A Florarctus tardigrade from Croatia (I)

Sometimes, when comparing images of terrestrial and marine tardigrades, we feel slightly desperate: Those terrestrial tardigrades as a rule are much easier to find and to photograph! Just look e.g. at this terrestrial Echiniscus tardigrade with its beautiful contrast and colour:

Echiniscus sp. tardigrade, still image from one of our HD videos. Body length ca. 0.25mm.

It is really a tough job to achieve similar detail and overal image quality when taking pictures of those marine species. Have a look at this tiny Florarctus tardigrade from Croatia:

But still, those marine species have charme and grace of their own. When looking at the video above you will be able to understand that this tiny animal is quite sensitive, obviously feeling uncomfortable because of the missing sand grain environment, therefore stretching out its arms to get hold of some potential substrate surface nearby. Under those circumstances it is difficult to accept that the terrestrial tardigrades are in fact considered as evolution successors of those highly developed, extremely nervous marine tardigrades.

Scepticists might suspect that this could be another animal, not a tardigrade. But the following photomicrograph makes clear the Florarctus has the same types of "antennae" as the other marine species presented here previosly. And, of course there can be no doubt about the segmented body and the eight legs which are characteristic for the phylum Tardigrada. The only strange property is the large, transparent flexible back shield - with its potatoe chip geometry.

Florarctus sp. tardigrade. Still image 1, taken from the video, in slightly higher image resolution. Body length ca. 0.15 mm.

The claws look quite similar to those of the Halechiniscidae which have already been presented in a previous magazine issue.

Florarctus sp. tardigrade. Still image 2, taken from the video, in slightly higher image resolution. Body length ca. 0.15 mm.

Note once more the habit which suggests that the tardigrade is not feeling perfectly happy in this situation. Of course, it is a philosophical question whether such an animal might actually feel happy or desperate - but we think so. In the past decades many sober scientists have come to accept that some animals might have emotions similar to us humans and that the barrier between the emotional world of animals and the emotional world of man might be less strict than assumed before.

Florarctus sp. tardigrade. Still image 3, taken from the video, in slightly higher image resolution. Body length ca. 0.15 mm.

In the next issue we will stand face to face with Florarctus. See you!

© 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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