[Interrelations in the Fasciola hepatica-water snail system]

Peculiarities of relationships in the "Fasciola hepatica-Lymnaea truncatula" system were studied by means of hystological and histochemical methods. Trematodes cause deep histopathological and histochemical changes of the injured organs of L. truncatula. They are determined by mechanical destruction of mollusc's tissues under the effect of parasites and by intoxication of animals with metabolites of parasites. Under the effect of parasites the content of glycogen and phospholipids in hosts' tissues decreases while the concentration of neutral fats increases. In most cases, however, the infected hosts remain viable that under normal ecological conditions results in the preservation of the "F. hepatica-L. truncatula" system.