Strange lizard species with blue blood, beyond scientific understanding

(Dan Tri) - Prasinohaema lizards can live healthily because they possess characteristics that are different from most terrestrial animals.

Strange lizard species with dark blue blood (Photo: Getty).

When we think of blood, most of us immediately think of the dark red liquid associated with life.

However, the animal world doesn't quite follow that rule. Hidden in the dense forests of New Guinea and the Solomon Islands, there is a group of lizards of the genus Prasinohaema with a strange feature: their blood is green.

What is special is that they are the only amniotes known on Earth to have blue blood, and until now scientists have not been able to fully explain why this characteristic formed and maintained during evolution.

Prasinohaema are arboreal, insectivorous skinks that don’t look much different from other familiar lizards. They have long bodies, small scales, and slender limbs.

But inside, their biology is completely different. The unusual blue color of their blood is caused by extremely high concentrations of biliverdin – a blue pigment produced during the breakdown of red blood cells.

Prasinohaema lizard blood (below) compared to normal blood types (Photo: Nat Geo).

In humans and most mammals, biliverdin accumulation is often seriously harmful, leading to jaundice and even death if concentrations become too high.

Yet, the Prasinohaema lizards live healthy lives with plasma biliverdin concentrations 40 times higher than those of people with jaundice. Not only their blood, but also their bones, muscles, soft tissues, tongues, mucous membranes... are dyed a characteristic blue color.

The question is, what survival advantage does this strange trait of blue blood give the Prasinohaema lizard?

Scientists believe that this is not a random phenomenon, because signs of independent evolution have been recorded at least four times in the same species group. This proves that blue blood must have some adaptive value, possibly related to the ability to fight parasites or a special effect in physiology.

However, direct evidence for this remains limited to date.

That was until a new step forward was taken when scientists at Brigham Young University (USA) announced the decoding and annotation of the first genome of the Prasinohaema species.

They used a museum specimen that had been stored for more than 20 years, originally identified as Prasinohaema flavipes, but now possibly a new species. Genome analysis revealed the presence of a highly mutated version of alpha-fetoprotein (AFP), a protein known to be found in mammals.

Hypothesized, this AFP could bind to biliverdin, allowing the toxic pigment to remain in the blood without causing cellular damage. If true, this would open up a whole new biological mechanism that could help explain why these lizards not only survive, but thrive.

However, the research is still in its early stages. Scientists stress that more data is needed to understand how the Prasinohaema genome has adapted to biliverdin, as well as the true ecological benefits that blue blood brings.

The discovery of this lizard species promises to open up a new treasure trove of knowledge for humanity, possibly answering evolutionary mysteries, while also revealing potential medical applications in treating diseases related to bile pigment accumulation in humans.

Source: https://dantri.com.vn/khoa-hoc/ky-la-loai-than-lan-co-mau-xanh-nam-ngoai-hieu-biet-cua-khoa-hoc-20250911085125484.htm