If you were to host a blacklight party in the taxidermy wing of a natural history museum, most mammals would be a perfect fit for its eerie fluorescent glow.
This is what Kenny Trabouillon, curator of mammals at the Western Australian Museum, discovered when his team exposed 125 species of mammals in its collection to ultraviolet light.
This luminous effect was not limited to platypuses and wombats, which were identified as biofluorescent species several years ago. All the species of mammals they examined emitted shades of green, blue, pink, or white under ultraviolet light.
The insides of the red fox’s pointed ears have turned a shocking fluorescent green.
The polar bear glowed like a white T-shirt under a black light, and so did the zebra’s white stripes and the leopard’s yellow fur.
The orange leaf-nosed bat’s wings turned into a pure white skeleton, and its fur glowed pink.
And the ears and tail of the great bilby shone “as brightly as diamonds” like a travillon. Listed in 2020.
This study showed that fluorescence is present in half of the mammalian families, nearly all clades, and all 27 orders.
“We found that fluorescence is widespread among mammalian taxa,” the researchers said. write. “Area of fluorescence included bright white fur, quills, whiskers, claws, teeth, and some bare skin.”
The only mammal without external fluorescence was the spinner dolphin. Only the teeth were fluorescent.
fluorescence created When chemicals such as proteins absorb ultraviolet light and emit light at longer wavelengths.
has been observed in coralsea turtle, frog,Scorpion, Momonga of the New World, parrot, rabbit, human, dormouse.
biologists are has been discussed for a long time Does this fluorescence confer an evolutionary advantage, or is it simply a byproduct of surface chemistry?
“It remains unclear whether fluorescence plays any specific biological role for mammals,” the researchers said. write.
A protein called keratin, found in nails, skin, teeth, bones, rachis, whiskers, and fingernails, is biofluorescent, but this optical property may simply be an evolutionary coincidence. Keratin causes fluorescence even in unpigmented or light-colored hair.
The southern marsupial mole (Notoryctes typhlops) was one of the most fluorescent mammals due to its yellow-white fur. However, this species lives underground.
The keratin inside N. typhlops’ Researchers say the fur may be raised to protect it from abrasive soil particles, which can have fluorescence as a side effect. make a hypothesis.
Similarly, it seems unlikely that fluorescence would promote survival in bats that rely on echolocation instead of vision to navigate and hunt.
Although there were many skepticismthere was some evidence that fluorescence is evolutionarily advantageous in some mammals.
When researchers observed fluorescence in pigmented fur, this suggested that chemicals other than keratin were producing the effect. fluorescent dye.
Mammals that are most active at night, dusk, and dawn may use fluorescence to help them stand out in the dark, for mating or to protect territory.
“Fluorescence was most common and strongest among nocturnal species,” the researchers said. writes.
platypus Hunt underwater with your eyes closedTherefore, their glowing abdominal fur is unlikely to be a useful visual cue.
However, this may be a kind of camouflage. counter shadingfound in many aquatic animals.
Alternatively, platypuses may absorb ultraviolet light rather than reflect it to hide from predators and prey that can see ultraviolet wavelengths.
Whether there is an evolutionary advantage or not, this is an interesting phenomenon.
This study Royal Society Open Science.
