Tardigrades Case

Tardigrades more commonly known as "water bears" are the most desiccation and radiation tolerant animals known, this being so they are also the only known and recorded animal to ever survive a space vacuum and solar radiation combined. Bacteria and Lichens have also been known to survive these harsh conditions, but Tardigrades are the only known animal. Tardigrades also have the ability known as anhydrobiosis, which is a certain type of cryptobiosis. Having this ability gives you the advantage to suspend life, and there is no metabolism rate detected. Cryptobiosis is induced by extreme temperatures, and also hydration or salinity. Tardigrades are equipped with the ability to survive dehydration, up to where the body only contains 2% water. To give an example of how extreme that is, humans will die if their % water composition drops 12% which is to about 64%. These water bears have also been known to survive temperatures nearing absolute zero and temperatures all the way up to 100 degrees Celsius. When the tardigrade is in the anhydrobiotic stage, it has been known to survive up to several years in that state. While in that state the aging process is slowed dramatically or even stopped. Some recent studies have shown that tardigrade eggs can survive the extreme conditions of solar radiation and space vacuum better than adult tardigrades.

Both experiments of these papers had to do with the experimental testing of tardigrades and what severe conditions their eggs and themselves could survive. In one paper, the cultures they had the water bears grow on were in a 20 degree Celsius environmental chamber that experienced a period of light and dark for 12 hours each. This went on for 5 days as the different stages of the tardigrades grew. They had 5 different stages of the tardigrades; stage 1 was the blastula stage, stage 2 was 24 hours after the blastula stage, stage 3 was 72 hours after the blastula stage, stage 4 was 96 hours after the blastula stage, and stage 5 was 120 hours after the blastula stage. A few hours after stage 5 was complete hatching occurred. Batches of the embryos representing all stages of development were used to study their desiccation tolerance. One clutch per trial which all had a different number of embryos was used for each humidity treatment. There were 8 different humidity levels that were used to test the survivability of the tardigrade stages. The anhydrobiotic embryos were contained in the humidity conditions for 7 days. After the 7th day all of the embryos were hydrated with Volvic water that was room temperature. During the next few days the scientists observed the tardigrade embryos as they hatched.

In the other paper the scientists tested the tardigrades and by exposing them to a space vacuum and two different UV radiation spectral ranges. They also tested to see how well they reproduced post exposure to drastic environments. After exposing them to these conditions, they observed to see if