Abstract
SUMMARY: Daughter sporocysts (SpII) of Schistosoma bovis produced by the mother sporocyst (SpI) can direct their production along three different pathways during intramolluscal development. (i) Direct sporocystogenesis–tertiary sporocysts (SpIII) are directly produced by non-cercariae producing daugher sporocysts (SpIII). (ii) Simultaneous sporocystogenesis and cercariogenesis–SpIII are produced by Spil in which cercariae are being produced. (iii) Sporocystogenesis after cercariogenesis-Spill are produced by SpIl in which cercariae are undergoing degeneration. These mechanisms can be interpreted in terms of demographic strategy leading swiftly to the taking over and optimum exploitation of the host's hiotic capacity.