In March 2017 a team of Argentine and Brazilian scientists announced that they had found a treefrog that naturallyfluoresces, the first knownamphibian to do so. The polka-dottree frog (Hypsiboas punctatus) is a small frog about 3 cm (1.2 inches) in length that lives in theAmazon basin. Its coloration is a drab green, with reddish, white, or yellow spots or stripes, but underultraviolet light it glows a bright fluorescent green.

In fluorescence, light is absorbed and then reemitted. Many sea creatures fluoresce, but among land animals, only someparrots andscorpions do this. (Creatures such asfireflies arebioluminescent and generate their ownlight throughphotochemical reactions without having to absorb it first.)

Interestingly, themolecules that the polka-dot tree frog fluoresces with have been previously seen only inplants, and the frog is quite bright in fluorescence, shining about 18 percent as bright as the fullmoon. The scientists planned to study the frog’s eyes to see if it can detect its own fluorescence and other related species of frogs to see if they have the same ability.