Scientists have discovered another reason to admire him tardigrades; some of these microscopic, almost indestructible creatures wear a glowing “shield” that protects them from ultraviolet radiation.
Tubby tardigrades – also called moss piglets or water bears – are known for their hardness, resistance to extreme heat, cold and pressure, as well as space vacuum. They can also survive exposure to levels radiation will kill many other forms of life.
Today, scientists have discovered new clues about the radiation resistance of tardigrades. Experiments on tardigrades in Paramacrobiotus The genus states that fluorescence protects them like a layer of sunscreen, which replaces damage UV beam in harmless blue light, according to a new study.
Related: 8 reasons why we like tardigrades
Biofluorescence bathes diverse creatures in a terrifying radiance. It differs from bioluminescence, which illuminates light by a chemical reaction between compounds in the animal body; think of the bioluminescent glimmer made by fireflies, for example.
In fluorescent animals, their brightness ̵1; usually red or green – is not the result of a chemical reaction. Instead, these animals fluoresce when molecules inside their cells absorb light particles, or photons, from invisible UV rays and emit lower energy light into a lesser wavelength. There is turtle with fluorescent shells and heads, and small orange frogs at chameleons with fluorescent bones. Dikya glitter with fluorescent light, as it does scorpion, parrots, nematodes and yes – tardigrades, said the study’s lead author Sandeep M. Eswarappa, an assistant professor in the Department of Biochemistry at the Indian Institute of Science in Bangalore, India.
Yet little is known about how most fluorescent species use their glow. For the new study, the authors asked if fluorescence in tardigrades could be attributed to the radiation tolerance of water bears.
“Both phenomena are connected”
Scientists have tried Paramacrobiotus UV resistance of tardigrades by exposing them to 15 minutes of radiation at levels high enough to kill most microorganisms. All of Paramacrobiotus tardigrades are still alive after 30 days, while Hypslbius pattern UV-sensitive tardigrades all died within 24 hours of radiation exposure, according to the study.
“There is no difference in the survival of these two species of tardigrade without them being treated with UV radiation,” Eswarappa told Live Science in an email.
Paramacrobiotus the tardigrades also shone brightly when exposed to UV light. However, when researchers obtained fluorescent components from Paramacrobiotus tardigrades and applied them to both H. pattern and the nematode Caenorhabditis elegans – which is also not fluorescent and UV sensitive – the two species “showed slight tolerance to UV radiation,” the researchers reported.
“It is normal to think that both phenomena are connected,” Eswarappa said.
Previous studies suggest that biofluorescence may offer UV protection in some corals, and researchers hunting for extraterrestrial life suggest that biofluorescence may help organisms thrive and live in distant worlds orbiting red dwarf stars – which have higher UV output than our sun – potentially many planets with many variations of bright creatures, Live Science was previously reported.
For shining Earthbound tardigrades, fluorescence could increase their chances of surviving in habitats where water bears are often exposed to the sun, Eswarappa said.
“UV resistance gives tardigrades the ability to thrive in environments with a high UV index. For example, in tropical regions,” he said.
The findings were published online October 13 in the journal Biology Letters.
Originally published in Live Science.