As an Earth Touch crew leaves sunny South Africa behind to do some serious chilling out in Antarctica (check out their journey to the bottom of the world!), we’ve been thinking about some of the extreme adaptations necessary for survival when temperatures plummet below zero. From powerful antifreeze to crazy cryogenics and dehydration verging on death, these animals (and one amazing bacterium) have evolved some impressive tactics for sub-zero survival. 


Hatchlings of the painted turtle (found in freshwater habitats in the US and Canada) have more than one trick up the sleeve for overcoming the big winter chill (and some of them are not yet completely understood by scientists). The hardy youngsters are the supercooling superstars of the vertebrate world (they can keep their body fluids liquid in temps well below zero) and they can also endure partial freezing, surviving even substantial ice formation within their tissues. Their response to the cold varies depending on the environmental conditions surrounding their nest. Click here to see a few hatchlings “wake up” from an icy sleep. 


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Image credit: Vlad Proklov, Flickr

In the depths of the Alaskan winter, the Upis beetle endures temperatures as low as -100°F. When the mercury plunges to about -19°F, the hardy insect freezes, but it’s able to survive in this frozen state thanks to a special anti-freeze-style sugar called xylomannan. The substance doesn’t actually prevent freezing but instead slows ice formation and ensures the freezing process doesn’t get rowdy enough to damage the beetle’s cells. 


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Image credit: iwona_kellie, Flickr

Found in many cold regions, including the Arctic, banded woolly bears (the larvae of the Isabella tiger moth) are just like any other small, hairy caterpillars that spend most of their time eating their way to pupation – except they’re so much more awesome! Out in the polar extremes of the Arctic, these amazing little creatures actually spend about 90% of their lives in a frozen state (protected from the damaging effects of ice by cryoprotectant substances in their tissues). Unlike caterpillars in other parts of the world, woolly bears in the Arctic don’t pupate after a season’s gorging. Instead, they can survive for years (some reports say up to 13!) alternating between freezing, thawing and feeding.


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Image credit: Travis S., Flickr

When it comes to hunkering down for the winter, the wood frog Rana sylvatica doesn’t take any half measures … it literally turns itself into a solid little frogsicle. The heart stops, all muscle and breathing movements cease and up to 70% of the body freezes (even the brain and the lens of the eye). And yet come spring, the frogs thaw out and hop right back into life. This amazing case of cryogenics is possible thanks to several special adaptations, including the special 'antifreeze' role played by glucose in the frog’s body. Check out the frog in all of its frozen glory here.


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Image credit: Don Loarie, Flickr

It's not known as nature's greatest survivor for nothing! The tardigrade (or water bear ... or, more endearingly, the moss piglet) might be miniscule (most are no bigger than 1mm in length), but these creatures are positively revelling in their own indestructibility. To start with, some tardigrades can survive being frozen to -359°F (-273°C). But why stop there? They can also be boiled, nuked, exposed to extreme pressures and launched into the vacuum of space (they hitched a ride on the Endeavour in 2011). As we said: virtually indestructible. So what’s their secret? While there have been suggestions of the extraterrestrial kind, scientists believe the tiny invertebrates survive by entering a death-like dehydrated state known as cryptobiosis. 


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Herminiimonas glaciei bacteria

We saved this one for last because the life form in question hails from a different (bacterial) domain ... but we thought surviving 120,000 years buried three kilometres deep in the Greenland ice sheet was a feat impressive enough to make the grade anyway. The amazing 'resurrection' of Herminiimonas glaciei occured when scientists retrieved ancient ice from the base of a Greenland glacier and then revived the microbes found within by slowly warming them up. Scientists believe the bug's extensive tail-like flagella and tiny size (it consists of rods just 0.9 micrometres long and 0.4 micrometres in diameter) allowed it to manoeuvre within tiny veins of ice as it searched for edible debris frozen within. And the craziest thing? Herminiimonas glaciei is not even the most ancient superbug brought back to life. The winning contender was extracted from the oldest ice on the planet and was about eight million years old.