Developmental Toxic Effects of Phosmet on Zebrafish (Danio rerio) Embryos

Phosmet, an organophosphate pesticide, has been widely applied to plants and animals. As the adverse effects of phosmet on the aquatic vertebrates are not fully understood, the present study was aimed to evaluate the developmental toxicity of phosmet u sing zebrafish (ZF) (Danio rerio) embryos. The ZF embryos were treated with 2.96, 4.44, 6.66, 10, and 15 mg/L of phosmet. Consequently, the embryo mortalities and developmental deformities were recorded at 24, 48, 72, and 96 hours post fertilization (hpf). The results showed that the effects of phosmet on ZF embryos were time- and dose-dependent. The median lethal concentration (LC50) of phosmet at 96 h was 7.95 ± 0.30 mg/L. The results of developmental toxicity showed that the phosmet induced a series of deformities in somites, tails, spines, yolk-sacs, hearts and swim bladders of ZF embryos and larvae. Among the deformities, the heart- and growth-related deformities were the most significant. Further, the phosmet-treated ZF displayed an abnormal touch-evoked response and swimming, suggesting potential neurodevelopmental toxicity of phosmet. The median effective concentration (EC50) of phosmet at 96 h was 4.38 ± 0.18 mg/L and the 96 h teratogenic index (TI) value was 1.7. Overall, these results indicate that phosmet is a teratogen and severely affects the growth of ZF in the earlier developmental stages. KCI Citation Count: 0