HELMINTH FAUNA OF MAIN COMMERCIAL FISH IN LAKE ECOSYSTEM OF THE NAROCHANSKY NATIONAL PARK (REPUBLIC OF BELARUS)

Abstract

The composition of the helminth fauna of the main commercial fish species in the lake ecosystem of the Narochansky National Park was determined. It is represented by 10 species of helminths having a complex development cycle with the participation of intermediate hosts, as well as 1 species of helminths (Gyrodactylus sp.), a representative of cl. Monogenea, having a direct development cycle. It was noted that the highest level of invasion was typical for larvae of trematodes Tylodelphys conifera. The greatest variety of parasitic helminths is observed in fish from lake Miastro and Naroch (7 species of helminths each). It was revealed that the most common representatives of the helminth fauna of fish inhabiting the lakes of Narochansky National Park are metacercariae of trematodes of the Diplostomum genus. They were found in fish in all water reservoirs examined. Their host spectrum was also the widest. Examination of the three-spine stickleback showed a severe damage by plerocercoids Ligula intestinalis (prevalence 92% to 98.4%, infection intensity 1–4 pairs per fish). In addition, proboscis worms Acanthocephalus lucii were found in the intestines of the three-spine stickleback. The trematode fauna of fish muscles from the Naroch lake group is rather poor and represented by three types of helminths: Rhipidocotyle illense, Paracoenogonimus ovatus and Apophallus muelingi.