Diversité spécifique et écologie des mollusques continentaux de la basse vallée du Ferlo (Sénégal)

The reflooding of the Lower Ferlo Valley since 1988 after 32 years of drying up has caused an increase in the number of aquatic molluscs. Inventories of the Lower Ferlo Valley mollusks were carried out. Nine species representing eight genera and seven families were recorded: Bellamya unicolor Olivier, 1804; Coelatura aegyptiaca (Cailliaud, 1827); Corbicula fluminalis (Müller 1774); Heleobia sp, Melanoides tuberculata Müller, 1774; Biomphalaria pfeifferi (Krauss, 1848); Bulinus forskalii (Ehrenberg, 1831); Bulinus truncatus (Audouin, 1827) and Lymnaea natalensis Krauss, 1848. Melanoides tuberculata is dominant on bottom deposits, while Biomphalaria pfeifferi, Lymnaea natalensis and Bulinus truncatus predominates on aquatic plants. Salinity and aquatic vegetation appear to play an important role in mollusc occurrences. Among identified species, four are involved in the transmission of human and animal trematodosis: Biomphalaria pfeifferi (human intestinal schistosomiasis with Schistosoma mansoni), Bulinus truncatus (human urinary schistosomiasis with Schistosoma heamatobium and animal paramphistomosis with Paramphistomum microbothrium), Bulinus forskalii (animal schistosomiasis with Schistosoma bovis and animal paramphistomosis with Paramphistomum phillerouxi) and Lymnaea natalensis (animal fasciolasis with Fasciola gigantica).