Whales are huge gentle beasts that live in the sea in the calmness of the deep. They look very much like fish, but they are quite the opposite. They belong instead to the certain group of animals known as mammals. Other mammals are creatures you are familiar with, such as chimpanzees, dogs, cats, apes, monkeys, and  human beings. Like these whales have a highly developed brain and so they are the most intelligent of all animals. Whales are enormous creatures, with their powerful massive bodies. One kind, the blue whale, is the largest animal that has ever lived. Blue whales will grow up to 100 feet long and weigh up to 220 short tons. Although there are large whales, there are whales that are much smaller. The Beluga's and the Narkample grow only 10 to 15 feet long.

    They have the same basic shape as fish, but they have several differences from fish. The most visible difference between the whale and the fish is their tails. Fish have vertical (up and down) tail fins, while whales have sideways tail fins. Fish breathe by using their gills, which absorb dissolved oxygen from their surrounding water. Whales, however, have lungs and must surface for air periodically. They can hold their breath for long periods of time. One type of whale, the Sperm whale, can hold its breath up to 2 hours. Like other mammals, whales give birth to live young and feed them with the milk that is produced by the mother's body. Most fish, however, lay eggs and do not feed their offspring. Whales are also warm-blooded- which means their body temperature remains about the same whether their surroundings are warm or not. Almost all fish are cold-blooded. Their body temperature will change by the temperature of their surroundings. Through the ages, whales have gradually lost some of their characteristics of mammals. For example, most mammals have hair all over their bodies, while a whale only has a few stiff hairs on its head. Most mammals also own four legs, and a whale has no hind legs. The only traces of their existence that remains are two tiny hip bones. In addition, their front legs have developed into flippers, which helps the whale steer and keep its balance.

    People have hunted whales since the Prehistoric times. In the early days, people would kill whales for their meat, and for their whale oil, which they used for fuel for oil lamps. They also used the fuel for cooking. Until the 1970's, whale oil and other parts of the whale's body were used for many products, like Cosmetics, fertilizer, glue, medicines, and soap.Today, the people of Japan, as well as native people in Arctic regions, still eat whale meat.

    During the 1900's, whaling fleets have killed huge amounts of whales and doing so has endangered the survival of some kinds of whales. For this reason, the International Whaling Commission also completely prohibits the killing of of those certain kinds of whales. The United States government forbids whale products to be imported.

    Whales belong to a group of mammals called cetaceans. This name comes from the Latin word meaning large sea animal. Scientists have identified at least 75 of these cetaceans. They divide the various kinds of cetaceans into two major groups- the baleen whales, which have no teeth, and the toothed whales, which have their teeth. It discusses the chief kinds of whales in each group. It also discovers the bodies of whales and the life of whales. Lastly, it traces the history of whaling and looks at the future of whales.

Baleen whales don't have any teeth. Instead, the have hundreds of thin plates inside their mouth. A whale uses these plates to strain their food out of the water. The plates are called baleen, or whalebone and consist of the exact same material as human fingernails. The baleen hangs from the whale's upper jaw. The inside edges of a plate has brushlike fibers that filter out their food. Baleen whales mainly eat plankton, which are drifting matter of aquatic organisms.

    There are 10 different kinds of baleen whales. Scientists divide them into groups of three, the right whales, the gray whales, and the rorquals.

       Right whales have a dense, solid body and an unusually large head.