Dynamics of the parasitofaauna of roach Rutilus rutilus (Linnaeus, 1758) since the beginning of the existence of the Boguchanskoye reservoir

Abstract

This article presents the results of parasitological studies of roach Rutilus rutilus (Linnaeus, 1758) in Boguchanskoye reservoir, the stages of parasite fauna formation and the current state of the reservoir. Ichthyofauna of Boguchanskoye Reservoir was formed by local fauna of Angara River. Transformation of the original reservoir has led to significant changes in the composition and community structure of all groups of organisms of aquatic biota and affected the parasite fauna of fish. Over eight years (2012–2020), 35 species of parasites from 9 classes were recorded in roach in Boguchanskoye Reservoir. Originally, the composition of parasites was not diverse and had few specific species. Most parasites had low or single occurrence. Trematode metacercariae predominated, and their quantitative indicators (extensity of infection and index of abundance) indicate the ecological confinement of fish to shallow river sections. After impoundment, the parasite fauna composition became more diverse due to parasitic protozoa and monogeneas. Currently, the proportion of parasites with a direct development cycle is 68.2%. In 2020, two types of helminths were registered with a plankton development pathway: Ligula intestinalis Linnaeus, 1758 and Philometra rischta Skrjabin, 1917. The species Ph. rischta — first detected in fish in water bodies of Krasnoyarsk Region. There was a change in the dominant species, Dactylogyrus crucifer (Wagener, 1857) became the dominant species.