Phocoenidae

Phocoenidae, commonly known as porpoises, are a family of small to medium-sized toothed whales within the suborder Odontoceti. They are distinguished from delphinids by a stout body, a short, blunt snout, and spade-shaped teeth, and by a dorsal fin that is typically triangular and small. Porpoises inhabit temperate and some subarctic seas, mostly in coastal or shallow offshore waters, though some species venture into deeper waters.

The family comprises several species in the genera Phocoena, Phocoenoides, and Cephalorhynchus. Representative species include the harbor porpoise (Phocoena phocoena), the vaquita (Phocoena sinus), and the Dall's porpoise (Phocoenoides dalli). The Cephalorhynchus genus includes species such as Hector's dolphin (Cephalorhynchus hectori), Commerson's dolphin (Cephalorhynchus commersonii), and the Chilean dolphin (Cephalorhynchus eutropia).

Porpoises feed mainly on fish and squid, employing echolocation to locate prey in murky coastal waters. They are generally shy and live in small to moderate groups, though some species may form larger aggregations. Reproduction typically involves a single calf born after a gestation of about 10-12 months; calves nurse for several months to a year.

Conservation: The main threats are bycatch in gillnet and seine fisheries, habitat degradation, pollution, and fishing gear entanglement. The vaquita is critically endangered with a severely reduced population, and other porpoises face localized declines. Protected areas and fishing regulations have helped some populations, but many species remain at risk.