Some frogs glow at dusk, using a fluorescent compound, scientists say
In 2017, scientists announced a natural miracle, some frogs glow at dusk, using a fluorescent compound that we have not seen before in nature.
At the time, it was not known how many species of frogs could emit this fluorescence.
A study of 151 species of South American frogs shows the degree of fluorescence of each individual species. Data from the study suggest that fluorescence is tied to the frogs’ vision.
According to scientists, light emission affects the way frogs signal to each other. They believe that fluorescence repels predators.
“Through a field study in South America, we discovered and documented patterns of biofluorescence in tropical amphibians,” writes Florida State University biologist Courtney Witcher.
“Many things in the animal kingdom glow, but the reason is not always obvious,” scientists point out.
Fluorescence is a type of glow created when light is absorbed and re-emitted at a different wavelength, and is seen in many species, including sharks, chameleons and salamanders. Bones also fluoresce, scientists explain.
The biofluorescence produced in the skin of frogs is different from the fluorescence of other luminous animals.
Blue light, which is closest to Earth’s natural twilight, produces the strongest fluorescence, and the fluorescence itself appears primarily in two distinct peaks of visible light — green and orange, the scientists said.
Many frogs are crepuscular – that is, they are active at dusk. In some species, their eyes are designed to work best in this light, dominated by rod-shaped photoreceptors sensitive to green and blue, writes Science Alert.
Frogs’ green glow is brightest during the day, scientists explain. The parts of the body that glow are those most involved in animal communication, namely the throat and back. This suggests that biofluorescence is part of the communication toolkit of frogs.
Source: Science Alert
Illustrative Photo by nastia: https://www.pexels.com/photo/green-frog-103796/
