Acute Toxicity and Behavioral Changes of the Gold Fish (Carassius Auratus) Exposed to Malathion and Hinosan

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.