Water Bears Are Too Hot To Trot

Tardigrades, colloquially known as water bears or, my favorite, moss piglets; get their name from Tardigrada, Italian for “slow steppers.”

Globally ubiquitous, Tardigrades have been found on all continents and climates and are considered one of the earth's most robust creatures. The secret to this toughness comes from the Tun State; a state of desiccation reached when their preferred environment of a thin film of water, dries out. However, recent research shows that while incredibly tough, Tardigrades do show vulnerability in heat–and climate change is absolutely not helping the problem.

A study recently published in Nature's Scientific Reports shows Tardigrades sensitivity to high temperatures during a variety of states. The report conducted by researchers in the biology dept of the University of Copenhagen focused on Tardigrade Ramazzottius varieornatus, a transient freshwater species sourced from a roof gutter in a Denmark neighborhood.

Testing them in both active and in desiccated states, they found that 50% of active Tardigrades died when exposed to temperatures of 37.1 degrees Celsius for 24 hours. Desiccated Tardigrades fared a bit better, surviving a much higher temperature of 63.1 degrees Celsius before hitting their own surprising 50% mortality rate at 24 hours.

While there are approximately 1300 species of Tardigrade described to date, it goes to show even climate change may sink even the world’s toughest critter. Perhaps the Tardigrades that crash-landed on the moon will have a better chance of surviving the vacuum of space than climate change at home.

Interests peaked? Check out my Tardigrade playlist on YouTube!

Read more on Nature.