Maureen Hegarty, age 8, of Whitehall, Pa., for her question:
HOW MANY TYPES OF WHALES ARE THERE?
Largest animal that has ever lived is a whale. Whales are much larger than elephants and even out measure prehistoric dinosaurs. The blue whale may grow to be 95 feet long and weigh up to 150 tons. When a baby is born to the blue whale he may measure 23 feet in length and weigh up to three tons.
Whales are mammals, not fish. They will drown if trapped underwater.
There are two main types of whales: whales that do not have teeth and those that do have teeth.
Whales without teeth are called baleen whales. They have horny plates in their mouths that strain out their food from the water. The plates are called baleen, and they hang in two rows, like curtains, one on each side of the whale's upper jaw. The inner edges of the plates have a fringe of bristles that strain out food.
Female baleen whales are larger than males. They belong to a suborder of whales called Mysticeti.
Toothed whales have peglike teeth that vary in number. A sperm whale will have from 36 to 56 teeth, all in his lower jaw. Other kinds of toothed whales may have only two or four teeth, also located in the lower jaw only.
Male toothed whales are larger than the females. Dolphins and porpoises also have peglike teeth, and scientists classify them along with toothed whales in a suborder of whales called Odontoceti.
Included among the baleen whales is the giant blue whale. Also included in the same family is the pygmy Right whale, that is only 20 feet long and weighs between three and four tons. He has 17 pairs of ribs compared with the 13 to 15 pairs in most other whales.
The bottle nosed whale comes from the popular toothed family. He measures about 30 feet in length and weighs about 10 tons. He's found in the North Atlantic.and also the Antarctic regions. In his mouth are four teeth. Found in all oceans is the Killer whale, who is actually a large porpoise. He's usually about 30 feet long and weighs 10 tons. Between 40 and 48 teeth can be found in his mouth. Also found in all oceans is the 60 foot long Sperm whale, the largest creature in the toothed whale family.
The skeleton 'of a giant blue whale makes up only about 17 percent of the animal's body weight. This is much less a percentage than the skeleton of a land animal. Reason for this difference is that water helps support the whale's body, but the bones of a land mammal must carry its entire weight.
All mother whales nurse their babies underwater. The baby, called a calf, drinks his mother's milk for about six months.