Tardigrades are microscopic organisms with eight limbs that exhibit odd, alien-like behavior. They are remarkably plentiful, according to William Miller, a senior tardigrade researcher at Baker University. Hundreds of species can be found "all across the world, from the highest mountain to the deepest sea," he says. "Many tardigrade species reside in water, although they can be found practically anywhere there is moss or lichen on land."
A tardigrade looks like a cross between a hookah-smoking caterpillar from Disney's Alice in Wonderland and a vacuum cleaner bag, and it's easy to see why. However, as scientists have discovered over the years, their unusual appearance is merely the beginning. Here are a few of our favorite facts about one of the most fascinating animals on the planet.
A tardigrade looks like a cross between a hookah-smoking caterpillar from Disney's Alice in Wonderland and a vacuum cleaner bag, and it's easy to see why. However, as scientists have discovered over the years, their unusual appearance is merely the beginning. Here are a few of our favorite facts about one of the most fascinating animals on the planet.
Lifestyle of Tardigrades
Tardigrades are also known as water bears or moss piglets, but the name 'tardigrade' literally means' slow-moving.' It was originally a tortoise adjective, but it has been the name of these microscopic animals since 1800. Tardigrades are little, measuring only around 0.5mm in length, but they can be found in a variety of settings all over the world.
The tardigrades were in "tun" form, a dormant stage in which they shrivel up into a ball, expel most of the water in their bodies, and slow their metabolism via cryptobiosis until they enter a more suitable environment for life. They can last for decades in this state. They're also pretty tough, able to withstand even the most extreme conditions, like subzero temperatures—and, you know, lunar crash landings.
The tardigrades were in "tun" form, a dormant stage in which they shrivel up into a ball, expel most of the water in their bodies, and slow their metabolism via cryptobiosis until they enter a more suitable environment for life. They can last for decades in this state. They're also pretty tough, able to withstand even the most extreme conditions, like subzero temperatures—and, you know, lunar crash landings.
What Do Tardigrades Eat?
Basically, Bacteria, plants, and even other tardigrades are eaten by tardigrades. They penetrate their prey's cells and suck out the contents for nutrition. Delicious! A tun, like a seed or spore, can be carried by the wind. It can asexually reproduce and form a new colony if it landed in a habitable habitat. Dehydrated tardigrades were launched into space in 2007 and exposed to the vacuum and radiation of space for ten days.
Surviving in the Vacuum of Space
Over two-thirds of them were successfully resurrected upon their return to Earth. Many died soon after, yet they were still able to reproduce before they died. Of course, this does not imply that tardigrades are extraterrestrials. Tardigrades are one of the few species to have survived all five of the world's major extinction catastrophes.
The Israeli lunar lander Beresheet crashed onto the Moon's surface in April 2019, therefore ending its mission. However, among the cargo was a colony of tardigrades, which scientists estimate are quite likely to have survived the hit (along with classic literature, human blood samples, and the contents of Wikipedia).
The Hardiest Critters on Earth - And Beyond
Tardigrades can withstand temperatures so harsh that they would kill other organisms. Some species can endure temperatures as low as -272.15°C, while others may withstand temperatures as high as 150°C for a short duration. By encoding tardigrade genes for generating TDPs into yeast and bacteria, they can be protected from dehydration. This technology could be used to create drought-resistant crops or medication that doesn't need to be refrigerated.
Tardigrades lack multiple Hox genes as well as a big portion of the body axis in the middle. This refers to the entire thorax as well as the abdomen in insects. Except for the last pair of legs, the entire body is built up of segments that are comparable to the head area in arthropods.