Here's something that might surprise you: octopuses have three hearts. Two pump blood to the gills, while the third pumps it to the rest of the body. Even stranger—the heart that delivers blood to the body actually stops beating when the octopus swims, which is why they prefer crawling along the ocean floor instead. Swimming is exhausting for them.
Here's something that might surprise you: octopuses have three hearts—two pump blood to the gills, while the third pumps it to the rest of the body. And weirdly, the heart that serves the body actually stops beating when the octopus swims, which is why they prefer crawling along the ocean floor. Swimming exhausts them so much that they avoid it when possible.
Here's something that might surprise you: octopuses have three hearts and blue blood.
Two hearts pump blood to the gills, while the third pumps it to the rest of the body. Their blood is blue because it uses copper-based hemocyanin to carry oxygen instead of the iron-based hemoglobin that makes our blood red.
Even stranger: when an octopus swims, the heart that delivers blood to the body actually stops beating. This is why they prefer crawling along the seafloor—swimming exhausts them rapidly.