1. Department of River Ecology and ConservationSenckenberg Research Institute and Natural History Museum Frankfurt Clamecystrasse 12 63571 Gelnhausen Germany
2. Department of Integrative BiologyOregon State University 3029 Cordley Hall Corvallis OR 97331 U.S.A.
3. Department of Aquatic EcologyUniversity of Duisburg‐Essen Universitätsstrasse 5 45141 Essen Germany
4. Institute of Ecology, Evolution and DiversityGoethe University Frankfurt am Main Germany
5. Environmental Campus BirkenfeldUniversity of Applied Sciences Trier Post Box 1380 55761 Birkenfeld Germany
6. Faculty of BiologyUniversity of Duisburg‐Essen Universitätsstrasse 5 45141 Essen Germany