Meet The Tardigrade — The Universe’s Most Resilient Animal

Published March 27, 2018

The tardigrade has baffled scientists for years, for its ability to survive everything it's been exposed to so far – even space.


Wikimedia Commons Tardigrade under a microscope.

No creature on earth, or perhaps in the universe, has been through as much as the tardigrade and lived to tell the tale.

Measuring just over one millimeter, the tardigrade is by no means a sizeable animal. In fact, you’ve probably never seen one. But don’t let its minuscule stature fool you. It may be teeny, but it’s probably tougher than you are.

From the bottom of the ocean to the canopies of the rainforest, and from the tundras of Antarctica to the surface of a volcano, the tardigrade has been there and done that. And, most surprisingly, lived through it to baffle scientists worldwide. Tardigrades have even been sent into the vacuum of space, where no man has gone before, and come back perfectly fine.

They’ve also been around forever. Though they were first discovered in 1773 by German zoologist Johann August Ephraim Goeze, fossils of tardigrades have been found and dated back 530 million years ago.

Goeze named his discovery kleiner Wasserbär, meaning “little water bear,” a moniker which has stuck around. The nickname came from the tardigrade’s gait, which resembles that of a bear. The animals scientific name, tardigradum, means “slow walker, and when watching videos of the little creatures, it’s almost impossible not to see the similarities between a slow walking bear.

While their gait may be similar to a bear’s, the similarities end there. Tardigrades are short and plump, with eight short, stubby legs. Each joint-less leg ends in four to eight claws, which help the tardigrade cling to surfaces.

They have a small, flat face, with an extendable mouth that bobs in and out as it moves through its surroundings. Some species of tardigrade even have little eyes, perceptible in a microscope, that gives them even more character. Despite their strange appearance, one can’t help but think of a tardigrade as bizarrely adorable.

The tardigrade has been a favorite of scientists and students for years due to its seemingly indestructible body. In addition to being able to survive water, fire, and space, the little animal has been known to survive radiation, dehydration, starvation, air deprivation, and extreme pressures and temperatures (both high and low).

When they’re dried out, the tardigrade goes into a conservation mode, rolling in on itself and turning into what scientists call a “tun.” In this state, it produces glycerol (also known as antifreeze) which helps it survive. As a tun, tardigrades also reduce their own metabolism by about 99.99 percent so that food becomes unnecessary. In this state, they could theoretically survive for 100 years.

For centuries, the tardigrade has baffled scientists and continues to do so. In 2016, scientists successfully revived a tardigrade that had been frozen for over three decades, opening up new theories on the animal’s survival in relation to freezing temperatures.

So, what does an indestructible animal eat when it’s not in hibernation mode? For the most part, plants. The tardigrade survives on mostly algae, consuming plant substances for sustenance. That is, of course, when it’s eating.

So there you have it, the most amazing creature on earth. Indestructible enough for open space travel, and hearty enough to survive decades in hibernation, the tardigrade might just outlive us all.

Next, check out this baffling bald South American bear. Then, check out this mystery sea creature that washed up on shore in Indonesia.

Katie Serena
Katie Serena is a New York City-based writer and a staff writer at All That's Interesting.
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