 The
scientific name for the group of animals that includes seals, sea lions, and
walruses is Pinnipedia. It's a Latin word meaning "fin-footed" and refers to the
modification of limbs to flippers. Pinnipeds have four flippers - one pair in
front, and one pair in back.
Pinnipeds share five common characteristics with other mammals. They're
warm-blooded (maintain a high and constant body temperature independent of the
surroundings), give live birth, nurse their young, breathe air, and have hair.
Since they live in the marine environment and they find their food at sea,
pinnipeds are called marine mammals. Other marine mammals include whales and sea
otters.
Although most of their lives are spent in the water, pinnipeds, unlike whales
and dolphins, are also dependent on land. Pinnipeds may come ashore periodically
to rest and bask in the sun, and at least once each year, during their breeding
season, most species congregate on beaches or sea ice to give birth and breed.
A pinniped's body is insulated with a thick layer of fat called blubber.
Blubber lies just under the skin. Besides reducing the amount of body heat lost
to cooler surrounding waters, blubber contributes to a pinniped's streamlined
shape and stores energy.
A streamlined shape produces less resistance and helps a pinniped conserve
energy as it swims. |
