Species of trout (Salmo spp) were recorded in most lakes surveyed by Projet Lac. Salmo spp dominated the fish biomass in the littoral and benthic zones of the alpine lakes Sils and Poschiavo. In the perialpine lakes, trout were most frequently caught in the inflowing streams and rivers. In Zug, Hallwil, Lower Constance, Chalain and Lucerne trout were only caught in adjacent streams and rivers, and not in the lake itself. Large, silvery lake forms of Salmo trutta caught in the pelagic zone (“lake trout” sometimes called S. trutta forma lacustris) were most common in Lake Geneva, with some also caught in lakes Walen, Upper Constance, Brienz, Sarnen, Neuchatel, Morat, Saint-Point and Joux.