Researchers at the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires accidentally found the special species while they were studying polka dots tree frogs, a species common in the rain forest.

The skin colour of new discovered species of frog stays dull brown with red polka dots when placed in normal light, and transforms into bright green when exposed to UV lights.

The researchers, who published their discovery on March 13 in Proceedings of the National Academy of Sciences, found that the trait enhanced the brightness of the frog by 19-29% depending on the level of ambient light in its surroundings.

The compound causing the blue–green glow of the polka-dot tree frog was not previously thought to exist in vertebrates and its discovery has excited researchers.

“This is very different from fluorophores found in other vertebrates, which are usually proteins or polyenic chains,” Maria Gabriella Lagoria, a photochemist at the University of Buenos Aires and study co-author, told Chemistry World.