A Blue Whale's Heart Is the Size of a Car

To power the largest animal ever to have lived requires an engine of epic proportions. The blue whale’s heart, weighing around 400 pounds and comparable in size to a small car, is a masterpiece of biological engineering. This colossal pump circulates thousands of gallons of blood through a body that can stretch up to 100 feet long. Its main artery, the aorta, is so wide that a small adult could comfortably swim through it. This incredible scale is a direct adaptation to the whale's immense size and aquatic lifestyle, a challenge no other animal has ever faced.

The heart's rhythm is just as remarkable as its size. To conserve oxygen during deep dives, it beats at an incredibly slow rate of 8 to 10 times per minute, and can even drop as low as two beats per minute while submerged. These powerful, low-frequency thumps are so loud they can be detected by sonar equipment from more than two miles away. For many years, the exact anatomy of this organ was a mystery, but in 2014, scientists were able to preserve the heart from a beached whale, allowing for the first-hand study of this magnificent natural wonder.