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Baleen whales have no teeth. Instead, they have hundreds of thin plates in the mouth. A whale uses these plates to strain out food from the water. The plates, which consist of the same material as human fingernails, hang from the whale's upper jaw. The inside edges of the plates have brushlike fibers that filter out the food. Baleen whatles feed mainly on plankton --drifting masses of tiny plants and animals.
Scientists divide baleen whales into three groups: right whales, gray whales, and rorquals.
Right Whales have a thick, solid body and an unusually large head. The head of most right whales makes up about a third of the total body length. Right whales swim slowly, averaging about 3 miles per hour. They feed by swimming into a mass of plankton with their mouths open. Water flows through the baleen, and the plankton becomes entangled in the baleen fibers. There are three main kinds of right whales: bowhead whales, black right whales, and pygmy right whales.
Gray Whales live in the North Pacific Ocean. In spite of their name, they may be black or dark gray. They may measure up to 50 feet long. Gray whales eat small animals that live on the sandy ocean bottom. The whales scoop up the sand and use their baleen to strain out the animals. They also feed on plankton and small fish.
Rorquals are baleen whales that have long grooves on the throat and chest. These grooves may number from 10 to 100 and are 1 to 2 inches deep. They enable a rorqual to open its mouth extremely wide and gulp enormous quantities of food and water. As the whale closes its mouth, its tongue forces the water out of the mouth through the baleen. The food becomes trapped inside the baleen and is swallowed by the whale. All rorquals have a dorsal fin, and so they are sometimes called finback whales. Most of them have a long, streamlined shape and can swim faster than other whales. There are six kinds of rorquals: blue whales, Bryde's whales, fin whales, humpback whales, Minke whales, and sei whales.
Library >> Science >> Zoology >> Mammals >> Order Cetacea
This page was last updated on October 30, 2017.