Abstract:

Chlorpyrifos is an organophosphorus pesticide widely used in agriculture. This study was aimed to determine the acute toxicity of chlorpyrifos on the common carp (Cyprinus carpio). In addition, behavioral changes at each chlorpyrifos concentration were determined for the individuals. Juvenil fish (C. carpio) were selected for the bioassay experiments. The concentrations of chlorpyrifos (0.10, 0.50, 1.50, 2.50, 3.50 mg/L) which was determined with o preliminary study were applied for 96 hours. Water temperature was regulated at 23±1 C. Data obtained from the chlorpyrifos acute toxicity tests were evaluated using the Probit Analysis Statistical Method based on Finney`s Probit Analysis using a computer program. The 96-h LC50 value for the common carp was estimated as 2.08 mg/L. Observed behavioral changes were typical of neurotoxin: less general activity than control group, loss of equlibrium, erratic swimming and staying motionless at a certain location generally at mid-water level for prolonged periods.

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