Norris & McFarland, 1958 - Vaquita
Distinctive Characteristics
The vaquita, or Gulf of California harbour porpoise, is among the smallest of all marine cetaceans. Compared to other phocoenids, it has a taller, more falcate dorsal fin and larger flippers. Like all porpoises, it is stocky, with a blunt beakless head.
Vaquitas have black to dark grey lip patches and eye rings; otherwise the body is light brownish grey fading to white on the belly. Calves tend to be somewhat darker than adults.
In the small number of specimens examined to date, there have been 16 to 22 pairs of teeth in the upper jaw and 17 to 20 pairs in the lower jaw.
Can be confused with
When seen at a distance, the tall dorsal fin of the vaquita must be distinguished from those of bottlenose and common dolphins, both of which are common in the vaquita's range. However, the small group size and unique body shape, as well as differences in behaviour, will generally allow the vaquita to be distinguished.
Size
Known maximum length is 1.5 m (females) and 1.45 m (males), but very few specimens have been examined.
Geographical Distribution
The habitat of the vaquita appears to be defined by relatively murky coastal waters in the northern quarter of the Gulf of California (although there are some suggestions that the range may extend further south in the Gulf as well). This is the most restricted range of any marine cetacean.
Biology and Behaviour
Almost nothing is known of the biology of the Vaquita. As is generally true for porpoises, they occur in small groups and are relatively inconspicuous in their behaviour.
Most calving apparently occurs in the spring.
Exploitation
The vaquita is in imminent danger of extinction, and is listed as an endangered species. The population may number only a few hundred individuals, and at least 30 to 40 are killed each year, mainly in large mesh gillnets set in the northern Gulf for totoaba, sea bass, rays, and sharks. Some are also taken in shrimp trawls. Recently, Mexico has taken some encouraging steps to try to save the vaquita.
IUCN Status
Endangered.