PATHOMORPHOLOGICAL AND CYTOMETRIC PARAMETERS OF BLOOD RED CELLS OF AGE-2 PRUSSIAN CARP (CARASSIUS AURATUS GIBELIO (BLOCH, 1782)) IN THE CONDITIONS OF INTOXICATION WITH COPPER IONS

Purpose. To detect the effect of elevated copper ion concentrations (10 aquaculture Maximum Permissible Limits) on morphological and cytometric parameters of erythrocytes of age-2 Prussian carp (Carassius gibelio Bloch, 1782) in experimental and natural conditions. Methodology. During the work, summarized results of studies performed in 2015-2016 were used. Morphological and cytometric parameters of Prussian carp erythrocytes were determined in the conditions of natural habitats (Zaporizhzhia reservoir) and an experiment. Copper ion concentration both in the experiment and natural conditions was similar and was 0.01 mg/L (10 aquaculture Maximum Permissible Limits). Experimental studies were performed during 21 days. In the control aquarium, fish were kept in the settled tap water; while in the experimental aquaria, intoxication of fish with copper ions was modelled by introducing CuSO4 in water. Blood smears were examined under 40x and 100 x magnifications with the use of microphotography (digital camera Sciencelab T500 5.17 M). Findings. The performed hematological studies showed that under the conditions of experimental chronic intoxication with copper ions (0.01 mg/L), age-2 Prussian carp had an increase in the share of immature forms of erythrocytes, increase in the number of erythrocytes with pathological signs (cell wall destruction, atypical forms), increase in the nucleus-cytoplasm ration, but the difference in cytometric parameters of erythrocytes between experimental and control fish was not significant. When comparing the morphometric parameters of erythrocytes of fish kept in experimental and natural conditions with similar copper ion concentrations (0.01 mg/L), a significant increase in the nucleus areas of mature erythrocytes was detected and, correspondingly, an increase in the nucleus-cytoplasm ratio of erythrocytes (by almost 30%) in fish in experimental conditions compared to fish, which lived in the Zaporizhzhia reservoir. An increase in these parameters indirectly indicate on the inhibition of erythrocyte functional activity. Originality. For the first time, an analysis of the effect of copper ions at a concentration of 0.01 mg/L (10 aquaculture Maximum Permissible Limits) on cytometric parameters of Prussian carp erythrocytes in experimental and natural conditions was presented. Practical value. The obtained results can be used for detecting adaptation reactions in fish organisms under the conditions of the effect of heavy metals as well as for hydroecological monitoring for detecting the levels of heavy metal pollution in aquatic ecosystems dangerous for hydrobionts.