The histopathological effect of metacercariae of the genus Brachylaima on the land snail, Monacha obstructa.

The histopathological changes in the kidney of the land snail Monacha obstructa and the histochemistry of the body wall of the parasite were studied. The histological pictures of the infected kidney showed extensive degree of degeneration in the renal tissue with multiple necrotic foci. Due to the mechanical and feeding effects of the parasite, the renal lamellae were disintegrated. Also, suckers increased the renal damage. In some levels of the kidney, the renal tissue was completely disappeared except the connective tissue of kidney capsule. Also, it was observed that there was a clear space between the parasites and renal tissue probably as a trial of evasion from the Host's reaction. The histochemical study on the metacercarial body wall revealed that it is consisting of three layers arranged as outer, middle and inner layers. Staining with Periodic Acid Schiff proved that the body wall is rich in mucopolysaccharide content. The idea that this parasite can be used as a biocontrol agent is also discussed.