Thai tardies (II)

We go back to the last photograph from the previous issue - perhaps you will remember that we had found an empty tardigrade cuticula, in a maritime sand sample from Thailand.

Empty cuticula of a maritime tardigrade, left behind after moulting.

But, the correspondimg live tardigrade had been missing. Much has been written, here in our magazine, but also in the scientific literature, about endless tardigrade searches and about the mysterious disappearence and re-appearance of whole tardigrade populations, either in samples from one and the same location or in micro-aquaria.

Searching and finding will always remain a substantial part of tardigrade microscopy. And every time you will find your first tardigrade in a new sample you might happily enjoy the thrill and marvel of its mere existence. A dissecting microscope with wide-angle eye-pieces will provide full immersion, helping us to feel like micro-divers immerged between the sand grains. But of course not all the movements in the sample will be caused by tardigrades. You will come across many species which move vividly as well:

Small water animal, living in the interstitial space between the sand grains but, admittedly, definitely not a tardigrade. Photographed through the "sand grain world window". Body length ca. 0.3 mm.

Almost close? this might be the hind part of a tardigrade ...

... wrong, totally wrong. These are merely the glassy appendices of a water plant, a so-called  diatom , as you will easily note when looking at the anterior part of the body. Nice to look at but, of course, disappointing with respect to our tardigrade search.

But after the patient search the great moment of discovery will come, this time with an exotic Thai tardigrade. Here it is:

Video (1 MB): Maritime tardigrade from Thailand, moving over a sand grain. Body length ca. 0.1 mm. Does it really make sense to call this apparently busy animal a Tardigrade (remember that the term indicates a slow moving animal)? Please note with how easily this tardigrade moves the huge sand grain to the left side!

Once you will have found one the them also the others will come in sight, e.g. this one with its huge tail appendix:

Small Batillipes sp. tardigrade from a Thai sea sand sample.
Body length ca. 0.1 mm.

We will come back to the taxonomic challenge in one of the upcoming issues. But we are quite aware that amateurs must stay modest with respect to tardigrade species determination.

© Text, images and video clips by  Martin Mach  (webmaster@baertierchen.de).
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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