a1 Department of Zoology, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB9 2TN, Scotland, UK
Experiments were performed to study the effect of age and lifespan on the infection success of Diplostomum spathaceum miracidia. Specimens of Lymnaea peregra and L. stagnalis were individually exposed to single miracidia of D. spathaceum of different ages under conditions of constant illumination at 20°C. The life-span of the free-swimming miracidium of D. spathaceum is 24 h at 20°C. It was observed that as the miracidium ages, its ability to successfully infect snails declines rapidly.
(Accepted October 22 1990)
p1 Present address: Department of Zoology, University of Port Harcourt, P.M.B. 5323, Port Harcourt, Nigeria.