Whales are marine mammals that inhabit all the world's oceans and, unlike any fish, move their flukes in an up-and-down motion.
Toothed whales have a single blowhole and actively prey upon fish, seals and even other whales. Toothed whales have lost their sense of smell yet have developed echolocation. The other major group of whale, the bristle toothed (or baleen) whales, strain their food from water using bristle-like structures in their mouths. Baleen whales have two blowholes and females are usually larger than males. The Blue Whale, the largest living animal of all time, feeds almost exclusively on krill. Jul 5