Blue whales, gray whales, killer whales and sperm whales are some of the many species of whales. Whales are large marine mammals that are part of the cetacean order, along with dolphins and porpoises.
Whales can be categorized as either baleen whales or toothed whales. Baleen whales feed by filtering plankton and small marine animals like fish and crustaceans out of the water using a comb-like fringe on their upper jaws. Blue whales and gray whales are just two of the 14 species of baleen whales. Blue whales are known for being the largest animal species on earth. They can grow to be 100 feet long and weigh up to 200 tons. Sperm whales and killer whales are two examples of toothed whales that hunt for their food.