Physiological and histopathological alterations in Capoeta baliki and Squalius pursakensis after caused by some environmental pollutants

The present study was aimed to apply physiological and histological biomarkers of pelagic and benthic fish species as biomonitoring of environmental pollutants. Capoeta baliki and Squalius pursakensis were caught from 5 stations in Kirmir Stream (Turkey). After measuring the total length and weight for condition factor analysis, liver, gill, brain, and kidney tissues of fish were taken for histopathological analysis. Dorsal muscles of fish tissues were analyzed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). The mean condition factor of C. baliki and S. pursakensis were 1.14 and 0.97, respectively. It was indicated that the first one was in good condition than the latter one. According to histopathological observations, the alterations in the tissues may be associated with the environmental pollutants' exposure. The total concentration of PAHs of dorsal muscle of C. baliki and S. pursakensis found ranged from 0.915 to 108.421 mu g/kg and 0.601 to 675.248 mu g/kg, respectively. The highest total concentrations of OCPs were found as 44.16 mu g/kg for C. baliki and as 562.12 mu g/kg for S. pursakensis. The PCB 28 (10.83 mu g/kg), PCB 52 (10.92 mu g/kg), PCB 138 (226.24 mu g/kg), and the total concentrations of PBDEs were found as 151.74 mu g/kg in only S. pursakensis. The result of the concentrations of the investigated pollutants was generally found higher in S. pursakensis which is a higher trophic level than C. baliki. Histopathological alterations were detected as hyperemia in liver, gill, and brain; as hydrophobic degeneration in liver; hyperplasia in gill; and tubular degeneration in kidney tissues of both species. The obtained result of the study shows that the environmental pollutants may affect the physiological and histological status of fish.

Automated summary

This study aimed to assess the effects of environmental pollutants on fish species by analyzing physiological and histological biomarkers. The results showed that the condition of Capoeta baliki was better than Squalius pursakensis, and higher concentrations of pollutants were found in S. pursakensis. Histopathological analysis revealed alterations in liver, gill, brain, and kidney tissues of both species. The study highlights the potential impact of environmental pollutants on the physiological and histological status of fish.