In a study, a team of South American researchers recounts their discovery: the first case of fluorescence observed in one of the 7,600 species of amphibians known to date, an “incredible” capacity for luminosity in the dark.
Already observed in many terrestrial and aquatic species, the phenomenon of fluorescence was observed for the very first time in an amphibian species. This is theHypsiboas punctatusa South American tree frog and it is a discovery that we owe to a team of researchers from the same continent.
This species of frog consists of specimens that can be green, yellow or red and scientists have discovered that they illuminate greenish blue when found in the dark. However, this is fluorescence and not bioluminescence. This means that they do not light up in complete darkness since fluorescence involves prior absorption of a source of light.
In their study published in the journal PNAS, the researchers explain this phenomenon by the presence in this species of fluorescent molecules never before observed. Called hyloin-L1, hyloin-L2, and hyloin-G1, these molecules show up in the lymphatic tissue, skin, and glandular secretions of these amphibians. They offer these frogs an incredible capacity for luminosity in the dark, namely a fluorescent emission equivalent to approximately 18% of that emitted by a full moon.
From now on, it will be a question for them of testing the possible capacities of fluorescence of 250 species of arboreal frogs close phylogenetically to Hypsiboas punctatus, as well as to try to discover if the latter present photoreceptors sensitive to fluorescence. If this were the case, this recently discovered fluorescence phenomenon could mean that it is a means of communication between specimens, for example to attract a sexual partner in the context of reproduction.