INFLUENCE OF SEX ON THE BLOOD PARAMETERS OF OHRID ROACH DURING THE SPAWNING SEASON

The aim of this study was to investigate the differences in the haematological parameters between male and female Ohrid Roach (Rutilus ohridanus Karaman, 1924), from Lake Ohrid, during the spawning season. The results showed that males have higher values than females, with statistically significant difference for the erythrocyte count, haemoglobin concentration, hematocrit and mean cell volume. These findings demonstrate that males have higher metabolic rate during this period, and that their blood physiology is influenced by the increased physical activity and very likely by the appropriate sex hormones.