Bears in your Backyard

Adventures in Astrobiology
SETI Institute ASSET Program
Cathrine Prenot Fox

Quick quiz: what has eight legs, multiple knife-like appendages, can be boiled, frozen and exposed to pressure that would make us pop, and yet lives peacefully in our backyard on plants, algae and lichen?  Any guesses?  No?

I'd like to introduce you to members of the animal phyla Tardigrada.  There are about 1,000 different species of this group of microscopic animals commonly known as waterbears or moss piglets.  They were first "described" in 1773 by the German zoologist Johann August Ephraim Goeze.  After spending years cataloging aquatic insects and worms you can imagine his sense of wonder when he came across these:

Colorized SEM image of a Tardigrate from here.

What is particularly interesting to me about Tardigrates is their ability to survive extreme conditions.  As I alluded, they have been found on all of the continents, in pack ice, the Himalayas, brine water, fresh water, and in moss or lichen growing in your backyard.  This adaptability, and their tolerance for extreme conditions that most life cannot exist in has put them in a group of exciting organisms dubbed "extremophiles."

 Let me help you further make their acquaintance with an excellent video from Science Friday that so captivated one of my advanced biology students, Whitney, that she wrote a song about them:

Waterbears!  Waterbears!
My favorite phyla except oursssss.
Live in space, Himalaya, 
radiation and boiling cannot harm.


Waterbears!  Waterbears!
in Antarctica they surviveeeee.
Legs of eight, really great!
Live in moss and maybe Mars.


These are only the first two verses out of five, and since we never properly recorded it let me expose you to another song from Mal Webb.


Life as we know it is enriched by an understanding of extremophiles, as it may change the parameters we use when looking outward into our solar system and the universe for indicators of life.  Why don't you read a little more about them in Bears in your Backyard (cartoon citations 1, 2, 3, and 4)?

Adventures in Astrobiology.  Cathrine Prenot Fox, 2012.  

Grand prismatic spring in Yellowstone National Park from here.

You may not be able to sample deep sea vents for six foot long tube worms, or travel to Yellowstone to see the bacteria thriving in Grand Prismatic spring, but you can easily collect and view a variety of tardigrades by following these excellent instructions.  Perhaps you may even find a relative of one of the ones that was sent to Mars's moon, Phobos in 2011.

Best of luck!
Until our next adventure,
Cat


All right, I just can't help myself: two more links.  A great cartoon from Small Science Zines:

smallsciencezines.blogspot.com

...and a final word from the beloved waterbear:

From here.