Vaquitas live in the upper area of the Gulf of California, near the mouth of the Colorado River. No other marine mammal has such a small range, and consequently vaquitas are extremely rare and may become extinct.

Vaquitas used to be able to swim up into the mouth of the Colorado. However, in recent years so much water has been removed from the river for irrigation and for supplying cities that the Colorado is little more than a trickle where it reaches the ocean. This has probably changed the composition of the Gulf waters, too. The vaquita population was also affected by the fishing industry in the Gulf. Fishermen drowned many vaquitas in their nets by accident, and their activities have also reduced the amount of fish available for the porpoises to eat.

Most vaquitas have dark grey or black upper bodies, with paler undersides. Like other porpoises, the vaquita has a blunt face. Its triangular dorsal fin is reminiscent of a shark's. Vaquitas live in pods of up to five animals.

Biologists know little about the lives of these porpoises. Vaquitas probably spend most of their time alone, locating their prey close to the sea floor using echolocation.

Births probably take place all year round.

Distribution: Gulf of California in the eastern Pacific.

Habitat: Coastal waters and mouth of the Colorado River.

Food: Fish and squid.

Size: 1.2 - 2 m (4 - 6.5 ft); 45 - 60 kg (99 - 132 lb).

Maturity: Unknown.

Breeding: Probably 1 calf.

Life span: Unknown.

Status: Critically endangered.