They're tiny, brightly colored, and poisonous, but they glow for attention - that's what these frogs do.
He is about to end up run over, his mother saves himThere are those who use sounds, those who give off hormones (or pheromones) and those who shine to attract attention: this is what tiny (and poisonous) brightly colored frogs do, which, in the mating season, become fluorescent. The discovery is the work of a research group from NYU Abu Dhabi.
Shining with their own light to attract a mate: these frogs (scientific name Brachycephalus ephippium), which live in Brazil (and are already threatened by the loss of their habitat), really do. They roam the forest during the mating period, buzzing, but the call is not acoustic but visual. The their skeleton becomes fluorescent.
A casual discovery that made at NYU Abu Dhabi: in fact this singular ability is not visible to the naked eye. The researchers were convinced that the frogs were trying to attract potential mates with their call, but then they realized that this could not be heard.
For this reason, after several hypotheses, they illuminated these tiny amphibians (from 12.5 mm to 19.7 mm in length) with ultraviolet light, noting that their backs were illuminated: the frogs therefore become fluorescent, and this is the signal of "availability" . In fact, light is not visible to the human eye, but to that of frogs, yes.
On the other hand, it is not even the first species to implement such a mechanism biofluorescence: recently, for example, a research group at the Ludwig Maximilian University of Munich demonstrated that the skeleton of chameleons glows in the dark and believes that this ability is used for communication and for sexual selection.
In particular, for these frogs, scholars report that the fluorescence (the ability to re-emit light of other wavelengths after irradiation) is due to bony plates that lie directly under a very thin skin. In reality, the entire skeleton has this property, which however is visible only externally, where the layer of skin tissue above the bones is very thin (about seven micrometers thick).
Foto: Scientific Reports
Furthermore, the lack of pigmented cells typical of dark skin (which block the passage of light) and the thin thickness of the skin allow ultraviolet light to cross and irradiate the bone plates, which then re-emit incredible colors.
"The fluorescent motifs are visible to the human eye only under a UV lamp - explains Sandra Goutte, first author of the research - In nature, if they were visible to other animals, they could be used as intraspecific communication signals [...], warning potential predators of their toxicity. However, more research on the behavior of these frogs and their predators is needed to identify the potential function of this unique luminescence".
Not just "love" then. Frogs may also light up to defend themselves from predators. Or who knows, nature may have "invented" this strategy as a control mechanism, because even prey could be alerted to the presence of this very poisonous frog.
All very soon to tell. But not to stop surprising us.
The work was published in Scientific Reports.
Read also:
- Smallest frogs ever discovered. And they are really tiny
- Frogs face mass extinction: the shock study
Foto: Sandra Goutte / NYU Abu Dhabi
