![Michael English on Twitter: "From the archives, a vial of giant octopus blood! That blue colour is caused by the presence of the copper rich protein haemocyanin. (Note, the octopus had died Michael English on Twitter: "From the archives, a vial of giant octopus blood! That blue colour is caused by the presence of the copper rich protein haemocyanin. (Note, the octopus had died](https://pbs.twimg.com/media/Ek2ZyMTXUAIW1hL.jpg)
Michael English on Twitter: "From the archives, a vial of giant octopus blood! That blue colour is caused by the presence of the copper rich protein haemocyanin. (Note, the octopus had died
![David Steensma, MD on Twitter: "An octopus, in contrast, has genuinely blue blood. Octopi use hemocyanin as a respiratory pigment (so do some other mollusks). Hemocyanin is copper-containing, cell-free, a brilliant sapphire David Steensma, MD on Twitter: "An octopus, in contrast, has genuinely blue blood. Octopi use hemocyanin as a respiratory pigment (so do some other mollusks). Hemocyanin is copper-containing, cell-free, a brilliant sapphire](https://pbs.twimg.com/media/EbXJushWsAEOHVz.jpg)
David Steensma, MD on Twitter: "An octopus, in contrast, has genuinely blue blood. Octopi use hemocyanin as a respiratory pigment (so do some other mollusks). Hemocyanin is copper-containing, cell-free, a brilliant sapphire
What is an octopus's blood color? How is an octopus's blood color different from other animals? - Quora
![Business for Development on Twitter: "#FunFact: Why is octopus blood blue? The blue pigment, hemocyanin, is responsible for keeping the species alive at extreme temperatures. Hemocyanin is a blood-borne protein containing #copper Business for Development on Twitter: "#FunFact: Why is octopus blood blue? The blue pigment, hemocyanin, is responsible for keeping the species alive at extreme temperatures. Hemocyanin is a blood-borne protein containing #copper](https://pbs.twimg.com/media/D73shBFUYAE1vxu.jpg)
Business for Development on Twitter: "#FunFact: Why is octopus blood blue? The blue pigment, hemocyanin, is responsible for keeping the species alive at extreme temperatures. Hemocyanin is a blood-borne protein containing #copper
![An octopus' blood is blue due to the protein called, haemocyanin, which carries oxygen around its body, contains copper rather than iron like we have in our own haemoglobin. The copper-based protein An octopus' blood is blue due to the protein called, haemocyanin, which carries oxygen around its body, contains copper rather than iron like we have in our own haemoglobin. The copper-based protein](https://i.redd.it/0qcbp4ayv44a1.jpg)