Whales

Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and porpoises. Dolphins and porpoises may be considered whales from a formal, cladistic perspective. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates. Their closest non-cetacean living relatives are the hippopotamuses, from which they and other cetaceans diverged about 54 million years ago. The two parvorders

phenomenon in which a whale becomes stuck on a beach, often causing the whale's death

phenomenon of a beached whale exploding due to explosives or decomposition

temporary ecosystem resulting from the fall of a whale carcass to the ocean floor

species of Secernentea, a parasite of the placenta of sperm whales

behaviour of whales and dolphins when they come to the surface to breathe

feeding method used by humpback whales

excrement of whales and its role in the ecology of the oceans