Identification guide 05 species

Sea Lions, Seals, Fur Seals, and Walruses

"Is that a sea lion or a seal?" may be the question asked most often at aquariums. Pinnipeds — marine mammals with flipper-like limbs — fall into three families you can separate by their ears and the way they use their hind flippers.

Identification steps

4 steps

  1. 1

    Start with the ear flaps

    If there are external ear flaps, however small, it is an eared seal (Otariidae: sea lions and fur seals). Only an ear opening with no flap means a true seal (Phocidae). Huge tusks mean a Walrus.

  2. 2

    Check how the hind flippers are used

    Eared seals can rotate their hind flippers forward to walk on all fours and raise the upper body. True seals keep their hind flippers stretched out behind and inch along on land like a caterpillar.

  3. 3

    Telling the eared seals apart

    Large (males approach a ton), stocky, and with a low roar: Steller Sea Lion. Dark brown all over with a thick, fluffy coat and a pointed snout: Northern Fur Seal. Medium-sized, the star of shows, with a high-pitched bark: California Sea Lion.

  4. 4

    Finish with the seal and the Walrus

    Gray with black spots, stocky, and crawling on land: Spotted Seal. Weighing over a ton, with long tusks and a deeply wrinkled body: Walrus.

Eared seals (Otariidae) — have ear flaps and can walk on all fours

3 species

California Sea Lion
Photo: Rhododendrites / CC BY-SA 4.0 / Source / cropped

Identification specimen california-sea-lion

California Sea Lionカリフォルニアアシカ

Zalophus californianusLC— Least Concern

Size
About 1.8–2.4 m
Key features
The star of aquarium shows. Dark brown all over; males develop a raised forehead. Barks in a loud, high-pitched voice and performs tricks with agility. Has external ears and can walk on all fours.
Habitat
West coast of North America to the Galápagos

Where to see this species

Toba AquariumOsaka Aquarium KaiyukanIshikawa Doubutsuen22 more
California Sea Lion species profile
Steller Sea Lion
Photo: Early T, U.S. Fish and Wildlife Service / Public domain / Source / cropped

Identification specimen steller-sea-lion

Steller Sea Lionトド

Eumetopias jubatusNT— Near Threatened

Size
About 2.5–3.3 m
Key features
The largest of the eared seals. Males can weigh close to a ton, with a mane of coarse hair around the neck and a low roar. Lives in northern seas.
Habitat
North Pacific, Sea of Okhotsk, and northern Sea of Japan

Where to see this species

Otaru AquariumKamogawa Sea WorldAquamarine Fukushima4 more
Steller Sea Lion species profile
Northern Fur Seal
Photo: U.S. Fish and Wildlife Service / Public domain / Source / cropped

Identification specimen northern-fur-seal

Northern Fur Sealキタオットセイ

Callorhinus ursinusVU— Vulnerable

Size
About 1.4–2.1 m
Key features
Look for the dense, luxuriant coat covering the whole body, a pointed snout, and large hind flippers. A smaller face and fluffier look than a sea lion.
Habitat
North Pacific and Bering Sea

Where to see this species

Aquamarine FukushimaShiritsu Tamanokaiyou HakubutsukanAQUARIUM ASAMUSHI
Northern Fur Seal species profile

True seals (Phocidae) — no ear flaps; crawl on land

1 species

Walrus (Odobenidae) — long tusks

1 species

Walrus
Photo: Captain Budd Christman, NOAA Corps / Public domain / Source / cropped

Identification specimen walrus

Walrusセイウチ

Odobenus rosmarusVU— Vulnerable

Size
About 2.5–3.5 m
Key features
Long tusks and a thick, deeply wrinkled body. Weighs over a ton and uses its whiskers to find shellfish on the seabed. A large species and the only pinniped with tusks.
Habitat
Around the Arctic Ocean

Where to see this species

Otaru AquariumKamogawa Sea WorldYokohama Hakkeijima Sea Paradise5 more
Walrus species profile

Compare similar species

2 pairs

Sea lion vs seal

The most frequently asked question at aquariums. The ears and the way they move settle it instantly.

California Sea Lion California Sea Lion Spotted Seal Spotted Seal
FeatureCalifornia Sea LionSpotted Seal
Ear flaps (external ears) Has ear flaps that stick out, however small Only an ear opening, no flap
Movement on land Rotates the hind flippers forward, walks on all fours, and raises the upper body Hind flippers stay stretched out behind; inches along like a caterpillar
Front flippers Large; can prop the body up Small, with claws
At the aquarium Performs tricks in shows Swims in the pool and lounges on the rocks

California Sea Lion, Steller Sea Lion, and Northern Fur Seal

Three species in the same eared-seal family. Told apart by size, coat, and snout.

California Sea Lion California Sea Lion Steller Sea Lion Steller Sea Lion Northern Fur Seal Northern Fur Seal
FeatureCalifornia Sea LionSteller Sea LionNorthern Fur Seal
Size Males about 2.4 m Males about 3 m and close to a ton (largest) Males about 2.1 m (small)
Coat and appearance Short hair, dark brown Mane of coarse hair on the neck; light yellowish brown Dense, fluffy coat; pointed snout
Range West coast of North America to the Galápagos North Pacific and Sea of Okhotsk North Pacific and Bering Sea

Books & gear

Sources

Guide sources: ja.wikipedia.org en.wikipedia.org / Photos: see the Commons credit links beside each image.