or this ...
http://www.danubeday.org/dday06/en/danube_fish .htm
The Danube streber (Zingel Streber) is yellow-brown in colour and has several dark bands crosswise along its body. The average length is approximately 15cm, but it can grow to over 18cm long.
The Danube streber is found in fast-flowing river stretches. It becomes active after sundown when it searches for food. A remarkable characteristic of the Danube streber is its ability to hold itself on the riverbed, against even the strongest currents. It feeds almost exclusively on organisms that are driven near it by the water.
seems to be a river fish only?