What do you think of this fact?
Measuring a blue whale’s pulse is harder than it sounds. You can’t exactly ask the largest animal in the world to hold still for a moment. Still, researchers managed it for the first time in 2019.
A sensor with suction cups
According to Live Science, a team in Monterey Bay, California, attached a sensor with suction cups to a blue whale’s body. According to Live Science, it worked on the very first attempt, which is no small feat with such a huge, fast animal. The results were published in the journal PNAS on November 25, 2019.
According to ScienceAlert, the device collected about nine hours of data. The whale was about 22 meters long.
Almost a standstill, then full throttle
The result surprised the researchers. While the whale was diving, its heart rate dropped to just 2 beats a minute, according to Live Science. According to ScienceAlert, four to eight beats a minute were typical during dives.
When it came back up to breathe, its heart raced at up to 37 beats a minute. According to Live Science, the simple act of catching a bite may push a blue whale’s heart to its physical limits.
A dive lasted up to 16.5 minutes and went as deep as 184 meters. During that time, the whale was hunting for food underwater.
Bonus fact: According to Live Science, a blue whale’s heart weighs about 180 kilograms (400 pounds). That’s roughly as much as two or three adults combined, and it’s about the size of a golf cart.
Why does the heart beat so slowly during a dive? It saves oxygen. The blood then mainly supplies the most important organs, and the whale can stay underwater longer.
For comparison: a human heart beats about 60 to 80 times a minute at rest. In the deep, the blue whale gets by with a fraction of that and is still the largest animal that has ever lived.