Syed Athar Husnain Kazmi¹, Rehana Iqbal^1*, Amin A. Al-Doaiss^{2, 3}, Muhammad Ali⁴, Riaz Hussain^5*, Fariha Latif¹ and Ghulam Ali Raza⁶

Azoxystrobin (AZX), also known as Amisida, is a widely used medication for treating and managing fungal diseases in agriculture. The hazardous effects of azoxystrobin on non-target organisms, particularly fish have generated significant attention for its toxicological study since it penetrates in aquatic environment from several locations. The toxicity of azoxystrobin on experimental fish was investigated in this study using a variety of biomarkers including hematology, antioxidant enzymes, oxidative stress indicators, histopathological alterations in gills, and various morphological and nuclear changes in erythrocytes. Sixty-four (64) freshwater fish reared in aquaria containing water were randomly divided into four treatment groups (T0 and T1-T3). All the fish were exposed to AZX at different concentrations (60.0, 80.0, and 100 μg/L) to determine the harmful effects of AZX. All the fish except in control (untreated) group received the AZX treatment for the period of 42 days. Hematology results showed reduced erythrocyte and hemoglobin values and higher total and differential leukocyte values. The findings showed that treated fish had considerably higher levels of various oxidative stress biomarkers in gills while lower levels of total proteins and antioxidant enzymes (catalase, superoxide dismutase, peroxidase and reduced glutathione). This research exhibited that certain nuclear abnormalities (erythrocytes with condensed, lobed nuclei, and erythrocytes with micronuclei, and morphological alterations (erythrocytes with spindle shape, pear shape, and spherocyte) were significantly increased in the erythrocytes of the experimental fish. AZX induced microscopic abnormalities in gills of different treated fish. Our experimental study suggested that AZX disturbs physiological and biochemical markers at higher concentrations.