Assessment of hematological indicators, histological alterations, and DNA damage in Danube sturgeon (Acipenser gueldenstaedtii) exposed to the organophosphate malathion

This study focused on organophosphate malathion toxicity in Danube sturgeon (Acipenser gueldenstaedtii) and its negative effects in sub-lethal concentration. In this context, the LC50 value of fish exposed to five different concentrations and two different sub-lethal concentrations depending on the LC50 value were considered. Accordingly, LC50 of malathion for 96 h was 3.24 mg L^-1. In leukocyte (WBC) and hemoglobin (HGB) such as hematological indicators, significant differences were observed in sub-lethal concentration (One-eighth of the LC50 =0.4 mg L^-1). In addition, serious histological alterations were observed in the gill and liver tissues after both acute (96 h) and chronic periods (28 days). While epithelial lifting and hyperplasia were the most prominent lesions in the gill, intense vacuolization were observed in the liver. In addition, circulatory disturbances, regressive changes, and progressive changes in the gill and circulatory disturbances and inflammation in the liver were significantly higher for the chronic period. Finally, significantly higher DNA damage was detected in fish exposed malathion in the chronic period compared to the control group. In conclusion, the present study has proven that malathion has a hematological, histological and genotoxic effect on the endangered species A. gueldenstaedtii. Thus, the current study will motivate for residue studies on A. gueldenstaedtii and trigger conservation strategies for local governments.