General science of WHALES

Whales are a diversified group of totally aquatic placental marine animals with a vast distribution. They are a loose classification within the Cetacea infraorder, which normally excludes dolphins and porpoises. The order Cetartiodactyla, which includes whales, dolphins, and porpoises, is made up of even-toed ungulates. Whales range in size from the dwarf sperm whale, which is 2.6 meters (8.5 feet) long and weighs 135 kilogrammes (298 pounds), to the blue whale, which is 29.9 meters (98 feet) long and weighs 190 metric tonnes (210 short tonnes).