Pesticide Toxicity in the Larvae of Japanese Flounder, Paralichthys olivaceus

Acute toxicity of diazinon and MEP was assessed for larvae and juveniles of Japanese flounder. The LC₅₀ values obtained for diazinon ranged from 0.86 to 2.65 ppm, 0.50 to 1.73 ppm and 0.20 to 0.82 ppm at 24, 48 and 96 hours, respectively. MEP showed similar toxicity to those fish for which the LC₅₀ values were 0.74 to 1.89 (24 h), 0.50 to 1.24 (48 h), and 0. 26 to 0.86 (96 h). Pre-metamorphosis larvae were generally more susceptible to either pesticide.