Tardigrades are microscopic animals capable of living in extreme conditions, with freezing temperatures, exposure to radiation, dehydration and even in the vacuum of space. Recently, a new species of tardigrade has been discovered: individuals glow blue when exposed to ultraviolet light. According to scientists, the specimen uses fluorescence as a protective shield.
Even more resilient
There are about 1300 different species of these creatures inhabiting all regions of the planet. The tardigrade in question has a natural fluorescence, which manifests itself in a blue glow when exposed to ultraviolet light. In a new study, researchers are suggesting that this fluorescence protects tardigrades from levels of ultraviolet radiation, which can kill other microorganisms, such as bacteria and viruses.
In the new study, scientists removed these creatures from the moss that grew on a wall in Bangalore. With a germicidal lamp, scientists used ultraviolet light to test the creatures’ tolerance. The first doses eliminated most individuals of the species Hypslbius pattern, but after 24h all individuals of this species died.
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However, a group of tardigrades with reddish-brown spots managed to survive for 30 days after a dosage that kills bacteria and worms in just five minutes. By further increasing the dose, 60% of those tardigrades managed to survive for another 30 days. Due to the enormous resistance of the animals, the scientists saw that it was a new species.
The next step was to use an inverted fluorescence microscope, which then caused the beings to emit blue light. The scientists then suspected that the fluorescent pigments in the skin of tardigrades could be linked to resistance to ultraviolet. Therefore, they covered individuals of the species Hypslbius pattern with the pigments of fluorescent beings, and once again exposed them to the lamp. The result, finally, was a “shield” formed over individuals of the species H. pattern, who survived almost twice as long as when unprotected.
Thus, the new study shows that there is, in fact, a demonstration of fluorescence photoprotection by the new species discovered. In other words, this fluorescence protects tardigrades from ultraviolet radiation levels, revealing an even more resilient species.
More about these creatures
The phylum of the tardigrades is fascinating. Microscopic creatures are known to survive extreme conditions, such as in the vacuum of space and in temperatures of minus 80ºC, for example. In addition, these species survived the five largest mass extinctions that occurred on Earth.
These animals also tend to be the first beings to colonize harsh environments. For example, when a volcano erupts, lava flows through the ecosystem and it dies. The tardigrades are then the first animals to colonize the environment, feeding on microbes that live there.
The study was published in Biology Letters.