Back in the late 18th century, around the time Uranus was discovered and the known boundaries of the solar system were being expanded, science uncovered a fascinating little life-form that still holds people in thrall today: the tardigrade. A micro-animal invisible to the naked eye at less than a millimetre in length, the tardigrade has eyes, legs, a mouth, a brain and bundles of anthropomorphic character. But the really gripping aspect of these tiny animals is their refusal to succumb to injury, of any sort.
Tardigrades have been discovered lolling about in boiling hot springs, could theoretically forage happily in the depths of the deepest ocean trenches, and positively bask in dangerous levels of radiation. They can also maintain their composure at a temperature of one degree Kelvin (just a hair’s breadth off absolute zero).
Their capacity to withstand such extremes of pressure and temperature comes from their flair for cryptobiosis, the ability to bundle themselves up into a little ball with a hard outer shell, legs tucked safely inside the vehicle, and stay like that until conditions prove more amenable. Their metabolism grinds almost to a standstill, rendering them, for all intents and purposes, ex-tardigrades. This can last for decades. Tardigrades thought to be over 100 years old have been resurrected from this desiccated state (known as a ‘tun’) with nothing more than a dash of water.
The name “tardigrade” derives from the German for “slow stepper”, a reference to the ponderous pace of these minute critters. When seen under the microscope, they show up round and cuddly, their eight legs stubby and clawed, a feature that has caused them to be christened “water bears”. The title also comes from their tendency to inhabit moist environments, either on land, in freshwater, or in the sea. Their curious little faces, complete with a pair of anteater-like mouth tubes (stylets), tend to elicit ‘ahhhhhs’ of delight and affection from the viewer.
It may be this absurdly endearing appearance that inspires the levels of excitement and fanaticism often witnessed in recent inductees to the world of the tardigrade. They look friendly, almost knowing, a characteristic surely reinforced by knowledge of their longevity and resilience. There’s something reassuring in that – these guys simply will not die. But the interest sparked by the tardigrade is likely not down to their chubby brand of charm alone; there’s also a great deal of mystique surrounding the creatures.
The bulk of the research done into where tardigrades came from happened around the turn of the 19th century, when three in-depth papers were written and the group were granted their own phylum, ‘tardigrada’. Today, it is estimated there are somewhere in the region of 1,000 different species of tardigrade, thought to be the result of 600 million years of evolution. But the most intriguing recent (2008) development was NASA’s decision to lob a few of these tough guys into space to see how they liked it. They liked it plenty it would seem, returning unscathed after ten days in the vacuum, chipper as ever.
This indifference to the emptiness of our galaxy has prompted one of the more audacious theories about the origins of tardigrades: if they like space so much, maybe they *came* from there, via panspermia (the theory that microscopic life is distributed throughout the universe by planets colliding with meteorites, comets etc.). It’s certainly a far out notion, but one that sits well with these gently tumbling, microscopic bears whose genial, unflustered countenance does seem alien to the hubbub of life on this blue dot.
Start here:
Catch your own pet tardigrade
A pointless undertaking unless you have a microscope (Step 1: Get a microscope), catching a tardigrade is less challenging than one might think. Your best bet is to stalk through the nearest woodland until you come across a likely bit of moss or lichen (after water bear, tardigrades’ second preferred pet name is ‘moss piglet’). Secret this greenery somewhere about your person and hurry home with excitement-sweaty palms. Plonk the moss in a petri dish (if handy), and douse with water. Any dehydrated tardigrades should spring to life (this can take from a few minutes to an hour). You can now train your new pet tardigrade to fetch sticks, roll over, etc.
Mike Shaw
A self-professed tardigrade hunter who dons khaki explorer hats and can be found pottering about in Virginia woods scraping trees with a penknife, Mr. Shaw is the author of the most recently-published (2013) scientific paper on the micro-animals. His website (www.mikeshawtoday.com) provides links to videos and articles on tardigrades, also doubling up as an outlet for microscopes and books by Eckhart Tolle.
Philip Connaughton’s Tardigrade
Previewed in part during the Dublin Dance Festival in May earlier this year, choreographer Philip Connaughton’s dance piece Tardigrade is tipped to feature in its full-length form in this September’s Fringe Festival. A densely-packed piece of performance that glories in its own of decadence, with six-part choral singing, video projections and unabashed nudity.
Words: Rachel Donnelly / Illustration: Fuchsia MacAree
