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.
Baleen whales have two nostrils, or blowholes.
They include the beluga or white, bottlenose, narwhal, pilot and sperm whales. Dolphins are toothed whales. The famous killer whale, is really a large dolphin, and they can grow up to 30 feet in length. Toothed whales eat fish and plants. They have one nostril, or blowhole.