There is a type of skink, called Prashinohaema, which lives in one island of New Guinea, that has green blood, bones and tongue, and even tissue.
But no one knows why. Scientists are trying to figure out why this lizard has such peculiar features.
A Louisiana State Univ. scientist, Prof. Austin, began to solve just that riddle in 1969. The skinks are particular to the island of New Guinea. The island is somewhat far from others and may have provoked a genetic singularity, much like other land masses that are far away from others. Or maybe the feature is simply adaptive to an external factor present in the island. In other words, it is an evolutionary change and not just a selective one present from the beginning of the existence of that species.
As he began studying the lizards, prof. Austin discovered that the lizards had a much higher than normal concentration of biliverdin, which like bilirubin is a bile pigment, that made all fluids and most tissues, green.
In humans, both bilirubin and biliverdin are present as a byproduct of the hepatic breakdown of hemoglobin after its life span ends. But in humans such pigments leave the body through the intestines, and are present in minute quantities.
What makes the mystery even more extraordinary is that biliverdin in high concentrations in the blood is extremely toxic. In humans they are responsible for jaundice, which can in some cases lead to death.
What the scientist thinks, is that the biliverdin became tolerated by this species as a means to ward off a deadly parasite called Plasmodium. This parasite is what causes malaria in humans. Malaria affects birds and reptiles alike, since the last two have the same genetic root. The biliverdin then, inhibits Plasmodium infections.
By comparing Prasinohaema skinks to a closely related lizard, which has red blood, the scientist will next try to understand the genomial difference between the two.
Source : nat Geo/ 10.1.13
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