摘要：The acute toxicity of tobacco (Nicotiana tobaccum) leaf dust, on the juvenile African catfish(Clarias gariepinus) was assessed in a static renewal bioassay system for 96 hours. Fivegraded concentrations of tobacco leaf dust were prepared as 25.00, 20.00, 15.00, 10.00, 05.00mg/l and a control experiment (0.00mg/l). The 96hour LC50 value was 10.96mg/l, r2 value of0.68 with 95% lower and upper confidence limit of 7.50 and 16.00 mg/L respectively. At variedconcentrations of tobacco leaf dust, the fish showed erratic swimming, secretion of mucus,respiratory distress, and darkening of skin. Mortality was recorded in all concentration oftobacco leaf dust tested.
