We are all used to blood being scarlet red, but some creatures seem to have it colored in odd shades. A strange genus of skink belonging to the species Prasinohaema has strange green blood that has incredibly toxic properties. This surprised the researchers, who decided to investigate the matter and disclose the mystery of the green blood.
Why do the strange lizards have green blood?
These strange skinks seem to be really fond of the color green. Not only their blood has this color, but also their tongue, bones, and muscles. This happens as their entire bodies have high concentrations of biliverdin. You might have heard of the substance, as it’s present in our organism as bile pigment.
Biliverdin appears whenever hemoglobin, the particle that transports oxygen, breaks down to produce bilirubin, another bile pigment. We only have low levels of biliverdin in our bodies, and we can spot it at the surface whenever we get hurt and develop bruises. However, too much of the pigment can be really dangerous.
This is exactly why we should stay away from the odd lizard. Its green blood and body contains 40 times the concentration of biliverdin that is enough to kill a human. Therefore, this tiny creature is extremely toxic. However, researchers were curious how these creatures could survive the toxic chemical.
The creatures somehow evolved a resistance to the toxicity of the pigment
For the study, they analyzed 51 skink species living in Papua New Guinea. This is how they realized they somehow managed to evolve a resistance to the high toxicity of biliverdin. The pigment might have caused them to have green blood and green bones, but they became immune to developing adverse reactions to it.
The genetic analysis of the lizards showed there are four different groups of skinks with green blood. They all evolved separately but had a common ancestor with red blood. This suggests that green blood might have been an adaptive reaction, but researchers cannot tell why the process had occurred. The pigment might work somehow as an antioxidant and protect the creatures from infection.
The study in question was published in the journal Science Advances.
Image source: Wikimedia Commons