The Baikal seal (Pusa sibirica) is remarkable for being the only pinniped that is restricted solely to a freshwater habitat. Like other pinniped species, it may look rather ungainly on land, but in water it transforms into a remarkably graceful and agile animal. This is aided by its torpedo-shaped, flexible body, and powerful hindquarters which move side-to-side to propel the seal through the water. Its long, broad, webbed feet act as efficient flippers, while the smaller forelimbs are used to steer. The dense fur of adult Baikal seals is dark silvery-grey on the upperparts, blending into lighter yellowish-grey on the underside, while pups are born with long, white hair. Under the seal’s fur and skin is a thick layer of blubber, which not only provides vital insulation in its icy habitat, but also aids buoyancy, protects the internal organs, and acts as an energy store. Other adaptations for its primarily underwater life include large eyes which enable good vision in deepwater, and ear passages and nostrils that can be closed underwater.