Laboratory of Fish and Amphibian Ethology, Behavioural Biology Unit, Department of Biology, Ecology and Evolution, University of Liège, 22 Quai van Beneden, 4020 Liège, Belgium;
Via Maestra 3, 6930 Bedano, Switzerland;
Museo Cantonale di Storia Naturale, V.C.Cattaneo 4, 6901 Lugano, Switzerland;