The incredible water bear

Strangely enough, water bears are at the same time among the most unknown and the most fascinating creatures on earth. They have successfully escaped man's exploitation of nature and still can be found almost everywhere on earth. Scientists have reported their existence in hot springs, on top of the Himalayas, under 5 m layers of solid ice and in ocean sediments.



Many species can be found in a milder environment like lakes, ponds and meadows, others prefer stone walls and roofs. But their most typical homes are moss cushions. I spent some time in nearby mushroom-smelling forests, scrutinizing mosses on rotten trunks in an avid search for water bears until I came to the simple conclusion that they can be found virtually everywhere - normally just one or two steps out of your front-door.

How is it possible that an animal can be found almost everywhere and at the same time is unknown to almost everybody? Just try and ask your neighbour whether he or she knows or believes in an animal which:

— lives nearby, including cities
— moves smoothly like a bear, has legs, claws, eyes, skin and muscles
— has the colour and surface texture of one of those sweet bear gums loved by children
— doesn't need to carry along a knife and fork as it has two in-built knives
— can revert to an "instant coffee"-dry state which resists storage in liquid nitrogen, contact with mineral acids, organic solvents, radioactive radiation and boiling water. After this kind of brute "scientific" scrutiny the miraculous creature is still able to return to normal life—it needs only a small droplet of water!

Strangely enough, even the big encyclopaedias spend only a few lines and seldom an illustration on the subject of the water bears (the scientific name is Tardigrada, i.e. slow-walking animals). Alfred Kaestner's comprehensive biology textbook1 admits that a whole phylum has been reserved for those strange water bears, but at the same time suggests that the student might skip the chapter because of its minor importance. But from the very beginning microscopists were so fascinated by the water bears that they were not able to conceal their astonishment behind sober scientific terms. It is not easy to describe by words a microscopic creature which apparently stretches our understanding of the microscopic world and its natural limits:

J.A.E. Goeze, pastor in Quedlinburg, Germany was the first person who published a paper on water bears. In 1773 he notes in his book; "Strange is this animal ... because it resembles a bear in miniature"2.


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