Ebay tardigrades (II)

In the last issue we have explained how a tiny tardigrade can fly from the Canary Islands to some remote place in Europe. Of course the tardigrade individual doesn't have a real choice where to go, when to go and whether to go at all. But when seen from the tardigrade community as a whole they are true pioneers and winners: any kind of transport will be availably for a few of them . So they can travel to any thinkable point on earth just because of the reason that they are already present almost everywhere.
Of course we should not not forget that this is a rather crude evolutionary excursion lottery where death is by far more probable than a lucky future.

You will possibly remember the  First Ebay Traveller from the Canary Islands' mosses that we had found. It has two spurs that are very conspicuous also in the dry state:

Echiniscus tardigrade from the Canary Islands.
Dry state ("tun"), photographed in air.

After immersion in water we are better prepared for a closer look at our tardigrade. Let's start with a view of the dorsal armour plates:

Echiniscus tardigrade from the Canary Islands.
Dorsal view.
Now four spines are visible.
Further lateral appendices are partially out of focus. Image width ca. 200 µm.

As we have learnt already previously the number and distribution of appendices are crucial taxonomic criteria for the exact species determination of this  Genus Echiniscus  tardigrade. In the present case the tardigrade has appendices in all possible positions apart from the "B" position. Of course, when looking at exotic moss samples even the amateur has a secret hope that one day a really unique and obviously strinkingly new species might appear in his field of view. But when looking into the taxonomic literature you will find that this particular Echiniscus tardigrade from the Canary Islands looks very much like the species which we find in many other places as well. The head region of our not-so-much-exotic tardigrade appears as follows:

Echiniscus tardigrade from the Canary Islands.
Detail: head region.
Red eyes.
Note the two long straight stylets that are fixed to both sides of the pharyngeal buulb. Even the root-like protrusions of the mouth tube within the pharynx come out clearly as well as the radial muscle pattern within the pharynx.

What else did we find in the moss? Look:

Tardigrade egg; no idea what species. Diameter ca. 100 µm.

And then we had this ethereal, water-clear wonder of living nature:

Tardigrade from the Canary Islands. Body length ca. 300 µm.

Furthermore we came across a rather unusual  Milnesium tardigradum  with an extraordinarily extended pharyngeal bulb. We have never seen something similar elsewhere.

Exotic  Milnesium tardigradum . Detail with the typical pear shaped pharyngeal bulb but with an unusual length.

And, finally we found a few extremely big tardigrades with fine, intensive reddish banding. But, as our image limit is reached within this issue we will show them next time. See you in April!

© 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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