Researchers at a zoo in Ohio have found that Tasmanian devils—carnivorous marsupials native to the Australian island state after which they are named—glow under ultraviolet light. They shared a stunning picture of their discovery.
A team from Toledo Zoo said they had documented the first case of a phenomenon known as "biofluorescence" in the animals. This refers to when living organisms absorb light and re-emit it at a different wavelength.
"In the case of the Tasmanian devil, the skin around their snout, eyes, and inner ear absorbs ultraviolet (UV) light—a type of light that is naturally abundant, yet invisible to humans—and re-emits it as blue, visible light," a post on the Toledo Zoo Facebook page read.
Scientists have previously documented biofluorescence in some plant, insect, marine and bird species. One 2001 study found that some bird species use biofluorescence to attract mates, while a 2014 paper documented fish using this trait to camouflage themselves.
The phenomenon in mammals is rare with only a handful of documented cases, including in Virginia opossums and southern flying squirrels—which are both native to North America.
But over the course of 2020, scientific papers have been published documenting biofluorescence in other Australian mammals, such as platypuses and wombats.
Inspired by these recent findings, the team at Toledo Zoo decided to see if they could observe the phenomenon in the Tasmanian devils resident at the site.
"When platypuses were recently found to be biofluorescent, it got us pretty excited to try and discover this in other animals, especially in Australian mammals," Jacob Schoen, a researcher at the zoo told ABC News.
The team shone UV light on the marsupials and were surprised to find that they could see the phenomenon on their first attempt.
"It was pretty shocking when we saw it, we went into it not expecting much and it was pretty exciting," Schoen said.
While the findings are intriguing, the researchers said it is unclear whether the biofluorescence serves any ecological purpose, or if it is simply "happenstance."
"While it is possible that Tasmanian devils evolved biofluorescence for purposes such as those above, it is also possible—though perhaps less exciting—that due to their primarily nocturnal habits, they may not encounter fluorescence-inducing levels of UV in the wild," the Facebook post read.
"Additionally, Tasmanian devils or other species they interact with—such as their predators or prey—may not be able to detect UV light or the resulting fluorescence."
In order for the biofluorescence to be considered a functional adaptation, scientists would need to demonstrate that the trait influences the behavior of the animals.
