How can marine mammals survive underwater for so long?

Special properties of an oxygen-binding protein in the muscles of marine mammals, such as seals, whales and dolphins, are the reason these animals can hold their breath underwater for long periods of time, according to a new study. ... In fact, the amount was so high in the muscle that it almost looked black in color.

Explanation:

Special properties of an oxygen-binding protein in the muscles of marine mammals, such as seals, whales and dolphins, are the reason these animals can hold their breath underwater for long periods of time, according to a new study. ... In fact, the amount was so high in the muscle that it almost looked black in color.

Explanation:

This is the site that I got the info from, just so you know.  I hope this helps!

Scientists Discover How Marine Mammals Hold Their Breath ...https://blogs.voanews.com › science-world › 2013/06/14

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