Parasitic castration in the snail-trematode relationship can be understood as any change in the reproductive function of the snail that is due to interference by the developing larvae inside the snail that leads to the reduction or complete disruption of egg-laying activity. This study was designed to observe the parasitic castration of Biomphalaria glabrata infected with Schistosoma mansoni during both the pre-patent and patent periods. The effect of infection on snail fecundity and fertility, growth rate and survival was studied during the 62 days following miracidia exposure. An integrated approach was employed that used biochemical and histological tools over the same period.