The secret to dive deep dolphins without fainting

Some species of seals and dolphins can hold their breath in the water for hours without fainting from lack of oxygen. Absolutely you don't try it at home, because people can hardly bear it for more than a minute without breathing.

Scientists have recently found the secret of these marine mammals: the presence of a large density of oxygen-containing special proteins in their brains .

Scientists have long wondered why marine mammals, such as dolphins, whales, seals, sea otters, can be accommodated in such a severe shortage of oxygen. The simplest explanation is that they have evolved to enhance the supply of oxygen to the brain.

But studies have shown that the oxygen content of their blood vessels falls sharply within minutes of diving into the water. " With such oxygen content in arteries, we can faint in the water, " said Terrie Williams research leader, professor of ecological and evolutionary biology at the University of Santa Cruz, California, USA. .

Some marine mammals such as dolphins can tolerate oxygen deprivation due to the increased number of oxygen-containing proteins in the brain.(Photo: Telegraph.co.uk)

Williams and colleagues focused on two newly discovered proteins called neuroglobin and cytoglobin. They are similar to hemoglobin - a molecule that carries oxygen in the blood and operates throughout the body. There are things that neuroglobin and cytoglobin only reside in brain tissue.

Scientists compared the levels of hemoglobin and two types of brain globin in 16 mammals, including terrestrial animals such as mountain lions, American bobbins, bouncing animals that swim in shallow water like dolphin dolphins and California sea lions, and deep diving creatures like pepper whale and Risso's dolphin.

On average, the brains of marine mammals are more hemoglobin and globin than land animals. This proves that these proteins have helped them survive and be alert when diving deep.

However, the research results are not really clear. For example, species that live in shallow and dynamic waters like dolphins, sea lions have higher levels of globin brain than deep-diving whales. Or primates also have high brain globin.

T. An