The Vaquita is a marine mammal

There are approximately 100 species of mammals that depend on the sea for the majority of their life needs. They are known as marine mammals and can be divided into three large groups: Pinnipeds (seals, sea lions and walruses), Sirenians (manatee) and Cetaceans (whales, dolphins and porpoises). The Vaquita is a marine mammal in this last category.

All mammals share certain characteristics, such as warm bloodedness (distinct from reptiles, for example), a hairy covering over their bodies, their young develop inside the mother and are nursed with milk, and they breath air with their lungs.

Mammals that live in the water have developed a series of characteristics or adaptations to aquatic conditions, including changes to the skin. A thick layer of blubber or a dense coat of hair and adjustments to the circulatory system help aquatic mammals minimize the loss of body heat to cold waters. The eyes, nose, ears and extremities are also adapted to the aquatic environment. One especially notable adaptation is the ability of some cetaceans to produce high frequency sounds that travel through water help in navigating, hunting food and communicating.

Aquatic mammals are able to dive deep, possessing flexible ribs wish prevents the lungs to collapse, and they also have bones in the middle ear that can support the tremendous pressures of great depths. Their circulatory system is also adapted to deep diving with the ability to slow the heart rate, minimize consumption of oxygen and concentrate blood in vital organs such as the heart, lungs and brain.

Most marine mammals can live in salt water because their specialized kidneys conserve water by being very efficient in concentrating body wastes.