So what makes these intelligent sea creatures so adaptable? Skill is literally in his blood. The same pigment that gives octopus blood its blue color, hemocyanin, is responsible for keeping the species alive in extreme temperatures. Hemocyanin is a blood-borne protein that contains copper atoms that bind to an equal number of oxygen atoms. It is part of the blood plasma of invertebrates.
More primitive species (such as octopus, squid, and several other invertebrates) use a different protein, called hemocyanin, which is based on copper, rather than iron, as the binding mineral of choice. When copper binds with oxygen, the discoloration is different, which results in the blue color of your blood. Society's elites aren't the only ones with blue blood. Several species of octopus have blue, rather than red, liquid that runs through their veins.
Researchers suspect that adaptation to blue blood is the result of the octopus's inability to migrate away from difficult environmental conditions. The brain power of the octopus is not easily evident at first glance, but it has been shown to be able to plan, reason and predict sports matches. The pigment in chromatophores is usually only red, yellow, or brown, but many species of octopus are capable of producing even more colors. Therefore, the immediate availability of copper may have caused this halt in the evolutionary progress of squid and octopus, since their environment provided a wealth of that essential mineral, leaving the rest, as they say, to evolutionary history.
There are a lot of fascinating facts about how octopus looks and works, but there is another one hidden just below the surface. Crawling across the ocean floor isn't the fastest way to get around, and with an average lifespan of 5 to 15 years (octopus and squid at both ends, respectively), long-distance migration simply doesn't make sense. The octopus is able to stretch these sacs using muscles that span the chromatophores, which makes the pigment more or less visible on the surface of its skin. Now, the interesting thing is that hemocyanin plays a key role in the adaptations of squid and octopus to their environment.
Copper-rich blood is not acceptable for an octopus under all conditions, which is an impediment to the animal moving everywhere. But for the Antarctic octopus Pareledone charcoti, oxygen transport through hemocyanin poses problems at sub-zero temperatures. Octopuses have three hearts and need more oxygen than most other invertebrates, so hemocyanin allows octopuses to obtain a constant supply of oxygen, even when it is not available in their environment. The ocellated icefish, for example, can brush their fins with the Antarctic octopus in the same cold habitat, but their blood is very different.
While octopus can swim in some way, as mentioned above, they prefer to throw themselves on the ocean floor. This level of cognition and complexity has left many people uncomfortable with the idea of eating octopus and others to speculate that they may have the minds of living beings closer to a human level of intelligence.