cetacean

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Related to cetaceous: Sirenians

cetacean

or

whale

any aquatic EUTHERIAN mammal of the order Cetacea, comprising the porpoises, dolphins and whales.

Cetaceans are completely aquatic, have lost their hind limbs during evolution and have fin-like forelimbs, often a dorsal fin and, in marked comparison with fishes, a blowhole and transverse tail fin. The young are large at birth and suckled like other mammals. Cetaceans possess an extensive outer layer of fat associated with their marine habit, have a large brain and are capable of complex communication.

cetacean

includes the marine mammals of the order Odontoceti, the whales and their congeners, the dolphins, grampuses and porpoises.