The unlikeliest of finds in a German river led aquarist David Norholm to set up a spectacular Costa Rican habitat aquarium.
IN THE QUIET outskirts of Saarbrücken, a lazy city situated where Germany ends and slowly turns into France, I began on a somewhat unconventional aquarium venture.
It all started not in the familiar aisles of a local aquarium store, but within the unassuming walls of a small business hotel—a setting not usually associated with an enchanting world of aquatic wonders. Nevertheless, it’s where this story begins. Or rather, I have to go back a little bit further. Back to the planning of this particular summer’s holidays.
Ever since I was a kid, I’ve dreamt of catching my own fish and keeping them in an aquarium. This is, however, rather difficult since I live in Denmark, where the cold winters and freezing waters make it near impossible for many fish to live in the local streams. Therefore, my excitement was palpable when I discovered that there were tropical fish living in a small closed stream in Germany.
As it turns out, there are a couple of old industrial areas in Germany, where underground heat is pumped out into a small stream, creating tropical water conditions all year round. In the 1970s, thoughtless German aquarists released several aquarium fish and plant species into the stream. The most adaptable of these species have since established themselves in a limited area, one that is not connected with other streams.
The allure of the German molly
Under normal circumstances this wouldn't be enough to pique my curiosity. However, I discovered that the common molly, Poecilia sphenops, has reverted backwards in this river over the years, eventually shedding its commercially produced aquarium (colourful) form, and is now found in its natural form with wild-type markings. This suddenly made them very interesting for me, since a wild common molly is exceptionally uncommon in stores, being virtually impossible to find in the trade.
The only problem was that this stream, named Grube Reden in Germany, is located about 1100km from my home. That made visiting it more than a random weekend project, and this is where summer holiday planning comes into the picture. This area of southern Germany and Northern France isn’t the most common holiday area, but I have a rather forgiving family.
Still, eventually I found a cozy place in France where we could spend a week’s holiday, and then stop by
