[Study on molluscicidal effect of chlorosalicylicamide].

OBJECTIVE: To observe the molluscicidal effect of chlorosalicylicamide on Oncomelania hupensis and toxicity on fishes. METHODS: Different concentrations of chlorosalicylicamide were prepared, and immersion and spraying methods were used to test its molluscicidal effect and toxicity to fishes. Niclosamide ethanolamine salt was used as control. RESULTS: Under water temperature of 28 C with the dose of chlorosalicylicamide at 0.25 mg/L and 0.4 mg/L, the mortality rate of snails by immersion was 97.8% and 100% respectively after 48 h, and the LC50 was 0.0674 mg/L. While for niclosamide at the same doses, the mortality rate of snails was 22.2% and 66.7% respectively, and the LC50 was 0.397 6 mg/L. With the concentration of 0.4 mg/L for 72 h, the fish death rate in chlorosalicylicamide and niclosamide was 50.0% and 100% respectively. CONCLUSION: Chlorosalicylicamide shows a molluscicidal effect on Oncomelania snails and a lower toxicity to fishes than that of niclosamide.