Neurobehavioral responses of the freshwater teleost, Cyprinus carpio (Linnaeus.) under quinalphos intoxication

Effect of quinalphos on the freshwater fish, Cyprinus carpio to elucidate inhibitory effect of quinalphos on acetyl cholinesterase activity associated behavioral changes. Fishes were exposed to one fifth (0.15µg/l) and one tenth (0.75 µg/l) of the lethal concentration (7.5 µg/l) of quinalphos for a period of 1, 7 and 14 days, and were allowed to recover for 7 days. Maximum decrement in acetyl cholinesterase activity of the exposed fish was recorded in brain followed by muscle, gill and liver. Recovery tenures witnessed increment in acetyl cholinesterase activity but significantly differed in comparison with control group. Depression of acetyl cholinesterase activity suggests decreased cholinergic transmission and consequent accumulation of acetylcholine in the tissues leading to cessation of nerve impulses. This has lead to behavioral and morphological changes due to impaired neurophysiology of the fish.