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The 'world’s toughest animal' is tiny – like a comma
"They walk like small, cute bears," says researcher.
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"They can survive things that would be completely extreme for other animals," says researcher Torbjørn Ekrem.
Think mass extinctions, starvation, boiling, drought, and radiation.
Older than the dinosaurs
These tough little creatures, colloquially known as water bears, only grow up to two millimetres long.
"They're like a tiny comma in a book," says the researcher. "And they walk like small, cute bears."
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That's where their nickname comes from – but they also share another bear-like trait.
"They can hibernate. And that's one of the reasons the tardigrade survives virtually everything," says Ekrem.
Tardigrades have lived on our planet for at least 570 million years, long before dinosaurs ever appeared.
"We know this because we've found tiny fossils of them," says Ekrem.
And they will most likely continue to exist for a very long time yet.
The tardigrade 'switches off'
How can a tardigrade survive so many harsh conditions?
"Researchers have studied this, and we see that they create a kind of protective shell around themselves when they hibernate," says Ekrem.
This is triggered when it becomes too hot, cold, dry, or difficult to live.
"It enters a state called cryptobiosis. There are so few signs of life that it's almost dead," says Ekrem. "Its metabolism drops to just 0.01 per cent of normal, which is absolutely extreme."
Can we learn anything from tardigrades?
"What's the most fun research on tardigrades?"
Ekrem says their incredible survival abilities open the door to all kinds of exciting research.
"One of the most fun things must be that they're sent into space, completely without protection, and return alive," he says.
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"Can we learn anything from them?"
"They don't have much brain capacity. But we can learn not to give up. If the tardigrade has somewhat boring living conditions, it waits patiently for things to get better. We can learn from that," he says.
Researchers have also tried to copy the protective hibernation shell.
"They're trying to create the same strong material," he says.
Want to go tardigrade hunting?
"There are plenty of tardigrades out there," says Ekrem.
He has searched for them himself, and they can be found almost everywhere in nature.
They live in warm and cold regions, in the deepest oceans and on the highest mountain peaks. But they are so small that it's impossible to spot them without help. Ekrem shares some tips.
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What you need:
A bucket, a plastic bottle with the top cut off, water, a magnifying glass, a transparent bowl, a black surface, and good lighting.
First, you need to pick some moss in the forest.
"There's a good chance you'll bring tardigrades along with it. There can be as many as 900 individuals per gram of moss," says Ekrem.
Place the moss in a bucket with one litre of water for 30 minutes, then mix it with your hands for about one minute.
Remove the moss and pour the water and sediment into a container. Ekrem uses measuring cylinders in the lab, but a cut-off water bottle works fine. Wait about half an hour.
"That way, both the sediment and the tardigrades sink to the bottom. They are heavier than water," says Ekrem.
Carefully pour away the water, but leave the sediments in the bottle. Transfer some of the sediment into a transparent bowl, add clean water, and place the bowl on a black surface.
With a magnifying glass or microscope with at least 20x magnification, there's a good chance you'll get to see one of the world's toughest creatures in the flesh.
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Translated by Alette Bjordal Gjellesvik
Read the Norwegian version of this article on ung.forskning.no
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