The blood of an octopus is blue. This unique color comes from a copper-rich protein called hemocyanin, which is used for transporting oxygen in their bodies. Unlike the hemoglobin in human blood, which contains iron and gives blood its red color, hemocyanin turns blue when it binds to oxygen. This adaptation allows octopuses to survive in the cold, low-oxygen environments of the ocean where they often inhabit.
In essence, the blue color of octopus blood is an evolutionary trait that helps these fascinating creatures thrive in their aquatic world. It’s a striking example of how different life forms adapt to their environments in distinct and interesting ways.