Mammals That Glow Under a Blacklight
This time, we’re taking a look at mammals that glow under blacklight, exhibiting bioluminescence. These mammals can fluoresce, absorbing light in one color or wavelength and emitting it in another.
Of these rare mammals that glow, there are colors in every shade of the rainbow. However, scientists don’t know why or how they do it.
If you had to guess which mammals glow under a blacklight, what would you say? Well, it seems only fitting that one of the strangest mammals in the world has recently discovered to glow: the platypus.
Add it to the long list of traits, which makes the platypus incredibly strange. It’s venomous, egg-laying, and has a bill like a duck. Now, we can also confirm it glows blue-green under UV light.
Let’s take a closer look at the bioluminescent mammals that glow known so far. They are all small, furry creatures that shine with incredibly bright colors under ultraviolet light.
Hot Pink Flying Squirrels Discovered by Chance
Researchers from Northland College, WI, and Colorado State University released a study into bioluminescent platypuses in October 2020. The discovery came by chance. Professor Jonathan Martin played around with a UV flashlight behind his house one night and discovered a bright pink flying squirrel at a birdfeeder.
“Perhaps the stars aligned that night because a flying squirrel glided right through the view of his blacklight,” explained student Allie Kohler. “He came to school the next day saying, ‘there’s hot pink glow-in-the-dark flying squirrels in my back yard!'” (see video below)
From there, the researchers went to a museum in Chicago to examine preserved flying squirrels. To their amazement, the specimens all glowed bright fluorescent pink under UV light. However, non-flying squirrels didn’t glow.
Nobody Knows Why the Platypus Glows
While they were at it, another professor, Erik Olson, suggested trying out the UV light on something totally different for comparison.
“Like, what about platypuses? That’s kind of as far from flying squirrels as you can get,” said Olson.
Sure enough, the platypus specimens glowed but in a different color: blue-green. As fascinating as the find is, the researchers don’t know why these animals glow.
For one, they don’t know if platypuses see the glow themselves. For another, there seems to be no clear purpose. One idea is that it helps them to hide from predators that are sensitive to UV light.
Related: The Rare and Not-So-Rare Fascinating World of the Chimera
Mammals That Glow from Three Lineages
After discovering the glowing platypus and flying squirrels, the researchers noted research from the 80s. In 1985, other researchers found out that opossums, which are marsupials, glow in a rainbow of colors.
Below, you can see a short-tailed opossum glowing red under a blacklight.
A Missing, Glowing Link?
Opossums are marsupials with a pouch to temporarily hold their babies. However, the platypus is an egg-laying mammal in the monotreme group, while the flying squirrel is in the placental mammal group. Interestingly, a flying squirrel is more closely related to primates (like ourselves) than to marsupials like the opossum.
Nevertheless, these three mammal lineages all share the strange bioluminescent trait. However, they don’t share the same diet and have different ecosystems. These creatures share one trait in common: they tend to hunt at night or in low light conditions. Therefore, they might fluoresce to communicate or for better night-time perception.
One wildlife biologist from Virginia Tech, Corinne Diggins, suggests the fluorescent colors could be a way to attract mates.
“Maybe a brightly pink fluorescent belly on a male flying squirrel makes a female swoon,” Diggins says.
As Kohler points out, since they all share this trait, it’s a possible sign it passed down through evolution. However, the mechanism that causes the fluorescence remains, for now, a mystery.
See more from Ph.D. ecology student Allie Kohler from Colorado State University:
A Call to Save the Platypus from Extinction
Today, Australian scientists are calling to list the platypus as a vulnerable species. Over the last 30 years, the aquatic habitat the species requires has shrunk by more than a fifth. Climate change has ravaged Australia, bring devastating droughts. Other problems include dam building, clearing land for farming, and lower oxygen levels in waterways.
Hopefully, the platypus can avoid extinction as it’s one of the worlds’ most incredible mammals: one of the very few mammals that glow.
More about the platypus from CNA:
Featured image: Screenshots via YouTube/ Allie Kohler from Colorado State University