Hidden BRITAIN
REVEALS A FASCINATING WORLD OF WILDLIFE THAT WE OFTEN OVERLOOK.
They’re probably among the most unbreakable creatures on Earth, able to survive dehydration, microwaving and temperatures as hot as 150ºC or as low as –273ºC. They can also cope with being exposed to the ionising radiation of outer-space. Not tough enough? On top of all of these credentials, they can exist in suspended animation for over three decades. It is also claimed that these animals have the physiological capabilities to be the last beast standing in the event of a nuclear holocaust.
Tardigrades, which translates as ‘slow walkers’, are found from the deepest ocean sediments to the top of Mount Everest. But, luckily for you, they live in less exotic and more user-friendly locations too. That clump of moss on your garden wall or in your blocked gutter, for instance.
Tardigrades are also known as ‘water bears’ and ‘moss piglets’. Neither is a name that you would associate with such tough nuts, though these monikers go some way to describing the animals’ bumbling gait and chubby, turgid appearance. They’re clearly not mammals, however. Indeed, they are so weird and unlike any other life-forms that the 1,100 or so species have earned themselves a phylum all of their own: Tardigrada. To put this in context: humans, real bears and actual pigs belong to the phylum Chordata, which includes all animals with backbones. In short, there is nothing quite like tardigrades – they’re unique. If you’re wondering why you’ve never bumped into one, it’s because they require a bit of looking for. Even a large tardigrade is just 1mm in length, hardly colossal, so is easily missed. But tardigrades are as fascinating as they are small, and worth the extra effort to try to find – they’re probably among the few microscopic creatures that could be described as cute.
Going on a bear hunt
That quilted, segmented, transparent body is equipped with four pairs of fleshy legs, each of which ends in a set of retractable claws (4–8 depending on species). These are used to swim or grapple their way through water and over damp surfaces. Their ‘face’ sometimes has a basic eye-spot oon each side, but centrally p positioned is the feeding tube thhrough which the animals hhoover up bacteria and algae.
Intrigued? Want to meet one? WWell, going on a bear hunt is reeally easy but you do need some foform of magnification. While soome large specimens can just aabout be seen with a hand lens, a microscope that can achieve aaround x15–x30 magnification is bbest, and x100 is even better.
All you need to do is scrape up a small quantity of soggy autumn leeaves, a clump of moss or a frfragment of lichen and then soak itt. This is necessary to increase yyour chances of finding one, siince any in their tun stage will hhave had time to rehydrate and bbecome mobile. Now wring the mmaterial out, squeezing between yyour fingers, and collect the liiquid. Next place a few drops at a time in a small, clear-sided pot, suuch as a petri dish.
Search through this liquid uusing a bright light or lamp shhone from the sides. When yyou finally clamp your eyes on a dumpy creature complete wwith eight curious grasping liimbs, you know you’ve found yyour tardigrade. It’s an animal everyone should meet at least oonce in their lives.