Will you go on holiday this year and will you perhaps travel to a foreign country? Possibly you might stumble there across a  tiny  material sample from a moss cushion.

Please keep in mind that some countries do not allow any export of soil and plants at all. And it goes without saying that the landscape shouldn't end up as a partial desert as a consequence of your extensive sampling.

We have enjoyed a fine holiday in beautiful Hungary a few years ago.
E.g. there is Sümeg, a small town, situated a little bit north of the Balaton lake. The sky-line is dominated by a big mountain with the fortress on top which can be reached by a steep spiral-shaped pedestrians' pathway. In front of the entry to the fortress we have collected a small moss sample from one of the sun-lit rocks. At home it turned out that a very remarkable creature lives in the moss on those rocks:

Rare tardigrade from Sümeg, Hungary.
Total view from the ventral side.
Dark field illumination.
Body length ca. 300 µm.

Another individuum of the same species.
No 'hairs' but instead a horn!

Water bear, as before,
front view, mixed light.
Note that there are in fact two horns and big, dark eyes.
Though it has a strong resemblance to one of those devil-out-of-the-cardboard-box toys it is quite alive.

The two horns can be noticed already by means of a low magnification, so their is no danger that one might overlook those items.

The first description of a tardigrade with horns goes back to the year 1906. It is only a short note in a scientific journal reporting a lecture by an early tardiologist, Prof. Ferdinand Richters (1849 - 1914) from Frankfurt, Germany:

"Prof. Richters showed two ... new Echiniscus species: Echiniscus cornutus n. sp. from the Pfalz region, with hair-like structures on the head which look like daggers and Echiniscus elegans n. sp. with a point-lace armour plate structure."

A much more elaborate description was published by Ferdinand Richters a year later, in 1907. This text is kept in a very clear and precise style. If you should be able to read German it might be worth while to order it from your local library. Here we will show by pictures what Prof. Richters explained much better by words:

"This species differs from all echiniscus water bears known so far by the structure of the two front-end 'hairs'. Whereas all other echiniscus species have fine hairs in this position, normally less than two microns in thickness (e.g. those of  Ech. wendti  with a body length of 0.24 mm are 0.125 mm long) we have in this case structures measuring only 36 µ in length but with a width of 6 µ. Broad, dagger-like structures which a botanist might call winged hairs. The central hair structure within can be still perceived and discerned from the wing type processes."

One of the horns, in close-up view. Its length is ca. 25 µm. It looks like a dagger, with an inbuilt strengthening structure and it is linked to the shoulder plate by means of a semi-rigid, slim joint.

Furthermore Richters mentions a characteristic W-shaped structure on the shoulder plate. Original text by Richters (translated):

"There is a strange distribution pattern of the grains on (plate) II. In front there is a group of grains separated from the rest by a W-shaped structure. The W spans from one horn to the other; the edges of the W have double contour lines. A medium group of grains is separated from the rear area by a slim line."

W-shaped structure and, below on the same armour plate, a horizontal smooth (non structured) line.

The typical body posture appears to be a little bit more bent when compared with other tardigrade species. All individuals from the Sümeg sample moved very slowly - real tardigrades in the sense of the word. The percentage of the tardigrades with horns in the overall population was rather low, there were much bigger groups of eutardigrades, in particular  Ramazzottius oberhaeuseri .
Overall, the tardigrades with the horns appear to be a little bit clumsy and slow but obviously they are able to live and to persist among the more lively tardigrades in the same moss cushion.

Most probably the individuals shown belong to the first species that was described within the Cornechiniscus genus: Cornechiniscus cornutus.

In the next issue we will try to search into the soul of our Cornechiniscus cornutus  by means of a some portraits and video clips for all tardigrade addicts. Stay tuned!

Literature:

Ferdinand Richters: Demonstration einiger Tardigraden und Copepoden.
Verhandlungen der Deutschen Zoologischen Gesellschaft, 1906, p. 269.

Ferdinand Richters: Zwei neue Echiniscus-Arten. Zoologischer Anzeiger 31 (1907) 197-202.

Walter Maucci (Ed.): Tardigrada. p. 165-167. Bologna 1986.

Hieronym Dastych: The Tardigrada of Poland. p. 58-59. Warszawa 1988.

© 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.

Main Page