The population dynamics of cercariae of Schistosoma japonicum in Oncomelania hupensis.

ABSTRACT

The population dynamics and production of cercariae of Schistosoma japonicum in Oncomelania hupensis are reported. The experiments covered the whole life span of positive snails and different intervals of cercariae shedding. The results indicated that two patterns of the dynamics of cercariae shedding had been found in the life span of positive snails. The first was a long-time interval (4-7 days) and progressive decline pattern. The cercariae shedding of positive snails lasted 18-19 weeks in males and for 32-33 weeks (once a week). The second was a short-time interval (1-3 days) and continued release pattern. The cercariae shedding of positive snails lasted for 20-36 days (every day shedding). Shedding cercariae stimulate cercariae development.