk on land, it can live its entire life in the water. These animals are the heaviest members of the weasel family, known as mustelids.

Enhydra lutris skull - MUSE
Enhydra lutris skull - MUSE

They are also among the smallest marine mammals in the world. Sea otters are very important to their homes in the ocean. They are a keystone species, which means they help keep the whole environment healthy. By eating sea urchins, they stop those creatures from destroying huge kelp forests.

Kelp-forest-Monterey
Kelp-forest-Monterey

Staying warm in cold water is a big job for a sea otter. Most marine mammals use a thick layer of fat called blubber to stay warm. Sea otters do not have blubber. Instead, they have the densest fur in the animal kingdom.

Sea otter cleaning
Sea otter cleaning

Their coat has long guard hairs and short underfur. The guard hairs stay waterproof to keep the underfur dry. This creates a layer of trapped air between the fur and the skin. This air layer acts like a warm blanket to keep the otter's body heat in. Because the fur must be clean to work, otters spend a lot of time grooming.

Sea otters holding hands, cropped
Sea otters holding hands, cropped

Sea otters are also very clever when it comes to finding food. They dive to the sea floor to look for marine invertebrates. This includes things like sea urchins, mollusks, and crustaceans.

sea otter with sea urchin
sea otter with sea urchin

They are one of the few mammal species that use tools. An otter will often use a rock to smash open a shell. This helps them reach the tasty food inside. They use their front paws to grip slippery prey while they eat. Their long, webbed hind feet help them swim quickly through the water.

Otter with mussels & barnacles
Otter with mussels & barnacles

History shows that sea otters have faced very hard times. Between 1741 and 1911, people hunted them extensively for their thick fur.

Sea otter hunters 1896
Sea otter hunters 1896

Their numbers dropped from as many as 300,000 down to only about 1,000 individuals. This massive loss is called a population bottleneck. This happened because so many animals were taken from the wild at once. Today, many conservation programs are working to help them grow again. They now live in about two-thirds of their old home. However, they are still listed as an endangered species.

London Sea Otter pelt sales 1871-1910
London Sea Otter pelt sales 1871-1910

Scientists have studied sea otters to learn how they changed over millions of years. Genetic analysis shows they shared an ancestor with other otters about 5 million years ago.

Sea otter nursing02
Sea otter nursing02

The sea otter lineage became isolated in the North Pacific about 2 million years ago. They are considered newcomers to the sea compared to whales or seals. Some scientists even thought they were related to seals until they studied their genes. There are three main subspecies of sea otters living in different areas. These include the Asian sea otter, the northern sea otter, and the southern sea otter. Each group lives in its own part of the Pacific coast.

CalifCentralCoast
CalifCentralCoast
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🖼️ Images & Media (16)
File:Seaotterrocks.jpg
Seaotterrocks.jpg
File:Enhydra lutris skull - MUSE.JPG
Enhydra lutris skull - MUSE.JPG
File:sea otter with sea urchin.jpg
sea otter with sea urchin.jpg
File:Sea otter cleaning.jpg
Sea otter cleaning.jpg
File:Sea otters holding hands, cropped.jpg
Sea otters holding hands, cropped.jpg
File:Sea otter with injured nose.JPG
Sea otter with injured nose.JPG
File:Sea otter nursing02.jpg
Sea otter nursing02.jpg
File:CalifCentralCoast.jpg
CalifCentralCoast.jpg
File:Sea otter kelp forest Chumash Heritage National Marine Sanctuary.PNG
Sea otter kelp forest Chumash Heritage...
File:Otter with mussels & barnacles.jpg
Otter with mussels & barnacles.jpg
File:Kelp-forest-Monterey.jpg
Kelp-forest-Monterey.jpg
File:Sea otter hunters 1896.jpg
Sea otter hunters 1896.jpg

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