E X T E N S I O N WHALES Classi cation There are two major groups of whales: the baleen whale (Mysticeti), which does not possess teeth, but has hundreds of thin, vertical membranes hanging from the upper jaw, called baleens, used as a lterfeeding system; and the toothed whale (Odontoceti), which possesses teeth, as the name says. The former includes 14 species, among which: right, gray, blue, humpback, and nback whales; the latter comprises 77 species, among which: sperm, beluga, beaked whales, and narwhals. Baleen whales may live 40 years, toothed whales up to 90. Characteristics Whales are the heaviest animals, reaching a maximum size in the blue whale of more than 30 m. and 200 metric tons. Whales are distributed throughout the world s oceans and seas, from the Equator to the polar ice. They are mammals and share the common characteristics of that group: they breathe air, are warm-blooded, give live birth, feed their young (called calves) on milk and have hair. All are entirely aquatic, with specialized adaptations such as ippers and tail ukes (see p. 7). 3 meters 9 feed CETACEANS blue whale humpback whale gray whale narwhal n whale beluga sperm whale sei whale bowhead, or Greenland right whale minke whale dolphins northern right whale Baird s beaked, or giant bottlenose whale 58 killer whale, or orca porpoise