Acute toxicity of mebendazole, deltamethrin and copper sulphate to Alosa sapidissima

The acute toxicities of mebendazole, deltamethrin and copper sulphate to Alosa sapidissima were studied by static water tests. At 15 ℃, 20 ℃ and 25 ℃, the 96 h median lethal concentrations (LC₅₀) of mebendazole to A.sapidissima were 0.226 mg ·L^-1, 0.077 mg · L^-1 and 0.122 mg · L^-1, and safe concentrations (SC) were 0.194 mg · L^-1, 0.027 mg · L^-1 and 0.063 mg ·L^-1, respectively. The 96 h-LC₅₀ of deltamethrin were 0.386 μg · L^-1, 0.234 μg · L^-1and 0.259 μg · L^-1, and SCs were 0.090 μg · L^-1, 0.061 μg · L^-1and 0.082 μg · L^-1, respectively. The 96 h-LC₅₀ of copper sulphate were 0.320 mg · L^-1, 0.385 mg · L^-1 and 0.186 mg · L^-1, and SCs were 0.042 mg · L^-1, 0.115 mg · L^-1 and 0.019 mg · L^-1, respectively. According to the standard of fish acute toxicity, mebendazole was high-toxic at 20 ℃ and was less toxic at 15 ℃ and 25 ℃. Deltamethrin and copper sulphate were high-toxic and middle-toxic at three water temperatures. The results reveal that temperature affected SCs of different drugs to A.sapidissima greatly. Thus, dose of fishery drugs should be adjusted cautiously according to different water temperatures.