Tardigrades live - outside (part III, interpretation)

Well, meanwhile there are many web pages boasting with an assumed (but wrong) tardigrade immortality claim. As a consequence our website ranking has declined from a former no. 1 or no. 2 position to a no. 10 and worse. The funny thing is that we do not care very much about this, though we probably would have cared a decade ago ...

In any case there can be no doubt that the multimedia competition has increased. Some decades ago a dolphine portrait like the following could have sufficed to receive some public appraisal or even a modest fee:

fig. 1: Photograph taken in Croatia during a tourists' dolphin tour near Rovinj, in the Northern Adriatic Sea.

Well, at first we were really proud of this photograph: taken with an old 300 mm objective in the evening (low-light ...), and definitely at the right moment. Notably without autofocus. But, soberly speaking this photograph isn't more than merely a personal souvenir. There are thousands of similar and better photographs of dolphins spread all over the internet. Besides, it was a highly emotional encounter, supported by some sweet Croatian wine. But why publish it?

As a consequence it makes sense to concentrate on something really unique, like the photographs shown in the previous issue of our magazine:

Fig. 2: View through a 30 US $ stereo microscope (a low magnification dissecting microscope) onto a cement wall in wet state.

Fig. 3: A two individuums' expedition through difficult terrain? Detail of fig. 2. Please note that this is a highly over-magnified view, with the photograph taken just by holding a CCD camera above one of the eye-pieces. The actual visual impression was much better. The two tardigrades were crawling through the water layer of the wet cement surface into the same direction. It was even possible to see the tiny claws in action! This is not 5k res, not 4k res, even worse than webcam - but nevertheless fascinating.

The two photographs shown above are definitely of very low technical quality. Nevertheless they are well able to provide thrilling insight into tardigrade life: possibly you have already seen one of those videos where an orca whale is approaching a beach in order to prey on sea lions? The orca scenario looks like an autobus emerging out of the water, still being surrounded by a small layer of water.

In case of the terrestrial tardigrades the scenario is miniaturized but looking similar. A wet cement or stone wall doesn't provide big quantities of water but it is sufficient to form a thin water layer around the moving tardigrades. Just remember that their oxygen intake depends on water and diffusion. Without this thin layer of water they would die within seconds. So some courage is needed to quit a safe moss cushion and to move through a tiny water coat to another moss cushion. Or do you think that this is just a simple use of miniature water physics?

We do not know what those tiny pioneers are actually able to see and how big the risk is. In any case it becomes clear that we have a pair of female tardigrades in an expedition situation. And we do not know the motive of those two ladies to leave one safe moss cushion in order to reach out for a second, distant one.

This is quite fascinating and we would like to point out to our readers that investigations of this kind are actually much more rewarding than the typical scholarly mass murder experiments with UV, vacuum, acid attack, freezing etc. in the desperate school or science environment!

© Text, images and video clips by  Martin Mach  (webmaster@baertierchen.de).
The Water Bear web base is a licensed and revised version of the German language monthly magazine  Bärtierchen-Journal . Style and grammar amendments by native speakers are warmly welcomed.

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