Instead of teeth, they have plates made of baleen in their jaws. Baleen is a very hard and strong substance, much like the material that makes animals horns. Baleen is also called whalebone. The baleen plates grow from the whales upper jawbones. They are from two to 12 feet long and they hang down in stringy pieces.
Sea water passes through the baleen and the whales food gets caught.
A kind of plankton called krill is what the baleen whale eats. There are many kinds of baleen whales, including blue, bowhead, Bryde s, fin, gray, humpback, minke, right and sei. The blue whale is the largest, often reaching 100 feet in length. They are the largest animals that have ever lived upon the earth. Humpback whales are also big, weighing up to 45 tons.