h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Tardigrades are my new favorite creatures. Does anybody know where I can find these little guys? I know they're really teeny, but I should be able to see them without a microscope, right? Do they live in every part of the world? I live in the mossy Pacific Northwest of the U.S. - should I be able to find them in my back yard?

I had to google it, because I didn't know what it is.

'They actually prefer regular old dirt and sand and moss all over the world.'

Quoted from this article, with a very cute photo at the very top:
http://www.wired.com/2014/03/absurd-creature-week-water-bear/

Also, from the same article:

'Ironically enough, these incredibly hardy creatures are very difficult to grow in the lab'

How silly of me, I should have searched h2g2 first:

http://h2g2.com/edited_entry/A827282

Puddles, muck, sand...you name it, they're there!

Thank you! I just now found the responses here! I had no idea anyone had actually answered my question...

And I didn't know that h2g2 had already talked about this. Great article. This part was new information for me: "Water bears feed on the fluids in plant and animal cells. Sometimes they eat entire other organisms, like rotifers and even, on occasion, other water bears. They can pierce the walls or membranes of cells and they possess a tube to eat the internal contents of their prey."

I had no idea the little fellows were cannibals!!!

Yes Karen, you should be able to find several tardigrades in your back yard. Though they are sometimes cannibals their favourite food is fajitas (though not *too* spicy). Sit out back with a fajita or, if you're pushed, a quesadilla, and whistle gently, and pretty soon you'll have two or even three water bears of your very own to cuddle and pet and show off to your friends.

I'm thinking a moss-covered fajita would probably be best, right?

I managed to find a "hunt your own tardigrades" guide right here:

http://tardigrade.us/how-to-articles/how-to-find-tardigrades/

It's nowhere near as much fun as growing moss on fajitas, but it may well have slightly better results.

hygienicdispenser - Thank you! That is exactly what I needed - step-by-step directions. I've got the lichen and the moss - now all I need is the microscope...

What a waste of a fajita...

Tardigrades are often classified with the arachnids since after their second moult they have eight legs.

On the other hand they have six legs after the first moult and when they first hatch from the egg, four.*

I personally think that they're something more primal.

To me, they look like little caterpillars, but they never metamorphose into a hard shelled arthropod.




They've been reported aboard the International Space Station and other spacecraft.




*There may be a clue here to the 2legs mystery.

Well, you do need at least a light microscope to see them. I accidentally discovered one when I picked up some moss to look at under my microscope. I was taking a class in the general types of organisms on Earth and I got a microscope so I would have more time to look at different microscopic things than we were afforded at the laboratory.

Anyway, I picked up this bit of moss and put it under the microscope only to see the Tardigrade busily eating other microscopic organisms and a few moss cells. I probably watched it for an hour or so before I had to go to class again. I put the slide in the refrigerator because I wanted to look at it again later.

When I got home, I took the slide out and found that the fridge only slowed the Tardigrade down. My fridge is really cold (since I like a good cold beer) so the Tardigrade had slowed down so much that it's heart-like organ wasn't pumping as far as I could tell. As the light from the microscope warmed it up, its little heart organ began to pump faster. It's weird because you can kind of see right through them so you can see their internal organs working, particularly the heart-like organ. I say heart-like because its heart is actually more like a tube that propels all its body fluids around. This includes all kinds of other particles that it must have eaten. They are weird and definitely worth putting under a microscope. The only other organism that I was equally amazed by was the amoeba that I watched trying to escape the hot microscope light by sticking part of its cell membrane out and getting the rest of its cellular contents to flow that way. Seeing that was also a trip. Of course, pretty much anything you put under a microscope is cool, even table salt!

They've recently discovered that tardigrades also live in Antarctica.

I'm unsurprised.

Mitey Earth!

One of the most common types of tardigrades is the common housemite, commonly found wherever there are accumulations of household dust.

I happen to know about them because I'm allergic to that variety and prone to double over gasping, choking, wheezing, retching and vomiting if I'm exposed to them.

Another type lives in the follicles of human eyelashes and helps to keep them free of waxy or oily buildups.

Yoginamy - wow! Thank you for your post!Fantastic description of what you saw under the microscope! (I liked you description of the amoeba's attempt to escape the hot microscope light, too - fascinating stuff!)

Mites are a type of arthropod, related to spiders, crabs and insects. Tardigrades are not mites. They're a different thing entirely, not related to arthropods or any other type of creature.

Mites?! Tardigrades are mites?!! Well, that is kind of a disappointment...

No, I just said they're not mites.

Those things creep me out!