The blue whale, the largest animal to ever live on Earth, is a creature of staggering proportions—and its heart is no exception. In fact, the heart of a blue whale is about the size of a small car, weighing up to 400 pounds (180 kilograms). Just imagining a heart that big beating steadily beneath layers of blubber and muscle gives a whole new appreciation for the sheer scale of these marine giants.
But even more mind-blowing is this: you could actually swim through the arteries of a blue whale. Some of its major blood vessels are so wide that a full-grown human could fit through them. These massive arteries are essential for pumping oxygen-rich blood throughout the whale’s enormous body, which can reach over 100 feet in length.
This heart has to work incredibly hard to circulate blood through such a vast body. With each beat, it pushes gallons of blood to support the whale’s muscles, organs, and brain. Despite the intense workload, the whale’s heart rate is surprisingly slow—only about 2 to 10 beats per minute when diving deep. This slower heart rate helps conserve oxygen during long dives and is a key adaptation for surviving in the deep ocean.
Scientists have studied the blue whale’s heart to better understand not just the whale itself, but also how extreme biology works. In 2015, a preserved blue whale heart was successfully extracted and displayed at a museum in Canada, giving researchers and the public an up-close look at this natural wonder. It offered rare insight into the anatomy of these elusive giants, whose size makes them nearly impossible to study in the wild.
The heart of the blue whale is not just a vital organ—it’s a symbol of nature’s astonishing ability to scale life to incredible dimensions. From its slow, powerful beat to its human-swimmable arteries, it reminds us of how much there is left to explore and learn about the ocean’s most magnificent creatures.