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Whales

A grey whale and her calfA grey whale and her calf Whales are ocean-living mammals that live permanently in the water. Together with dolphins and porpoises, they make up the group of mammals called cetaceans. Whales have a long, streamlined shape with no hair or fur on their bodies, so that they can swim quickly and easily. Instead of four legs, they have a tail, called a fluke, and flippers. Whales have a thick layer of fat under their skins, called blubber, to keep them warm in cold waters. As air-breathing mammals, whales have to come to the surface of the water to breathe air. They have excellent hearing, but a poor sense of smell. There are two types of whale: toothed whales and baleen whales.

Size

Blue whaleBlue whaleWhales are the largest animals in the world. In fact, the enormous blue whale, which can measure over 30 metres (100 feet) long, is probably the biggest animal that has ever lived. Whales are able to grow so large because their huge weight is supported by the water. If a land animal grew to this size, its legs would collapse under the weight of its own body.
 

A whale spoutingA whale spouting

Breathing

All whales must come to the water's surface from time to time to breathe. While a whale is submerged, its nostrils, or blowholes, remain shut. When it comes to the surface, it breathes out in an explosion of waste air and water droplets known as a "blow" or a "spout". Different whale species can be distinguished by the form of their spout. Baleen whales have two blowholes side by side on top of their heads; toothed whales have just one.

Despite their names, the killer whale and pilot whale are considered to be dolphins rather than whales.

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