Maritime tardigrades (VI) - once more: adhesive toes

Maritime tardigrades are difficult candidates for filming. Nevertheless we are going to present a video of a maritime  Batillipes  tardigrade living in a beaker on our windows-sill. The video indicates, once more, that "tardigrade" (slow-walker) is a rather strange name for some species within this phylum as they can be characterised as rather nervous and hastily moving animals. The Batillipes speed is similar to the quickly moving terrestrial, carnivore tardigrade species Milnesium tardigradum. Tardigrade scientist Ernst Marcus measured a Batillipes walking speed of about 100 µm per second.

Though being a true nano miracle, measuring a mere 0.1 mm in body length Batillipes  reveals a complicated interaction with its environment, and, as already stated, a rather nervous behaviour. Besides we note that there is the ability to move backwards (Film: ca. 2.5 MB).

This video was terribly difficult to produce. First of all it is not possible to transfer the tardigrades from a glass surface to an other glass container because they tend to stick to it like cemented. Furthermore the tardigrades are secerning a kind of glue and tend to fix detritus particles to their body surface area, looking very unhappily in this state.

There are some tardigrade videos to be found in the internet meanwhile. But Batillipes videos will remain scarce because of the reasons mentioned above. Television productions often are on low budget (because their own staff is terribly expensive ;-). So, as a rule they cannot afford to pay for the additional cost-increasing difficulties in tardigrade filming. Instead, you have the respective video here, for free.

In order to better explain the glue problematics we are going to show a much bigger image than usual where you will be able to notice the glue traces more clearly:

Batillipes sp. tardigrade with glue traces. The glue traces have a diameter of about 1 µm (1/1000 of a millimeter) and an average length of about 5 µm. Typically we note one trace per adhesice disc.

Frankly spaeking we do not know how to proceed at this point. Apparently nobody has actually found the assumed glue providing glands and their openings though they were predicted by scientists. And we didn't come across a discussion of this topic in the more recent scientific literature. Possibly we missed something, or it has been remaining a secret up to the present day. Overall the traces look like tooth paste or liquid glue which remains in its original geometry for some time even in water. Perhaps the tardigrade gets rid of its "glue connection" just by advancing the glue fiber?
We would be very much interested in additional information from our audience.

© 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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