Scientific classification: Seals are classified in the suborder Pinnipedia of the large mammalian order, Carnivora. The true seals make up the family Phocidae, and the harbor seal is classified as Phoca vitulina.
Introduction
Seals are large aquatic mammals distinguished by having all four legs fully adapted into flippers. There are three families of seals: the true seals, the eared seals, and the walrus. True seals lack external ears and have relatively short flippers that are nearly useless for walking on land. The eared seals, including the sea lions and fur seals, sport tiny external ears and can lift their bodies off the ground with their flippers. The stout-bodied walrus, species of seals with its wrinkled skin and unique tusks, is the only member of its family.
Physical description
Although similar in appearance, it is easy to distinguish differences between eared seals (sea lions and fur seals), true seals, and walruses. Sea lions and fur seals have tiny external ears while only the ear openings are visible in true seals and walruses. On land, sea lions, fur seals, and walruses rotate their large flippers back and forth to function as legs, enabling them to walk clumsily on land or ice. The short flippers of true seals do not turn under the body to act as legs. These seals move on land mainly by flexing their bodies, although on snow and ice they can also use their foreflippers as paddles to reach surprising speeds, species of seals.
Habitat
Most seals live in cold waters near the Arctic and Antarctic. Some true seals live under ice for much of the year, finding cracks between ice floes or scattered holes in order to breath. Depending on the species, true seals use strong claws, teeth, or their head to break through new ice that freezes over openings. A few kinds of true seals are found in warmer regions. In North American waters, harbor seals are found from northern Canada to Georgia on the Atlantic coast although they are not common south of Massachusetts and from Alaska to Baja, Mexico, on the Pacific coast. The northern elephant seal remains in strictly ice-free waters. Its range is from Vancouver Island, Canada, to Cedros Island, species of seals, off Baja, Mexico.
Endangered Seals
Natural predators of seals include large sharks, especially the great white shark, the orca, or killer whale, and other seals such as the leopard seal. Polar bears kill seals on land and ice in the Arctic. There are even reports of eagle attacks on baby Caspian seals. Perhaps the greatest menace to seals are humans, who have long hunted seals for food and seal skins, used for clothing and even housing and small boats. Commercial sealing developed into a profitable business in Europe and colonial America by the 1700s. Like whales, species of seals, seals were hunted for their blubber, which was converted to oil for fuel, lubrication, and tanning. Fur seals were especially valued for their luxuriant pelts. Today seals are still killed for their skins in some countries, such as Canada and Russia.