Krapanj (I)

Well, what are the motifs of holiday travelling? Scientists of the so-called soft disciplines or humanities have struggled to find out. But virtually all of us will have some potential explanations at hand: the search for the ultimate holiday romance, an escape from routine or boredom at home, the cold weather in the northern regions, the mediterranean food, sitting and eating outside - and, yes, perhaps, some hope to improve our own culture and education. Of course, one of the rarest motifs will be the search for tardigrades.

So, to sum up, the travelling destinies will be a kind of mirror of our souls.

The destiny of holiday travelling - a mirror of our souls. The photograph is depicting a window pane at the harbour promenade of a small Croatian island called Krapanj. Plastic windows and even an ample use of cement on historic buildings are not able to destroy the charm of this beautiful island situated at about 300 m from the coast. Strange enough plastics and cement blend in harmonically with the beautiful appeal of the scenery.

Our holiday desires come linked with holiday souvenirs. Decades ago a rosewood spoon with some burnt-in pattern - perfectly useless - provided a souvenir fit. Nowadays there are many more souvenir flavours. And there is a good chance that some of our readers will have a tendency to collect dry sand samples.
In contrary, the tardigrade microscopist will collect wet sand samples and sea water, transport those materials very carefully in order to place them into a transparent polstyrene container at home. Cool conditions, no sun, one year of sea water microscopy guaranteed. This is really amazing when keeping in mind the investments which are deemed necessary in order to keep up one of those big seawater aquariums with a few fishes in it. The trick is just to understand that our sea water aquarium is a kind of minimalistic aquarium. No organism beyond one oder two millimeters in size allowed! A kind of desert but still somewhat alive.

Our micro aquarium under the stereo microscope. It has to be kept closed in order to avoid evaporation. Marker lines on the sidewall of the aquarium serve as a control instrument. We use only cold LED light for illumination in order to keep the temperature as low as possible. For example, a cheap IKEA "Jansjö" LED lamp will provide a sufficient quantity of cold light.

When the water level is not too high (below ca. two or three centimeters) it is possible to study the sand grain scenery even directly through the water. Once a tardigrade is found it can be pipetted into a smaller container - like the one shown below - for temporary study and put back afterwards.

A small coin collector container micro aquarium as seen under the stereo microscope. Please note the freely standing ("floating") water column with some sand grains in the center of it.

The coin container aquarium is not suited for continued tardigrade study as its water volume is not sufficient, in particular with respect to oxygen content. A further reason is that the tardigrades have to clean their bodies by moving amongst the sand grains. The coin container aquarium will provide a reasonable photo quality at low and medium magnification - just have a look at the image example below. But please keep in mind that this is an uncomfortable situation for the tardigrades!

We were lucky enough to find a new maritime tardigrade paradise, namely the island of Krapanj in Croatia. One big advantage of Krapanj (among many others) is the fact that tourists' cars are not allowed. Perfectly quiet.

One of the ferries between the mainland and the Krapanj island. Its name ("Spuzvar") reminds of the Krapanj island sponge diver tradition which is still kept alive. The ferry distance is about 300 m, one of the shortest ocean ferry lines worlwide.

When seen from the mainland the island doesn't look very impressive. That's the reason why most tourists are not able to recognize its qualities and beauty. It is a hidden beauty to enjoy.

The harbour promenade of the Krapanj island, as seen from the Croatian mainland. The inhabitants of the island keep complaining about its under-development. We think that this under-development is quite beautiful and rare and that the island should stay that way.

We spent a week in a marvelous small pension, situated just a few meters from the ocean.

View from our Krapanj terrace towards the ocean.

There are large areas of shallow sea water around the Krapanj island with lots of life in them. Even those rare (and law protected) plug shells occur everywhere around Krapanj. This is the kind of water habitat where we can search for tardigrades as well.

Plug shell in shallow water at the shore of the Krapanj island, as seen from the harbour promenade. Please keep in mind that those shells are protected by law.

Well, here is one of the Krapanj tardigrades:

Florarctus tardigrade from the island of Krapanj, Croatia. Body length ca. 0.15 mm.

As far as the anatomy of those Krapanj tardigrades is concerned we have to ask for your patience. They are very small, so small that we had difficulties in the beginning even to discern between their front and hind ends!

© 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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