Why Do These Lizards Have Toxic Lime-green Blood?

  • Why Do These Lizards Have Toxic Lime-green Blood?

Why Do These Lizards Have Toxic Lime-green Blood?

And scientists have been trying hard to figure out what benefit this characteristic - caused by high levels of an ordinarily toxic green bile pigment - may give them.

Moreover, green-blooded skinks likely evolved from a red-blooded ancestor, the researchers found.

Basically, the green coloured blood is formed in the lizards due to the high levels of bile pigment in their body which is toxic in nature.

A pair of LSU scientists has found the biological cause of odd, lime-green blood found in several species of New Guinea lizards could unlock cures for malaria and jaundice in humans, according to an LSU news release. However, even though animals in the Prasinohaema genus have levels of biliverdin that are 40 times greater than the lethal concentration in humans, the skinks are surprisingly healthy, the researchers said.

"Understanding the underlying physiological changes that have allowed these lizards to remain jaundice-free may translate to non-traditional approaches to specific health problems", Rodriguez concluded.

"In addition to having the highest concentration of biliverdin recorded for any animal, these lizards have somehow evolved a resistance to bile pigment toxicity", Rodriguez said.

But the lizards discovered in this region are showing some new secrets about them, which includes how they evolved.

"Oh, these animals are gorgeous, truly some of the most lovely and enigmatic lizards in the world, living on one of the most megadiverse islands on the planet", Austin said.

Their findings show the green blood evolved from red blood independently four separate times in lizards in separate genetic lineages-debunking the assumption that all green-blooded lizards must belong to one closely-related group. This suggests that green blood might have been an adaptive reaction, but researchers can not tell why the process had occurred.

For the study, they analyzed 51 skink species living in Papua New Guinea.

The green-blooded critters mainly live in lowland tropical forests and, according to Reuters, grow to be up to a foot (30 cm) long. Another supposition is that biliverdin acts as an antioxidant, purging their system of free radicals known to cause a large number of diseases. "Ongoing work with the Austin lab examines the potential effect of the green blood pigment on malaria and other parasites that infect these lizards", said co-author Susan Perkins, curator and professor at the Sackler Institute for Comparative Genomics and the Division of Invertebrate Zoology, American Museum of Natural History. Several fish, frog and insect species also are green-blooded. Note: material may have been edited for length and content.

Rodriguez is lead author of a new study, to be published in the journal Science Advances, looking into the evolutionary history of green blood.