Abstract: Objective To observe the acute toxicity in ducklings resulted from intake of crucian contaminated by sus- pension concentrate of metaldehyde and niclosamide(MNSC) for technical support for snail control with drugs in our prov- ince. Methods Twenty duckings of 60 days old were randomly divided into test group and control group. Ducklings in the test group were given crucian killed by MNSC in effective dose of 20 g / L, and those in the control group were fed with crucian naturally died from water. Each duckling in both groups was dosed with 40 g of the fish meat, and observed for the simultaneous reaction upon intake and increase of body weight one week after intake. Results No toxic reaction occurred in the ducklings in the test group in 6 h after intake, and the average body weight remained no significant difference before test(t = -0. 873, P= 0. 394) and after test( t = 0. 973, P = 0. 343) in both groups. Conclusion Acute toxicity of MNSC appears free in our ducklings after intake of the contaminated crucian.

Key words: Suspension concentrate of metaldehyde and niclosamide, Duckling, Acute Toxicity