In recent years, the need for the development of alternative test methods for the conventional acute fish toxicity test (AFT) with adult fish has often been discussed. In addition, concerns have been raised on the potential risks related with environmentally realistic pesticide mixtures since risk evaluations have traditionally been based on individual pesticides. The insecticide/acaricide abamectin and the fungicide difenoconazole are the main pesticides that are intensively used in Brazilian strawberry crop and are hence likely to occur simultaneously in edge-of-field waterbodies. The aim of the present study was therefore to evaluate the lethal and sublethal toxicity of single and mixture exposures of these pesticides to zebrafish early life stages (embryos and juveniles). By comparing the derived toxicity data of the individual compounds with that previously determined for zebrafish adults, the order of life stage sensitivity was juvenile > adult > embryo. The pesticide mixture revealed a dose-level dependent deviation of the independent action model, with antagonism at low dose levels and synergism at high dose levels. Sublethal parameters (especially those related with locomotion) were considerably more sensitive than lethality. Subsequently, the inclusion of sublethal parameters may greatly improve the sensitivity of FET tests and hence its suitability as a substitution of adult fish testing in risk assessment evaluations.

近年来，经常讨论开发成年鱼的常规急性鱼毒性试验（AFT）的替代试验方法的需求。另外，由于风险评估传统上是基于单独的农药，因此引起了与环境现实的农药混合物相关的潜在风险的担忧。杀虫剂/杀螨剂阿维菌素和杀真菌剂苯芬康唑是在巴西草莓作物中大量使用的主要农药，因此很可能同时在田间水体中发生。因此，本研究的目的是评估这些农药对斑马鱼生命早期阶段（胚胎和幼虫）的单一和混合接触所致的致死和亚致死毒性。通过将各个化合物的衍生毒性数据与先前对斑马鱼成年动物确定的毒性数据进行比较，生命阶段敏感性的顺序为：少年>成年>胚胎。农药混合物显示了独立作用模型的剂量水平依赖性偏差，低剂量水平有拮抗作用，高剂量水平有协同作用。亚致死参数（尤其是与运动相关的参数）比致死性更为敏感。随后，包含亚致死参数可以大大提高FET测试的敏感性，因此可以替代风险评估评估中的成鱼测试。农药混合物显示了独立作用模型的剂量水平依赖性偏差，低剂量水平有拮抗作用，高剂量水平有协同作用。亚致死参数（尤其是与运动相关的参数）比致死性更为敏感。随后，包含亚致死参数可以大大提高FET测试的敏感性，因此可以替代风险评估评估中的成鱼测试。农药混合物显示了独立作用模型的剂量水平依赖性偏差，低剂量水平有拮抗作用，高剂量水平有协同作用。亚致死参数（尤其是与运动相关的参数）比致死性更为敏感。随后，包含亚致死参数可以大大提高FET测试的敏感性，因此可以替代风险评估评估中的成鱼测试。