Science & Technology

The Tardigrade is an Otherwordly Animal That Takes Otherworldly Poops

Some of the world's most amazing animals are the kinds of things you'd be lucky just to encounter once in your life. It takes a boat ride to the open ocean to encounter a blue whale (the largest animal on Earth) and a trip to Africa to see a cheetah (which holds the world's land speed record). Well, chances are there's one little record-breaker that lives right in your backyard. It's called the tardigrade, and on top of surviving extreme temperatures, deadly radiation levels, and the vacuum of space, these extremophiles do one more jaw-dropping thing: they take really big poops.


Tardigrades are microscopic, 0.2-millimeter-long animals sometimes known as "water bears" or "moss piglets" because a) well, just look at them, and b) various species live in either water or semi-aquatic terrestrial environments, like the moss in your backyard. Those little snout-like mouthparts are made for piercing the walls of plant or animal cells, allowing them to suck out the fluids within. While some have been known to prey on other microscopic animals like rotifers or even other tardigrades, many are happy just munching on lichen or algae. That, as recent Harvard Ph.D. graduate Tessa Montague tells LiveScience, is probably what this little guy is pooping in the video below.

As you can see, a body that tiny doesn't waste any room for...well, waste. The large dark mass in the tardigrade's digestive tract seems to take up at least a third of its entire body length, which makes it seem all the more of a relief when it passes through. Afterward, you can see the tardigrade kick all eight of its legs to swim away from it — a feat that wouldn't be quite so tough if it wasn't pressed between two microscope coverslips.

In the video below, you can see another tardigrade relieve itself, this time in full color and without the obstacles. Swim, little guy!

Live Tiny, Die Never

That tardigrade is interesting for another reason: it's the most recently discovered. So far, there are more than 1,200 known species of tardigrade, and little Macrobiotus shonaicus is the newest. Its discovery was published in the journal PLOS One in February 2018 after bioscientist Kazuharu Arakawa found it in his apartment building's parking lot. Yeah. We told you you could find 'em in your own backyard.

It's no wonder that there are so many species of tardigrade, seeing as their biggest claim to fame is the ability to survive any extremes we've thrown at them. We've frozen them to minus 328 degrees Fahrenheit (minus 200 Celsius), heated them beyond 300 degrees Fahrenheit (149 Celsius), subjected them to pressures 6,000 times that of our own atmosphere, and exposed them to doses of radiation thousands of times greater than it would take to kill a human. And they just keep on living.

In fact, they're so tough that scientists believe they would probably survive an asteroid impact, a gamma-ray burst, and even a nearby supernova. That's good news for our search for extraterrestrial life. If tardigrades have similarly tough counterparts on other planets, that means we have a good chance of finding them, even long after more fragile forms of life have died off. The intelligent species might be gone, but the tardigrades will be there, munching on plant life and leaving behind big poops. Such big poops.

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Want to find tardigrades in your own yard? Check out "How To Find Tardigrades and Observe Them Through a Microscope" by Michael W. Shaw for everything you need to get started. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Ashley Hamer June 8, 2018

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