Water bears, revived after 30 years frozen, are grand

17 Feb 2016

This is what a water bear looks like, somewhat

There is only one documented species of animal to have survived exposure to the immense pressure of space, as well producing offspring 30 years after being frozen in state. Step forward the tardigrade.

A weird, troubling-looking nightmare, tardigrades – known as ‘water bears’ – are only around one millimetre in length, but what they lack in size they more than make up for in durability.

So much so, that researchers in Japan have recently discovered some that were frozen 30 years ago, reheated and rehydrated, before getting back to the day job of eating and reproducing.

Future Human

The tiny creatures’ 30-year revival – after being frozen in an Antarctic moss sample – is a new record, and the resumption of reproductive abilities is a first.

Tokyo scientists will now try to learn more about the species’ “cryptobiosis abilities”, after two individuals and one egg survived, to varying degrees.

Varied success

While one died after a while, the other water bear and the juvenile that hatched from the revived egg went on to continuous reproduction successfully.

It was a slow process, recovering from three decades in the ice, with around two weeks needed for the fully prospering tardigrade to get back up to speed. Interestingly, its first egg that it hatched took 19 days to hatch, double that of subsequent eggs.

So, basically, it eased itself back into the world at its own pace.

“Our team now aims at unravelling the mechanisms underlying the long-term survival of cryptobiotic organisms by studying damage to tardigrades’ DNA and their ability to repair it,” said Megumu Tsujimto, the lead author of the paper published in Cryobiology.

What’s all the fuss?

But we shouldn’t really be too surprised, for tardigrades are immensely durable.

In the past decade, water bears have been tested in the most extreme environments. Some were doused in radiation, others put into highly-pressurised scenarios and some even heated up to incredible temperatures.

They survived it all.

But the ultimate test, though, came back in 2007 when European researchers got a bit otherworldly and sent some water bears up to space. They were dehydrated and then put up into the vacuum and solar radiation of outer space for 10 full days.

They survived it all.

So the next time someone says nothing can survive in space, nothing can survive being completely frozen, nothing can survive being heated up to 300ºF, correct them immediately. For water bears are nature’s truly invincible animals.

Water bear image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic