Acute toxicity of the chloroacetanilide herbicide butachlor and its effects on the behavior of the freshwater fish Tilapia zillii

Didigwu Nwani Christopher, Ibiam Ama Udu, Okoh Florence, Obasi Oji Uche, Chima Ogbonyealu Rebecca, Agha Arua, Ibiam, Udu Ibiam Onyinyechi
2013 African Journal of Biotechnology  
Acute toxicity of butachlor, a chloroacetanilide herbicide (2-chloro-N-[2, 6-diethylphenyl] acetamide) to Tilapia zillii, was studied in a semi static bioassay. The 24, 48, 72 and 96 h LC 50 values (with 95% confidence limits) estimated by probit analysis were 3.13 (2.88 to 4.61), 1.93 (0.63 to 4.41), 1.27 (0.59 to 1.92) and 1.25 (0.60 to1.85) mgl -1 , respectively. There were significant differences (p<0.05) in the LC 50 values obtained at different exposure times and the safe levels estimated
more » ... by different methods varied from 1.25×10 -1 to 1.25×10 -5 mgl -1 . There were dose and time dependent increase in mortality rate due to exposure to the herbicide. Stress signs in form of hyperactivity, erratic swimming, skin discoloration, vigorous jerks of the body followed by exhaustion and death were observed. The 96 h LC 50 of 1.25 mgl -1 obtained indicate that the herbicide was toxic to T. zillii. Agricultural use of butachlor in the environment, especially, near water bodies, must be restricted to avoid the severe risk associated with the use of the pesticide.
doi:10.5897/ajb12.2433 fatcat:hdd3jyp3gve5zbcpwyayc7c7a4