DEVELOPMENTAL STABILITY AND CYTOGENETIC HOMEOSTASIS OF FISH FAUNA OF THE SLUCH RIVER IN CURRENT CONDITIONS OF ANTHROPOGENIC STRESS

Purpose. To assess the developmental stability and cytogenetic homeostasis of fish populations in the Sluch River in the watercourse areas subjected to anthropogenic stress of different intensities. Methodology. Studies of fish populations in the Sluch River were carried out within Berezne district of Rivne region. The condition of individual fish in the populations were evaluated integrally using morphological (evaluation of the stability of development based on the level of fluctuating asymmetry (FA)) and cytogenetic (micronucleus (MN) test of peripheral blood erythrocytes of fish) methods. The methods used allowed identifying the destabilization level of organism development, even in the cases when there is no direct disturbance of population homeostasis. Findings. The found FA levels reflect minor (initial) deviations from the normal developmental processes of fish populations in in the studied watercourse areas. Especially significantly this is reflected in a high proportion of individuals with FA in the samples of roach, bleak, bream and perch. An excess in the frequency of MN erythrocyte cells in roach and pike blood relatively the level of spontaneous mutagenesis was observed in the cross section #2, which is exposed to sewage waters. The observed manifestation of degenerative processes in fish organisms at this stage can be evaluated as an increased reactivity of sensitive species to the presence of mutagenic agents in the composition of river pollution. The functioning of spawning populations gives reason to believe that the current level of human impact is not critical for the hydroecosystem. Originality. For the first time we obtained data on the stability of development and cytogenetic homeostasis of fish populations in the hydroecosystem of Rivne region in current conditions of anthropogenic stress. Practical value. The obtained results can be used for assessment and prognoses of wild fish stocks of the investigated hydroecosystem and can be taken into account when planning water protection activities within the river basin.