The acute toxicity of benzalkonium bromide, crystal violet, methylene blue, formaldehyde, potassium permanganate, zincsulfate, benzyl chloride and sulfamonomethoxine sodium to Pseudovorticella jiangi and the acute toxicity of benzalkonium bromide tomegalopa and P1 of Eriocheir sinensis were studied with routine biological toxicity method under the condition of indoor with still water.The results showed that the 24 h LC50 of eight kinds of drug on P. jiangi in order were crystal violet 0.18 mg/L, benzalkonium bromide0.26 mg/L, potassium permanganate 1.53 mg/L, benzyl chloride 1.81 mg/L, zinc sulfate 2.31 mg/L, methylene blue 3.53 mg/L,sulfamonomethoxine sodium 5.96 mg/L, formaldehyde 23.04 mg/L, respectively. The 2 h LC50 of benzalkonium bromide on P. jiangi was6.57 mg/L. The 2, 12, 24, 48, 72, 96 h LC50 of benzalkonium bromide on megalopa were 54.78, 14.81, 5.5, 3.64, 2.78, 2.94 mg/L, respectively,4.02 mg/L, respectively, and the SC was 0.65 mg/L. The drug screening was based on the principle of security, high efficiency, economicand conveniency, we chose benzalkonium bromide as the drug for the prevention and control of P.jiangi, at the period of megalopa and P1,we adviced that the dosage of splashing concentration was 0.35 mg/L and the dosage of bath therapy was 8.0 mg/L for 2 hours. |