Here’s something you probably don’t know: Octopuses have three hearts, and two of them stop beating when they swim.
The two branchial hearts pump blood to the gills, while the systemic heart pumps it to the rest of the body. When an octopus swims, the systemic heart actually stops beating, which is why octopuses prefer to crawl rather than swim — swimming is exhausting and essentially leaves them temporarily short of oxygen.
Here’s something many people don’t know: Octopuses have three hearts, and two of them stop beating when they swim.
The two branchial hearts pump blood to the gills, while the systemic heart pumps it to the rest of the body. When an octopus swims, the systemic heart actually stops beating, which is why they prefer to crawl — swimming is exhausting and quickly tires them out.
Here’s something most people don’t know:
Octopuses have three hearts, and two of them stop beating when they swim.
When an octopus crawls along the ocean floor, all three hearts pump blood. But when it swims—by jetting water through its siphon—the two branchial hearts (which send blood to the gills) actually stop beating. This makes swimming so exhausting that octopuses prefer to crawl whenever possible. They only swim when they really need to escape or move fast.
And here’s the kicker: their blood is blue, because it uses copper-based hemocyanin to carry oxygen instead of iron-based hemoglobin like ours. That’s why they’re so sensitive to water temperature and oxygen levels.