Morphological changes in Schistosoma mansoni caused by the mutagen ethyl methane sulphonate

Three week old Schistosoma mansoni, cultured for up to sixty days after exposure to ethyl methane sulphonate, showed extensive ballooning which often involved most of the worm's body. Other changes included tegumental breakdown which was expressed in varying degrees from mild hernia to total disruption of body shape. Increase in gut size involved stretching of the epithelium and inclusions ranging from masses of disrupted tissue to large, dark opaque masses. Masses were also occasionally seen in the fluid filled spaces of worms. Evidence of hyperplasia was not observed in any of the histological examinations performed.