[Morpho-anatomic and functional sectorization of Schistosoma mansoni daughter sporocysts]

During the larval development of S. mansoni in the snail host, morpho-anatomic changes occur in the daughter sporocyst by a sectorization of this larval stage. Three sectors can be distinguished: an anterior zone with a well-differentiated birth pore; dilated zones containing the developing cercariae; constricted zones without cercarial embryo. The photonic and electronic microscopical study shows variations in the tegumental structure of these sectors. This evolution of the daughter sporocysts is discussed in relation with the dynamics of larval stages and the replication process of sporocysts.