Scientists have reported on February 28 that glow-in-the-dark amphibians may be far more common than thought suggesting that the ability to glow may help them identify each other in low light. Researchers from St. Cloud State University in Minnesota, Jennifer Lamb and Matthew Davis conducted a study exposing 32 species of the frogs, salamanders, newts and eels to blue or ultraviolet light and found that the creatures produced colourful patterns in a process called 'biofluorescence'. They found that the colourful patterns varied from specie to specie from blotches and stripes to glowing bones or sometimes all over fluorescence in different colours such as green, orange, and yellow, as per a new study published in Scientific Reports.
As per the study, some creatures even had fluorescent green skin secretions and urine. Biofluorescence is a process where organisms emit a glow after absorbing light energy. It occurs through various mechanisms with the presence of fluorescent proteins in skin and bones. The biologists believe that some of the amphibians have chromatophores, or pigment-containing and light-reflecting cells. The authors wrote that a lot of amphibians are nocturnal and live in dense forests. Scientists believe that the potential to glow may help them locate each other in the dark as their eyes have rod cells which are sensitive to green or blue light.
Biofluorescence also plays an important role to create more contrast between amphibians and their environment, allowing them to be more conveniently detected by other amphibians. In other species, the ability of glowing has been found to help creatures camouflage, signal themselves to potential mates, or even help them signal the appearance of the predators. Earlier the US researchers found that molecules responsible for allowing swell sharks to glow, indicating that it might perform functions other than identification, which includes fighting microbial infection.