Vaquita

## Description

Vaquitas (Phocoena sinus) are record-holders among all cetaceans. Thus, these animals are the smallest cetaceans, meanwhile being the smallest porpoises; they have the smallest range; and finally, vaquitas are the most critically endangered cetacean species in the world. ‘Vaquita’ is a Spanish word meaning "little cow". The scientific name of this animal means “porpoise of the gulf”, as this cetacean is endemic to Mexico. Vaquitas are a quite recently discovered species: they were first identified in 1958 based on skulls and were first observed in 1985.

## Appearance

The vaquita can be easily distinguished from any other species in its range. It has a small body with an unusually tall, triangular dorsal fin, a rounded head, and no distinguished beak. The coloration is mostly grey with a darker back and a white ventral field. Prominent black patches surround its lips and eyes. Mature females are typically longer than males and have larger heads and wider flippers.

## Distribution

Vaquitas inhabit the upper Gulf of California (also called the Sea of Cortez), making this the smallest range of any marine mammal species. They live in shallow, turbid waters of less than 150 m (490 ft) depth. Vaquitas live in murky warm waters within 16 miles (25.7 km) of the shoreline since there is high food availability and a strong tidal mix.

## Behavior

Vaquitas can be found solitarily, in pairs as well as in groups, consisting of up to 7 individuals. These shy and secretive animals do not tend to perform acrobatic maneuvers. When coming to the surface to breathe, they move slowly and are quite difficult to spot, barely disturbing the surface and diving back into the water. As common in cetaceans, these animals are known to use echolocation when looking for prey. However, some species of fish these cetaceans consume, give out specific sounds, suggesting that Vaquitas are likely to find them due to these sounds instead of using echolocation. They also use echolocation when communicating with conspecifics in areas with murky waters.

## Diet

Vaquitas are carnivores (piscivores). Feeding at the water’s surface, this animal mainly consumes teleost fish, squid, and crustaceans.

## Reproduction

Vaquitas are polygynous, which means that one male gets the exclusive right to mating with multiple females. They mate from mid-April to May and give birth to a single calf, usually in early March, after a gestation period of approximately 10-11 months. The newborn calf is nursed by its mother for 6-8 months, reaching sexual maturity at 3-6 years old.

## Population

### Population threats

Presently, the primary threat to this Critically Endangered species is commercial and artisanal fishing. These animals are known to become entangled in the gill nets and trawl nets, used by fisheries, which endanger the lives of 39-84 Vaquitas every year. In addition, because of the extremely small population, Vaquitas are threatened by interbreeding. Other notable concerns include environmental pollution and the degradation of their natural habitat.

### Population number

According to the IUCN Red List, the total population of Vaquita includes less than 250 mature individuals. Currently, this species is classified as Critically Endangered (CR), and its numbers are decreasing.

## Fun Facts

Vaquita is the only porpoise, living in warm waters such as these of the Gulf of California: porpoises inhabit cooler waters, typically lower than 20 degrees Celsius. Another distinctive feature of Vaquita is its ability to tolerate large annual fluctuations in temperature, which is also uncommon in porpoises. The temperature of water in the Gulf of Mexico, where these animals are found, varies from 14 degrees C in winter to 36 degrees C in summer.

Along with using clicks, this animal emits a very harsh and loud sound, similar to that of a Harbor porpoise.

Living in murky waters, this animal cannot find prey by only using its eyesight. Hence, Vaquita uses echolocation, emitting high-pitched sounds, which pass through the water and bounce, bringing information on the size and type of a given object and helping determine whether it's edible or not.

These shy animals do not tend to jump out of water or even swim at the surface. Moreover, they usually avoid vessels and humans.

Vaquitas have black lips and black rings around their eyes. According to scientists, this is due to catching their food.