The Heartbeat of a Blue Whale

The blue whale, the largest animal known to have ever existed, has a heart that weighs approximately 1,300 pounds—almost as much as a small car.

But what's truly remarkable is the creature's heartbeat.

According to a study published in the journal Proceedings of the National Academy of Sciences, a blue whale's heart beats only two times per minute on average when the creature dives into the water.

The study observed the lowest heart rate ever noted for a blue whale, just two beats per minute—far slower than the beat of your own heart at rest.

Additionally, between beats, the whale's heart rate can accelerate to 37 beats per minute after resurfacing from a dive.

The extreme swing in the heartbeat is due in part to the physical demands of diving deep underwater and then reoxygenating at the surface..