This organism has a short body, divided into four segments and covered with a protective cuticle, from which eight legs come out, ending in nails. Its popular name "water bear" comes from the similarity it has with the bear, both in its appearance and in its gait.
The tardigrades endure the most extreme conditions. "Some specimens were kept for eight days under vacuum, then three days in helium at room temperature and finally several hours at -272 ° C (-458 ° F). In spite of everything, when they were placed again under normal thermal conditions, they revived, "says the Encyclopædia Britannica. In addition, they hold an X-ray dose hundreds of times stronger than that required to kill a man. And, at least in theory, they can survive in outer space for a certain time.
What is your secret?
The secret lies in their ability to enter a state of latency in which their metabolism drops to less than a hundredth of the normal, a practically undetectable level. In order to reach this state, the legs are retracted inside the body, the lost water is replaced by a special sugar and they are rolled up into a wax-covered ball called a barrel. When they recover normal humidity conditions, they take between a few minutes and a few hours to reactivate. In the laboratory they have revived tardigrades that had more than a hundred years in a state of suspended animation.
There are hundreds of species, which are reproduced through the eggs that the females place: from one to thirty in each laying. In just a handful of sand or wet earth there can be tens of thousands of these tiny animals. A very suitable place to locate them is in the mosses of the roofs, but it is also found in almost any humid environment, such as ice, streams, thermal springs, lakes and seas, or even in domestic gardens.
The next time you look at a wet spot, remember that there is probably "the water bear" a super resistant creature, who speaks very well of who designed it.