International Seal Day丨How did the spotted seal, a shore “larvae”, become a diving champion?

March 1st of every year is "International Seal Day". The establishment of this international theme day aims to arouse human attention to the living environment of seals and marine ecological issues.

There lives a group of cute and adorable marine mammals in the Yellow Sea and Bohai Sea of ​​my country. It is a national first-class protected animal, the Western Pacific spotted seal, which is known as the "Pearl of the Bohai Sea"!

The spotted seal is a fat and sturdy creature with a rounded front body and a spindle shape. It is called the "giant panda of the sea" for its cute appearance. It is a pinniped marine mammal that lives in the coastal areas of temperate and cold temperate zones. It is mainly distributed in the Bohai Sea and the northern Yellow Sea in my country. It is the "flagship" species of the marine ecology of the Yellow Sea and Bohai Sea in China.

In the process of evolution, the limbs of the harbor seal gradually formed a structure shaped like a fish fin, which can help it move better on land and in water. Although it moves clumsily on land and can only rely on the peristalsis of its forelimbs and upper body, once it dives into the water, the muscle valves in its nostrils and ear holes will immediately close to prevent seawater from pouring into its ears and nose.

They are veritable "swimmers and divers". They can stay underwater for about 70 minutes and often dive to 400-500 meters or even deeper. All of this depends mainly on sufficient oxygen, and harbor seals have three main ways to store oxygen:

1. Store oxygen in the blood.

2. Using its obese body to store oxygen, the respiratory pigments contained in the muscles of spotted seals are many times higher than those of terrestrial animals, and the oxygen storage capacity can account for about 50% of the total body oxygen storage capacity.

3. Save oxygen by holding your breath and slowing down your heartbeat.

Due to illegal hunting, marine development and overfishing, the living environment of spotted seals is threatened. Spotted seals are the only pinnipeds that breed in my country. Once they leave the Yellow Sea and Bohai Sea, China will no longer have resident pinnipeds. Therefore, the task of protecting spotted seals is imminent!

March 1st of every year is International Seal Day. We hereby call on everyone to protect the marine environment and resources, cherish and protect marine life, and retain the precious "giant panda of the sea" - the Western Pacific spotted seal.