The Biofluorescent Secrets of Amazon's Frogs Revealed
The Amazon Rainforest, a vibrant canvas of greenery, hides a nocturnal spectacle. Recent research suggests that certain frogs in the region may not only thrive in colour during daylight but also use biofluorescence to emit a subtle glow at night as a form of communication.
These frogs, as revealed by a study involving researchers from Florida, Peru, Brazil, Ecuador, and Colombia, engage in biofluorescence. Using a spectrum of lights, researchers discovered that more frog species exhibit biofluorescence than previously known, expanding the list by 151 species.
Lead author Courtney Whitcher, a doctoral candidate in ecology and evolutionary biology, expressed the excitement of discovering a “glowing fluorescent world.” Every species examined demonstrated some level of fluorescence, suggesting a widespread phenomenon. Yup you read that right 100% of the species surveyed were biofluorescent!
Frog Vision
Frogs’ eyes are made of rods and cones, just like ours. Cones aid in seeing strong light and colors, whereas rods let us see in dim light. In contrast to humans and every other terrestrial animal, frogs possess two different kinds of rods that allow them to distinguish between colours in almost complete darkness. A greater number of rods are sensitive to green light, which enables them to detect even faint shining green, while some are tuned to blue light, which predominates in the evening. It follows that if a large number of these frogs are able to see green lights that other animals aren’t, then perhaps they are using green glows to convey, or at the very least, announce, their presence to one another.
All 151 species that they discovered had some form of fluorescence, ranging from bright spots on the back to splotches on the belly to full faces and limbs. Researchers discovered that the abundant blue of twilight is absorbed by frog skin and reflected back to equalize with the sensitivity of those green-sensitive rods in their eyes. It’s a double-edged vision. Furthermore, it occurs in a manner consistent with the ecology, activity, and ocular physiology of frogs.
Despite the progress, there’s still much to uncover about the secret lives of frogs. Whitcher notes the vast diversity of frog species, over 7,000 known, with only a fraction explored for biofluorescence.
Biofluorescence role in mating
As Whitcher continues her research, she focuses on the significance of fluorescence in mate selection. The study observed that strongly fluorescing body parts, often the undersides and throat, play a crucial role in communication and mate attraction. Is it possible that the frogs are using biofluorescent to communicate with each other? We still don’t know and more research needs to be done but it is a tantilising possibility.
Want to know more about the colourful world of Biofluorescence? Why not check out this article about Biofluorescence in Fish