Scientists have discovered the world’s first known naturally fluorescent amphibian — the South American polka-dot tree frog.
The finding happened very much by accident. Researchers at the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires, Argentina were studying a pigment in the frog, a common species found throughout the Amazon basin, when they noticed it glowed greenish-blue under UV light.
Polka-dot tree frogs measure about 3 centimeters long, are pale green with white or reddish spots, and are active mostly at night. The scientists traced the frogs’ ability to glow to three molecules — hyloin-L1, hyloin-L2, and hyloin-G1 — located in the lymph tissue, skin, and glandular secretions. The fluorescence increased the frogs’ brightness, or glow, by 19 percent at night with a full moon, and 30 percent during dusk. The scientists, who published their findings recently in the journal the Proceedings of the National Academy of Sciences, say they aren’t sure exactly what function the frogs’ fluorescence serves, but that it could play some role in communication.
Previously, scientists knew of several ocean creatures — including some corals, fish, and sharks — which could fluoresce. On land, however, the only animals known to do it were parrots and some scorpions.