CYPRINID FISH INFECTION WITH METACERCARIAS OF TREMATODES UNDER ANTHROPOGENIC EFFECT

Abstract

We presented parasitological studies of fish (Cyprinidae) in the Usman River within the Voronezhsky Biosphere Reserve. The infection of fish with metacercarias of trematodes in the river sections with various anthropogenic effect was assessed. We identified metacercarias of 6 species of trematodes: Opisthorchis felineus, Pseudamphistomum truncatum, Metorchis bilis, M. xanthosomus, Posthodiplostomum cuticola, and Paracoenogonimus ovatus. The highest occurrence and abundance of P. cuticola (95.4%, 36.4 sp.) and P. ovatus (56.9%, 8.8 sp.) was noted in the upper reaches of the River, in areas with high anthropogenic impact. An increased prevalence of infection was recorded for the group Opisthorchiidae (O. felineus, P. truncatum, and M. bilis) in areas within the Reserve with minimal anthropogenic impact. Infection rate of Opisthorchiidae metacercarias was 86.5% and 8.2 specimens in the middle and lower reaches of the River. At the same time, we noted a decrease in infection with P. cuticola (54.5%; 5.8 sp.) and P. ovatus (33.9%; 1.3 sp.). The degree of anthropogenic eutrophication of the Reservoir affects the development of different species of mollusks and the infection of fish with metacercarias. Metacercarias of trematodes can be used as indicators of water pollution in assessing anthropogenic effect on natural ecosystems.