A study of the sugar chemoreception niches of two bulinid snail hosts of schistosomiasis.

Components of the sugar chemoreception niches of two host snails of urinary schistosomiasis, namely Bulinus globosus (Morelet) and Bulinus rohlfsi (Clessin), were measured by using a buccal mass olfactometer. Among the polysaccharides tested, amylose was found to be the strongest phagostimulant for adults and juveniles of both snail species. Other phagostimulants identified were maltose and xylose for B. rohlfsi and maltotriose for B. globosus. The a(1-4)-glucosidic linkage and the presence of glucose residues were found to be key factors in the stimulus recognition system of the snails. The possible use of these findings in the design of controlled-release formulations for the selective removal of schistosome host snails is considered. The ecological implications of these studies are also examined.