Responses of the freshwater fish Cyprinus carpio exposed to different concentrations of butachlor and oxadiazon

Abstract

The toxic effects of butachlor and oxadiazon, widely used herbicides in South Korea were evaluated in the common carp Cyprinus carpio. Fingerlings of C. carpio were exposed to 0.5, 5 and 50 µg L-1 concentrations of herbicides for 96 h under static bioassay method and hematological and biochemical parameters were assessed. At all concentrations of butachlor and oxadiazon, white blood cell (WBC), serum sodium (Na+), chloride (Cl-), glucose, cholesterol and triglyceride levels were significantly (P < 0.05) increased compared to that of their control groups. Mean cellular volume (MCV), mean cellular haemoglobin (MCH), potassium (K+) and alkaline phosphatase (ALP) levels were significantly increased in all the concentrations of oxadiazon exposed groups. Total protein, albumin and globulin levels were induced in butachlor treated fish. Both the herbicides caused a decrease in haemoglobin (Hb), hematocrit (Hct) and red blood cell (RBC) counts in all the concentrations. However, no significant changes were found in the mean cellular haemoglobin concentration (MCHC) levels. The importance of these parameters in monitoring of the aquatic ecosystem contaminated with pesticides is discussed in detail. Furthermore, chronic effects of these herbicides on these parameters along with other parameters such as hormonal and histopathological studies need to be investigated in the future studies.