Tardigrades or it's commonly known as water bears or moss- piglets they are water dwelling segment micro animals with eight legs Tardigrade are notable for being the most complex of the existed polyextremophiles .

An extremophile is an organism that can survive under extreme conditions that could destroy most of
life on Earth and the following list is will explain it's large ability to survive

1. Temperature : Tardigrades can endurance 151celisuis degrees ( 424 k or 304 F ) for a few minutes or being chilled for days at -200 celisuis degrees (73 k or -328 F ) or some can survive at -273 celisuis degrees ( 0 k or -458 F ) for few minutes

2. outer space : Tardigrades are the only known organism to survive in space

3. Pressure : Tardigrade can whithstand vacuum pressure of space and more than atmospheric pressure by 1200 times and the can live for at least 10 days in space vacuum and solar radiation combined

4. radiation : Tardigrades can withstand radiation with range between 1 to 6000 Gy only animals could withstand 5 to 10 Gy ( could be fatal to humans )

5. environmental toxins : there is evidence that tardigrades can undergo chemobiosis , a cryptobiotic response to high levels of environmental toxins . However as of 2001 these laboratory results has yet to be verfied
Ecology and life history
Most of tardigrades are plant eaters or bacteria eaters but some of them are predatory
( eg.milnesium tardigradum )