Distribution of Fresh-Water Mollusks of the Gharb Area (Morocco)

To assess changes in the fauna of freshwater mollusks in the Gharb Plain (Morocco), 200 sites spread over five districts were surveyed between May 2012 and May 2013. A total of 11 species were identified. Physella acuta and Melanopsis praemorsa were most frequently encountered. Bulinus truncatus, an intermediate host of schistosomiasis in Morocco, and Planorbarius metidjensis, an intermediate host of schistosomiasis, were not harvested. The absence of these species may be due to a combination of climatic, biological and anthropogenic factors related to the changes that have occurred in the region.