Whale

 Any of the bigger species of aquatic animals that belong to the Cetacea order. The name whale can refer to any cetacean, including porpoises and dolphins, but it is most commonly given to those that are longer than 3 metres (10 feet). The 2.7-metre tiny sperm whale (Kogia simus), which bears a striking likeness to its larger cousin, is an exception. Whales are the heaviest living or fossil creatures, with the blue whale (Balaenoptera musculus) reaching a maximum size of potentially more than 30 metres and 200 metric tonnes (220 short [US] tonnes.Except for the landlocked Caspian and Aral seas, whales can be found in all of the world's oceans and seas, from the Equator to the arctic ice. They are mammals with the following characteristics: they breathe air, are warm-blooded, give live birth, suckle their young with milk, and have hair. All are totally aquatic, with particular adaptations for living in water such as flippers and tail flukes. Whales must surface to breathe on a regular basis, allowing them to eject more air from their lungs than most mammals in an almost explosive breath known as a blow. The water vapor in the whale's hot breath condenses when the blow is released, making the blow visible.