[Experimental study on compatibility of three species of freshwater snails with Angiostrongylus cantonensis].

OBJECTIVE: To compare the compatibility of three species of freshwater snails, Pomacea canaliculata, Cipangopaludina chinensis, Bellamy a aeruginosa, with Angiostrongylus cantonensis. METHODS: The snails were infected by the first-stage larvae of A. cantonensis under the same conditions. Twenty snails of each species were randomly sampled after exposed to the larvae for 1, 3, 6, 12, 24 hours, respectively. Each group was placed into an aquarium. Each species with same number was established as control. All the aquaria were equipped with a filter, the water temperature was kept at (24 +/- 1) degrees C. In the first two weeks, the number of death was recorded. Later, the snails were successively examined to record the weight and worm burden of each snail. RESULTS: Some snails were dead which mainly happened in the first week postinfection. The death rate and infection rate were not associated with exposure time and snail species. Worm burden of P. canaliculata was significantly higher than the other two species, however, the worm density of P. canaliculata and B. aeruginosa was not significantly different but higher than that of C. chinensis. The worm burden and worm density of P. canaliculata and B. aeruginosa, respectively, were significantly different among five exposure-time groups, but that of C. chinensis was not. CONCLUSION: All the three snail species show a high compatibility with A. cantoneasis. In general, the compatibility of P. canaliculata is superior to the other two species.