Azoxystrobin (AZX) is a broad-spectrum systemic fungicide massively used worldwide. Its mode of action consists in the inhibition of mitochondrial respiration decreasing the synthesis of ATP and leading to oxidative stress in the target fungus. However, whether this effect occurs in non target organisms has been scarcely studied. The objectives of this work were (1) to evaluate biomarkers of oxidative stress, hematological, physiological and of genotoxicity in the native cichlid fish Australoheros facetus exposed to environmentally relevant concentrations of AZX and (2) to compare these biomarkers in different developmental stages using juvenile and adult fish (n = 6) exposed during 48 h. The exposure concentrations were 0 (negative control, C (−)), 0.05, 0.5, 5 and 50 μg/L AZX of the commercial formulation AMISTAR®. Blood was drawn to evaluate hematology, and DNA damage through the comet assay (CA) and micronucleus test (MN). Genotoxicity was observed by mean of both biomarkers in juvenile and adult fish at 50 μg/L AZX. Samples of liver and gills were used to determine antioxidant enzymes activity, hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) contents. In juvenile fish inhibition of superoxide dismutase (SOD) was observed in liver at 0.05, 5 and 50 μg/L AZX and in gills at 5 and 50 μg/L AZX. Glutathione- S- transferases (GST) activity increased in gills at all AZX concentrations tested. In adult fish, increase of hepatic catalase (CAT) activity at 0.5 and 50 μg/L AZX and MDA content at 50 μg/L AZX were observed. In gills only H₂O₂ content showed changes at 50 μg/L AZX. The sensitivity showed by gills constitutes the first report about AZX toxicity in this organ. All these negative effects were observed in the range of realistic AZX concentrations, which warns of the possible consequences that it may have on the health of aquatic biota. Differences between juvenile and adult fish demonstrate the relevance of considering the developmental stage on the evaluation of biomarkers.

Azoxystrobin（AZX）是一种广谱的系统性杀菌剂，已在世界范围内广泛使用。其作用方式在于抑制线粒体呼吸，从而降低了ATP的合成并导致了目标真菌的氧化应激。但是，几乎没有研究这种作用是否在非靶标生物中发生。这项工作的目标是（1）评估天然丽鱼科鱼类澳大利亚丽鱼的氧化应激，血液学，生理学和遗传毒性的生物标记暴露于环境相关浓度的AZX和（2），以使用48小时内暴露的幼鱼和成年鱼（n = 6）比较不同发育阶段的这些生物标记。暴露浓度为商业配方AMISTAR？的0（阴性对照，C（-）），0.05、0.5、5和50μg/ L AZX。抽血以评估血液学，并通过彗星试验（CA）和微核试验（MN）评估DNA损伤。通过两种生物标志物在50μg/ L AZX的幼鱼和成年鱼中均观察到了基因毒性。使用肝和腮样品测定抗氧化酶活性，过氧化氢（H ₂ O ₂）和丙二醛（MDA）含量。在幼鱼中，在肝脏中0.05、5和50μg/ L AZX和在g中在5和50μg/ L AZX观察到超氧化物歧化酶（SOD）的抑制作用。在所有测试的AZX浓度下，g中的谷胱甘肽-S-转移酶（GST）活性均增加。在成年鱼中，观察到0.5和50μg/ L AZX时肝过氧化氢酶（CAT）活性增加，以及50μg/ L AZX时MDA含量增加。在g中只有H ₂ O ₂含量在AZX 50μg/ L处显示变化。g表现出的敏感性是有关该器官中AZX毒性的第一个报道。在实际的AZX浓度范围内观察到了所有这些负面影响，并警告了其可能对水生生物的健康造成的后果。幼鱼和成年鱼之间的差异表明，在生物标记物的评估中考虑发育阶段的相关性。