How does a walrus breathe?

Answer 1

Whales are mammals and must breathe air. They breathe not through their huge mouths, but through their blow-hole, which is on the top of their body near the front. They have to come to the surface of the ocean to breathe, so there is a limit to how long they can dive and swim underwater in between breaths.

Answer 2

A narwhal breathes through the combination of a series of inhalations and exhalations. It's able to store the oxygen that it inhales in its blood and lungs. The storage system of blood vessels is particularly complex between the narwhal's lungs and its spine. As in the case of other whales, a narwhal exhales through a blowhole. It is well documented that narwhal dive to the depth of 1500 and even 1800 meters quite often. The length of such dive is often more then 25 minutes. At such depth the water pressure is 150 to 180 atmospheres or bars in scientific terms. There is no rib cage that would be able to withstand such water pressure. Do not forget that narwhal is diving to find and to eat is prey - mostly it is the Greenland halibut, squid and shrimps found near the bottom of the sea. Whale will open its mouth to eat and therefore there is no way the water would be prevented from entering whale's lungs.

Based on the physics I believe that as the whale is diving water is permitted to enter whale's lungs compressing the air to a smaller and smaller bubble which is perhaps is saved somewhere in the scull area closer to the breathing hole. The size of such bubble would be eventually 1/150 to 1/180 of original volume of the lung (depending on the depth of the dive). As the narwhal is surfacing this stored air bubble is expanding eventually completely filling the lung volume at the surface.

I would further speculate that narwhal and other deep diving cetaceans (i.e. whales) are using their lungs not only to obtain oxygen from the air but from the water as well. That is why some whales can dive for 45 min and longer. They are using dual media for oxygen extraction. That is perhaps why whale's exhalations do not smell well - it is due to rotting of some of biological matter that inevitably will be broth in and trapped into the whale lungs with water.

Answer 3

they breathe through an air hole in the back of they head and they must come up from under the water to the waters surface to inhale air through their air hole.

Answer 4

No. They can hold their breath for a long time, but they have to surface to breathe.

Answer 5

With its nostrils and lungs.

Answer 6

with their flippers

Answer 7

By breathing.

Answer 8

air

Answer 9

Nose