Question from the reader – Robson Vilanova Ilha,
Sao Sepe, RS
No. Most vertebrates have red blood, but there are exceptions. The frog Chiromantis samkosensis, some marine fish (such as Clinocottus analis) and lizards of the genus Prasinohaema have green blood! By the way, these lizards are a special case, since, in addition to hemoglobin (a protein in red blood cells that transport oxygen), they have biliverdin, which is green in color, running through their veins. Most invertebrates, whose circulatory system is open, have a fluid called hemolymph with a function similar to that of blood. Some insects, molluscs (like the octopus) and arthropods (like the tarantula) have blue hemolymph thanks to the presence of another substance that carries oxygen: hemocyanin, which is blue in color. And the sanguine color palette does not end there: in nature there is yellow, orange and even colorless blood.
SOURCES Articles Green-Blood Pigmentation in Lizardsby Christopher C. Austin and Kevin W. Jessing, Parasites in a Biodiversity Hotspot: a Survey of Hematozoa and a Molecular Phylogenetic Analysis of Plasmodium in News Guinea Skinksby Christopher C. Austin and Susan L. Perkins, and The Blue-green Blood Plasma of Marine Fish, by Lee-Shing Fang and Jeffrey L. Bada; site fauna-flora.org