Water bears are micro-arthropods, which are commonly known as the creatures of Reptilia.
Water bears are very small, most of which are less than 1 mm; The whole body is transparent, with a head and four joints, four pairs of feet protruding from the body, and claws, suckers or toes at the ends; There are two protrusions in front of the mouth, one for stabbing food, and the other is an absorption tool. It is named because it can survive in drought and dehydrate itself.
Water bears are distributed all over the world, covering the Arctic, tropics, deep seas and hot springs, and can also live in a vacuum. Habitat in fresh water sediment, wet soil and water film of bryophytes, a few species live in intertidal zone of seawater.
mainly eat foods containing carotenoids. It has the habit of hidden life and is a state similar to suspended animation; The vitality is extremely tenacious, and there are no natural enemies. Whether it is frozen, dry, hungry or lacking oxygen, it can survive. Water bears are hermaphroditic, oviparous and develop directly.
Extreme temperature:
It can survive for 2 minutes at -272℃ and 151℃, several days at -2℃ and at least 3 years at -2℃. The dose of ionizing radiation it can withstand is hundreds of times that of human lethal dose. The pressure that can withstand is about 6 times that of the deepest trench at present, and people may be crushed to deformation under the same pressure.
Water bears can tolerate the temperature range of -2-149℃. They do this by draining water from their bodies, retracting their fat limbs and curling into dehydrated spheres.
after the threat is removed, they are recharged and return to normal, as if they had not suffered any harm. According to a research result released in 217, the probability of successful recovery of water bears that can continuously produce a special protein is higher than that of their companions that don't always produce this kind of protein. In other words, this special protein may be the key for water bears to endure extreme heat and cold.
above content reference: Baidu Encyclopedia-Water Bear