Asian Journal of Fisheries and Aquatic Research

Pesticides are frequently used by farmers to control the pest in the agriculture fields which directly affecting the aquatic ecosystem including fishes. The present investigation was aimed to evaluate the toxicity of Cypermethrin (25% EC) a common synthetic pyrethroid pesticide frequently used in agriculture fields, in a fresh water air breathing fish Anabas testudineus in laboratory condition. The fishes were exposed to different concentration of cypermethrin and LC50 (3.2 ppm) was evaluated. Experimental fishes were exposed to different sublethal concentration (1/10 & 1/50^th of LC50 value). For the duration of 15^th, 30^th and 45 days respectively to determine some haematological parameters (RBC and WBC count, Hb percentage, PCV value). The impact was evaluated using comparative data between control and experimental groups of fishes. The RBC and WBC count, Hb percentage and PCV value were found significantly decrease (P< 0.05) in compare to control group. During exposure of Cypermethrin, some behavioural alterations such as restlessness, erratic movement, hyperactivity etc were also recorded in the exposed fishes. This was the effect of stress caused due to sudden change in the habitat or may be due to inactivation of specific enzyme acetylcholinesterase activity.