Walrus, a large, seal-like marine mammal that lives chiefly north of the Arctic Circle. A bull (male) walrus may grow 11 feet (3.4 m) long and weigh 3,000 pounds (1,360 kg). Walruses are protected from cold by a thick layer of fat called blubber and by a thick, wrinkled, almost hairless, tan skin.

Both male and female walruses have vibrissae, sensitive whiskers that they use to locate food along the ocean floor. The vibrissae grow to 6 inches (15 cm) in length, but are constantly being worn down. Walruses feed on mollusks, worms, crabs, and shrimp. The canine teeth of both sexes form long ivory tusks that extend downward from the upper jaw. A tusk is usually 10 to 15 inches (25 to 38 cm) long, but may grow to 40 inches (1 m) and weigh 12 pounds (5.4 kg). The walrus uses its tusks to haul itself onto ice floes, to cut through ice, and as weapons against predators. In addition, the male uses its tusks to fight other males; the male with the largest tusks is usually the leader of its herd.

WalrusesWalruses are the only seals with tusks.

Walruses have pharyngeal, or throat, pouches, which they can inflate to keep afloat while sleeping in the water. The pouches also serve as resonance chambers, allowing underwater communication.

During most of the year, males (bulls) and females (cows) live in different herds. During the breeding season, they gather on ice floes and rocky shores; the female typically bears one calf. A walrus lives for about 40 years.

Walruses are the prey of killer whales and polar bears. They are important to Eskimos who follow the traditional way of life; they eat walrus flesh and blubber and use the blubber oil for fuel. They use the hide as roofing, to make harnesses, and for other purposes. They carve decorative objects from the tusks.

The Atlantic walrus is found as far south as Labrador. It is hunted for its ivory, and its population is declining. The Pacific walrus lives in the region from the Bering Sea northward. Its population is thriving.

The walrus forelimbThe walrus forelimb is specially adapted for swimming.