Schistosoma mansoni: scanning electron microscopy of schistosomula, adults and eggs grown in vitro.

Development of surface topography of cultured Schistosoma mansoni was followed in the cercariae, newly transformed and older schistosomula, and adults. Comparison with surface features of schistosomes from animal infections revealed no apparent differences in tegumental folding or morphogenesis, spines, sensory structures, or other components. Eggs produced by worm pairs grown in vitro were grossly abnormal, usually composed of loosely packed vitelline granules and lacking a shell.