1. CNRS-ESA 5023 Ecologie des Hydrosyste mes Fluviaux, Université Claude Bernard Lyon, 1, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
2. Department of Biology, Faculty of Art and Science, University of Dicle, 21280 Diyarbakir, Turkey
3. Museo Nacional de Ciencias Naturales, José Gutiérrez Abascal, 2 E-28006 Madrid, Spain
4. Department of Biology, Armenian State Pedagogical Institute, Khanjyan 5, 375010 Yerevan-10, Armenia
5. Department of Biology, Washington University, St Louis, MI 63130-4899, USA