The longest breath ever recorded, in whales

The Cuvier's beaked whale is the undisputed champion of the long, deep dive. In a study released this week, Erin Falcone and her team recorded a record-shattering dive: one whale held its breath for an astounding two hours and 43 minutes.

"When I first saw the data, I thought 'is there any limit to what this animal can do'?" Falcone tells Axios. (When she recorded a two hours and 17 minute dive in 2014, she said, "it blew us out of the water.")

How they do it: The whales have a number of adaptations to help them hunt beneath the waves. They can almost empty and refill their entire lungs in a single breath. When humans breathe, oxygen is taken from our lungs via a protein called hemoglobin in our blood. Whales have hemoglobin, too — but they have a lot more of it. Both also have myoglobin, another oxygen-storing protein, in their muscles. Cuvier's beaked whales have more myoglobin than most diving mammals and far more than humans. "Their muscles are almost black with myoglobin," says Falcone.

The whales have other ways to conserve oxygen: on deep dives, they temporarily shut down their liver and kidneys and pull blood from their extremities. Their ribs collapse and fold, which helps remove air pockets and makes it easier for them to dive. The whales don't need to swim to reach those depths: they just hold their breath and sink into the black.