Tardigrade better known as Water Bear, was the first animal I wanted to write about. I can’t explain why I haven’t until now. It looks a little like a caterpillar and has eight legs. They have hard skin and lay eggs like insects but are actually an invertebrate. This creature is tiny, at biggest at 1.5 mm and smallest 0.1 mm long but that doesn’t mean they are weak. Actually it’s the opposite; it’s one of the toughest animals on the planet. Tardigrade have survived in extreme condition like dangerously hot and cold temperatures, high pressure, high levels of radiation, poison, starving, and even the vacuum of space. They have been found in all sorts of habitats from the ocean to the high mountains. Scientist have even frozen them for thirty years and they came back to life.
Most life can’t survive without water for a long period of time, but these can go decades without water. They can do this because of a process called anhydrobiosis, which is a Greek word meaning life without water. A Tardigrade will go through a stage, where they circle up into a ball, withdrawing their head and eight legs inside their body. They will wait until water returns. Scientist thinks they synchronise their molecules, which fills their cells to replace lost water. Cells like DNA that are sensitive to loss of water get trapped in this matrix. It’s theorized that this keeps those molecules in place and stops them from being damaged, breaking part and fusing together.
Of course with these animals being able to survive so many extremes; people have long thought they might be aliens. It has been proven that they’re related to spiders and their closest relatives are nematodes. I’m sure this won’t be the last time, I am writing about these amazing animals.
Source
https://apod.nasa.gov/apod/ap130306.html
http://www.bbc.co.uk/earth/story/20150313-the-toughest-animals-on-earth