The comparative enzyme and histological analysis of the Barbus peleponnesius from the aquaculture and natural population in the Vardar River in the Republic of Macedonia

Enzymatic biomarkers are sensitive to environmental changes and they respond by changing their activity. Barbus peloponnesius is considered a potential bioindicator to changes that can be caused in an environment by various pollutants. The results from the organs of the experimental group of fish from the aquaculture that were treated with a sublethal dose of insecticides (1 mg/L), showed a significant increase in the kinetic activity of the enzymes EROD and B(a)PMO compared to the group control. Whereas the group of fish treated with the same dose of herbicides did not show a significant increase, there was a kinetic activity alteration in these enzymes. A significant increase in the enzymatic activity (EROD and B(a)PMO) was also seen in the fish from the polluted Vardar River. The fish treated with sublethal concentrations (2 µg/L) of insecticides and herbicides showed haemolysis, coagulation, degeneration and cytoplasmic vacuolization of the hepatocytes, dilatation of the sinusoids, degeneration of the glomeruli and renal tubules, widening of the space between the basal membranes and the epithelial cells of the renal tubules, fracture and degeneration of the ovoplasm and disruption of the follicular epithelium in the hepatic parenchyma, kidney tissue, and the ovaries.