A young Cuvier's beaked whale calf surfaces to breath alongside its mother. Credit: Brenda Rone, under NMFS permit #15330.

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.

Go deeper

Trump tightens screws on ByteDance to sell Tiktok

Illustration: Aïda Amer/Axios

President Trump added more pressure Friday night on China-based TikTok parent ByteDance to exit the U.S., ordering it to divest all assets related to the U.S. operation of TikTok within 90 days.

Between the lines: The order means ByteDance must be wholly disentangled from TikTok in the U.S. by November. Trump had previously ordered TikTok banned if ByteDance hadn't struck a deal within 45 days. The new order likely means ByteDance has just another 45 days after that to fully close the deal, one White House source told Axios.

Updated 10 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Aïda Amer/Axios

  1. Global: Total confirmed cases as of 9:30 p.m. ET: 21,056,850 — Total deaths: 762,293— Total recoveries: 13,100,902Map.
  2. U.S.: Total confirmed cases as of 9:30 p.m ET: 5,306,215 — Total deaths: 168,334 — Total recoveries: 1,796,309 — Total tests: 65,676,624Map.
  3. Health: CDC: Survivors of COVID-19 have up to three months of immunity Fauci believes normalcy will return by "the end of 2021" with vaccine — The pandemic's toll on mental health — FDA releases first-ever list of medical supplies in shortage.
  4. States: California passes 600,000 confirmed coronavirus cases.
  5. Cities: Coronavirus pandemic dims NYC's annual 9/11 Tribute in Light.
  6. Business: How small businesses got stiffed — Unemployment starts moving in the right direction.
  7. Politics: Biden signals fall strategy with new ads.

Harris: "Women are going to be a priority" in Biden administration

Sen. Kamala Harris at an event in Wilmington, Del. Photo: Drew Angerer/Getty Images

In her first sit-down interview since being named Joe Biden's running mate, Sen. Kamala Harris talked about what she'll do to fight for women if elected VP, and how the Democrats are thinking about voter turnout strategies ahead of November.

What they're saying: "In a Biden-Harris administration women are going to be a priority, understanding that women have many priorities and all of them must be acknowledged," Harris told The 19th*'s Errin Haines-Whack.