http://www.sciencemag.org/news/2020/10/new-species-water-bear-uses-fluorescent-shield-survive-lethal-uv-radiation

Tardigrades, small aquatic creatures known as water bears, can survive extreme heat, radiation, and even the vacuum of outer space—conditions that would kill most animals. Now, scientists have discovered a new species of tardigrade that can endure ultraviolet (UV) light so lethal, it is regularly used to get rid of hard-to-kill viruses and bacteria.

The discovery was made by chance: Researchers at the Indian Institute of Science scoured their campus for water bears, and then exposed them to extreme conditions. They happened to have a germicidal UV lamp in the lab, so they hit their specimens with it. The dose of 1 kilojoule per square meter, which killed bacteria and roundworms after just 5 minutes, was lethal to Hypsibius exemplaris tardigrades at 15 minutes; most died after 24 hours. But when they hit a strange, reddish brown species with the same dose, all survived. What’s more, when the researchers upped the dose four times, about 60% of the reddish brown bears lived for more than 30 days.