There are certain creatures out there that do not bleed red, as we might expect. In fact, brachiopods and marine worms have violet blood. Certain types of mollusks, crustaceans and octopuses have clear blood that only turns blue when there’s oxygen around. Most backboned animals, including humans, have red blood because of the hemoglobin that has the role of transporting oxygen. However, this is not the case with all backboned creatures. A special group of lizards that only live in New Guinea and the Solomon Islands have blood that is lime-green.
Now, experts are trying to figure out why these little reptiles have such unusual blood and what led to its existence. Their genus is actually called Prasinohaema, which means “green blood” in Greek, and were first discovered rather recently, in 1969. However, nobody bothered to study them until a fascination with them hit Christopher Austin of Louisiana State University, a few decades later. What’s even more interesting, Austin says, is that these lizards also have green bones, tissues, muscles, mucosal lining and even tongue. It seems that this unusual color comes from a very high level of a green pigment called biliverdin.
The lizards that have green blood
Biliverdin actually forms when hemoglobin cells die. The liver extracts the iron from them, therefore creating this green waste product. Then, it gets transformed into something called yellow bilirubin. If the bilirubin levels are too high in the blood, it causes jaundice, that yellow skin we see in some people. In certain cases, it can even be fatal. Thankfully for them, these little lizards are not affected by it.
A new study, which the journal Science Advances recently published, offers more details about these lizards and their lime-green blood. As for the purpose of this anomaly, experts are not sure about it yet. The high levels of this substance might protect them from parasites. Still, tests are needed in order for this theory to be confirmed.
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