Keywords: 
• pyraclostrobin /
• zebrafish /
• embryo /
• larvae /
• toxicity

Abstract: In order to assess the toxicity effects of pyraclostrobin to different life stages of fish, zebrafish (Brachydanio rerio) during embryo, larvae (hatched 3 days and hatched 12 days) and adult stages were selected to evaluate the acute toxicity as well as the development effects. The results showed that the 96 h-LC₅₀ values of pyraclostrobin to embryos, larvae (hatched 3 days), larvae (hatched 12 days) and adult of zebrafish were 0.0578(0.0540-0.0631), 0.0299(0.0282-0.0320), 0.0330(0.0310-0.0350) and 0.0756(0.0692-0.0862) mg·L^-1, respectively. The toxicity of pyraclostrobin to four different life stages of zebrafish as follows: larvae (hatched 3 days) > larvae (hatched 12 days) > embryo > adult fish. Compared with control groups, the spontaneous movements of 24 hpf embryos was significantly decreased by pyraclostrobin at concentration of 0.101 mg·L^-1. The heart beat of the embryos was significantly inhibited by 0.0609, 0.0777 and 0.101 mg·L^-1 pyraclostrobin at 48 hpf. Furthermore, 0.0609 and 0.0777 mg·L^-1 pyraclostrobin could significantly reduce body length of hatched larvae at 96 hpf. At the higher test concentrations, pyraclostrobin induced a suite of morphological abnormalities during the embryonic development, including pericardial edema, yolk sac edema and melanin reduction. However, pyraclostrobin did not induce apparent abnormities in larvae (hatched 3 days).