Short answer: Sperm whale
Humans can hold their breath for, at most, a few minutes. But, imagine if you could hold it for an hour and a half! A sperm whale can do just that, and scientists have officially discovered how.
Researchers at the University of Liverpool studied a molecular protein called myoglobin in 100 mammals ranging from cows, otters, and whales. The protein stores oxygen in muscles. They found in deep-diving mammals, like sperm whales, the proteins became more electrically charged.
The charge prevents myoglobin from clumping, which means the animal can have more of it — and more oxygen — in its muscles. The amount of myoglobin a mammal can store makes a big difference.
Science World Report says the longest a human has ever held his breath for is 22 minutes. And that was after breathing pure oxygen first and not moving underwater. Compare that to the 45 minutes to 2-hour dives sperm whales take.
The researchers also traced the changes in myoglobin in deep-diving mammals through 200 million years of evolution and discovered those that could hold their breath longest evolved a nonstick variety of myoglobin.
The findings could aid medical research and will lead to a better understanding of the evolution of marine mammals. One researcher said, “The idea that we can estimate maximal dive times for early-diverging relatives of today’s marine mammals will have a profound impact on how we think about their ancient ecology and biology.”