The finned porpoises, species of the genus Phocoena, have a dorsal fin. They are distributed throughout the world and include the harbour, or common, porpoise, P. phocoena, found throughout the Northern Hemisphere. The vaquita, P. sinus, found only in the N Gulf of California, Mexico, is the smallest and most endangered species. The finless porpoises, genus Neophocaena, are found in the Indian and W Pacific oceans and in the Chang (Yangtze) River.
The fat of the porpoise yields a lubricating oil, and the flesh is sometimes eaten. In North America the dolphins (family Delphinidae) are sometimes called porpoises and the bottle-nosed dolphin is sometimes called the common porpoise. True porpoises are classified in the phylum Chordata , subphylum Vertebrata, class Mammalia, order Cetacea, family Phocoenidae.
See W. N. Kellogg, Porpoises and Sonar (1961); K. S. Norris, ed., Whales, Dolphins and Porpoises (1966) and, as author, The Porpoise Watcher (1974); R. Ellis, Dolphins and Porpoises (1989).
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Vertebrate Zoology