| In studying the joint toxicity of ethynylestradiol（EE2） and dibutyl phthalate（DBP） on the embryonic development of zebrafish, a 1∶1 ratio of EE2 and DBP was used. The primary research objective was to observe and compare the embryonic development, mortality, and hatchability behaviors of zebrafish embryos within a 96-hour time frame. Furthermore, using a trifold technique of additive index method, toxic unit analytical method, and toxicity unit graphic method, we analyzed the effects of EE2 and DBP on zebrafish in varying doses and under varying time conditions. The results illustrated that zebrafish embryos were sensitive to the toxic effects of EE2 and DBP, thus demonstrating a significant sensitivity to both concentration of the dose and accumulation of time. The embryos begun to develop defects as well（e.g., tail defects, edema, spine curvature, delayed hatching）. The toxicity of DBP was higher than that of EE2; the 96-hour median lethal concentration（LC50） of DBP and EE2 were 2.219 mg·L-1 and 3.975 mg·L-1, respectively. The joint-dose of DBP and EE2 produced an antagonistic effect on mortality of zebrafish at 80 hours but a synergistic effect at 96 hours. |
