Effect of Cypermethrin on Brain Acetylcholinesterase Activity In The Indian Major Carp Labeo Rohita

The toxic effect of cypermethrin on the acetylcholinesterase activity of Labeo rohita was studied. The fish were exposed for 24- 48, 72 and 96 hours in 10 and 20% sub lethal concentrations of 96 h LC50 of cypermethrin (0.057 ppm). Exposure of fishes to 10% and 20% sub lethal concentrations of cypermethrin caused severe changes in the acetyl cholinesterase activity. Highest activity was observed in the fish exposed to 20% sub lethal concentration during 24 hour. Highest inhibitory effect was noticed in the fish exposed to 20% sub lethal concentration of cypermethrin.