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Background: Pesticides are widely used in agriculture. Excessive use of pesticides has health risk for human and threatens non-target organisms. This research aimed to determine lethal concentrations of malathion and Hinosan for Carassius auratus (5±1 gr) [mean ± SD].
Methods: Experiments were performed according to O.E.C.D for 4 days (96 h) and concentrations of 0, 1, 2, 4, 8 mg L-1 Hinosan and 0, 1, 2, 4, 16 mg L-1 malathion with three replicates. LC1, LC10, LC30, LC50, LC70, LC90 and LC99 for 24, 48, 72 and 96 h were determined using a probit analysis.
Results: The results indicated that the 96 h LC50 value of Hinosan and malathion for Gold fish was 4.02 and 4.71 mg/L, respectively. Fishes exhibited irregular, erratic and darting swimming movements, hyper excitability, bruise in the caudal section, loss of equilibrium and sinking to the bottom.
Conclusion: Malathion and Hinosan have medium toxicity for C. auratus and could cause irreversible harm and behavioral changes.