EXPERIMENTAL STUDIES ON THE INTRAMOLLUSCAN DEVELOPMENT OF AN ORIENTAL LUNG FLUKE, PARAGONIMUS OHIRAI MIYAZAKI, 1939

Experimental infection of Oncomelania nosophora with Paragonimus ohirai larvae was carried out, and all the stages of the intramolluscan development of this fluke were compared with those of other species of the genus Paragonimus. The route of migration of P. ohirai within O. nosophora was also studied by means of serial sections. The main route was the lymphatic system. The inner surface of the mantle of the molluscs was the main site of penetration of the miracidia. Thereafter, the larvae migrated from there to the lymph space adjacent to the intestine, stomach, genital gland and liver. But some of the larvae were found in the tissue of the muscle or gill. It was shown that the matured cercariae migrated from the liver or genital gland through the lymphatic system to the mantle cavity and emerged through the inner surface of the mantle of the mollusc.