What are respiratory pigments? What are some respiratory pigments and in which animal groups can each of them be found?
Respiratory pigments are molecules present in the blood that bind to oxygen transporting it to the tissues. In vertebrates the respiratory pigment is hemoglobin, reddish due to the iron of its composition. In crustacean and arachnid arthropods and in some molluscs the respiratory pigment is hemocyanin, blue due to the copper of its composition. Annelids have hemoglobin, hemerythrin and chlorocruorin as respiratory pigments.