Table of Contents (click to expand)It’s All About Evolution…But What’s The Reason?They’re Not The Only Ones… The blood of octopuses and squids is blue because they use a different protein for oxygen transport than human beings do. This protein, hemocyanin, relies on copper to bind with oxygen, which causes the blood’s discoloration. Squids and octopuses have adapted to their environment by changing the hemocyanin concentration in their blood. There aren’t many opportunities for human beings to interact with octopuses and squids, and most people are probably happy about that. These mysterious creatures of the deep are often depicted as sinister … Continue reading Why Do Squids And Octopuses Have Blue Blood?