Nepedia
Back to Discover
Advanced Reader
🧬

Vaquita

life science Maturity 5-7 climate Next article →

This article covers sensitive topics: climate. Parents can manage visibility in Parental Controls.

The vaquita (Phocoena sinus) is a rare species of porpoise. It is endemic to the northern end of the Gulf of California in Mexico. This means it lives in no other place on Earth. The vaquita is the smallest of all living cetaceans, which is the group including whales and dolphins.

Vaquita2 Olson NOAA
Vaquita2 Olson NOAA

Because its habitat is so small, it has the smallest range of any cetacean. Today, the species is on the brink of extinction. The IUCN Red List classifies the vaquita as Critically Endangered. This is the highest level of risk before a species is gone forever.

Physically, the vaquita is easy to recognize. It has a small body and a rounded head without a distinct beak. Its coloration is mostly grey, with a darker back and a white ventral field, which is its underside.

Vaquita2 Olson NOAA
Vaquita2 Olson NOAA

It features prominent black patches around its eyes and lips. The species also has an unusually tall, triangular dorsal fin. There is noticeable sexual dimorphism, meaning males and females look different. Mature females are longer, with larger heads and wider flippers. Females reach a maximum length of about 1.5 meters. Males reach about 1.4 meters. They weigh between 45 and 55 kilograms.

Understanding the vaquita requires looking at its history and biology. In 1958, zoologists Kenneth S. Norris and William N. McFarland defined the species. They did this by studying the morphology, or physical structure, of skull specimens found on a beach. It took nearly thirty years to fully describe their external appearance. This happened in 1985 when scientists studied fresh specimens. Their ancestors likely moved north across the equator more than 2.5 million years ago. This movement occurred during the Pleistocene, a period of cooling on Earth. Genetic sequencing from a 2017 specimen shows the species survived a major population bottleneck in the past. This history may help the remaining individuals stay healthy despite low numbers.

As a generalist, the vaquita eats many different things. Its diet includes various demersal fish, which live near the bottom of the sea. It also eats crustaceans and squids. Most of its food comes from benthic fish, such as grunts and croakers. Vaquitas usually live alone or in pairs. They are often seen with a calf. However, they have been observed in small groups of up to 10 individuals. They live in shallow, turbid waters that are less than 50 meters deep. Their estimated life expectancy is 20 years. They reach sexual maturity between 3 and 6 years of age.

Reproduction in vaquitas is a slow process. They have a polygynous mating system, where males compete for females. This competition is suggested by their large testes, which make up nearly 3% of their body mass. The females have long gestation periods, which is the time a pregnancy lasts. This period is between 10 and 11 months. They usually give birth to a single calf between February and April. Because they often give birth only every other year, they are considered a K-selected species. K-selected species are more vulnerable to extinction. They cannot repopulate as quickly as other types of animals.

The primary threat to the vaquita is bycatch.

Vaquita3 Olson NOAA
Vaquita3 Olson NOAA

Bycatch is the incidental catch of animals that fishermen do not intend to catch. Vaquitas get tangled in gillnets used by the illegal totoaba fishery. The totoaba is a fish whose swim bladders are sold on the black market. Even though Mexico implemented a gillnet ban in 2015, illegal fishing continues. This has caused a massive decline in their numbers. In 1997, there were about 567 vaquitas. By 2007, only 150 remained. By 2018, fewer than 19 were left. As of 2023, scientists estimate as few as 10 remain in the wild.

Conservation efforts are active but difficult. The Mexican navy has placed concrete blocks with rebar hooks in the water. These blocks are designed to destroy illegal gillnets in the zero tolerance area.

Statue of "Vaquita Marina" in San Juan de Aragón
Statue of "Vaquita Marina" in San Juan de Aragón

This has helped reduce the number of fishing boats in certain areas. Scientists are also studying the "anthropogenic Allee effect." This occurs when a tiny population size leads to low fitness due to a lack of genetic diversity. However, some studies suggest the vaquita's history of small populations might protect them from inbreeding depression. Efforts to keep them in captivity have failed and caused stress to the animals. The goal remains to stop bycatch so the species can recover in its natural home.

733 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (3)
File:Vaquita2 Olson NOAA.jpg
Vaquita2 Olson NOAA.jpg
File:Vaquita3 Olson NOAA.jpg
Vaquita3 Olson NOAA.jpg
File:Statue of "Vaquita Marina" in San Juan de Aragón.jpg
Statue of "Vaquita Marina" in San Juan de...
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.