Vaquita Basics

1 The vaquita, Phocoena sinus, is the world’s smallest cetacean, weighing around 55 kilos.

2 Females grow to be around 1.5 metres long. They are longer than the males, whose length tops out at about 1.4 metres.

3 They eat small fish and squid.

4 They have unique facial markings with a black ring around each eye and curved, black lips that make them look as if they are smiling.

5 Their dorsal surface is dark grey, their sides pale grey, and their underside is white with light grey markings. Newborn calves are darker.

6 Vaquita have proportionally large dorsal fins, possibly as an adaptation to warmer water to allow heat to dissipate.

7 Like other porpoises, vaquitas use sonar to communicate and navigate.

8 Vaquitas are very rarely seen. When they are spotted, they are either alone or in small groups of two or three. They are thus thought to be quite solitary animals.

9 Researchers estimate that vaquita live for around 20 years.

Threats

Vaquita are disappearing as a result of their being caught and drowned by gillnets, as bycatch.

Many of their numbers have been killed by gillnets as part of the illegal fishery for a fish called “totoaba”. 

The totoaba is also a critically endangered fish species, targeted for its swim bladder, which is mistakenly believed to have applications in Chinese medicine; tortoaba swim bladders will sell for as much as USD 8,000 per kilo on the black market.

Breeding

• Females reach sexual maturity between 3 and 6 years old, and will give birth roughly every 2 years.

• Vaquita will mate during April and May.

• They will have one calf which gestates for 10–11 months.

Most vaquita calves are born in March and April.

• Vaquita calves are around 70 centrimetres long at birth, and weigh about 8 kilos.

Population

CRITICALLY ENDANGERED

In 2017, it was estimated that the vaquita population had dropped to fewer than 30.

Their population was thought to be around 600 in 1997.

Distribution

The geographic range of the vaquita is the smallest of any marine mammal – it is a patch of water of roughly 2,330 square kilometres, in the northern part of Mexico’s Gulf of California. The vaquita is also the only porpoise species found in such warm waters.

Their habitat is specialised; they live within 25 kilometres from shore in shallow lagoons, in water between 10 to 28 metres deep.

Read the rest of this article in No. 109 Issue 3/2017 of Scuba Diver magazine by subscribing here or check out all of our publications here.

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