Friday, July 22, 2011

Interesting Animals: Tardigrade

One of the Phylum Tardigrada, specifically Hypsibius dujardini

This is another case of being more than just one species. Instead, tardigrades (meaning "slow walker") are an entire phylum: Tardigrada. Also known as the water bear, these microscopic invertebrates are the most resilient animals to be found on this planet. By going into a resting stage called cryptobiosis, they can withstand extremes that would easily kill other animals, including us humans. Here's some things that won't kill a water bear:
  • temperatures up to 150 degrees Celsius
  • absurd amounts of radiation (570,00 roentgens killed only half of them)
  • temperatures up to minus 200 Celsius
  • extended periods of dessication (being dried out)
  • the vacuum of space
Crazy, right? Tardigrades are the only animal to ever survive the process of being sent through a scanning electron microscope. This is a process that involves being placed in a vacuum and then bombarded with electrons for over an hour. Amazingly, the animal pictured above in just such a SEM micrograph probably survived the process. They are also a numerous animal, to be found fairly easily in places like patches of moss.

The genome of these tiny creatures is currently being sequenced.

Image is from Wikimedia Commons under a creative commons license


  1. Daw, so cute, I want to tickle it's little belly.

  2. I know, right? I absolutely love tardigrades.

    I took a class where we had to collect invertebrates. Spent about three weeks sifting through moss scrapings for these guys. No luck. Then, someone else found one at random. Isn't that always how it is?