Polycyclic aromatic hydrocarbons (PAHs) are typical pollutants and may be alkylated and oxygenated to form alkyl-PAHs and oxygenated-PAHs (oxy-PAHs), respectively. Takifugu obscurus is an important anadromous fish species and displays a high risk of being exposed to PAHs-contaminated areas. In the present study, the effects of acute exposure to 44.29 µg L⁻¹ 9,10-phenanthrenequione (9,10-PQ), retene and phenanthrene (Phe) on T. obscurus liver histology, antioxidant enzymes and immune indices were compared. After exposure to these three compounds, histological sections showed damages of hepatocyte, and the activities of alanine and aspartate aminotransferase increased in plasma, indicating direct hepatic toxicity. Hepatic malondialdehyde (MDA) content increased, but superoxide dismutase (SOD) and catalase (CAT) activities decreased in response to treatments with Phe, retene and 9,10-PQ. These results revealed peroxidative effects on T. obscurus hepatocytes. In addition, total immunoglobulin content and lysozyme activity in plasma increased in treatments with Phe, retene and 9,10-PQ, which might be resulted from the damaged liver cells and the subsequently hepatic inflammation. Besides, the changes were more severe in treatment with 9,10-PQ than those with Phe and retene, demonstrating higher toxicity of 9,10-PQ than the other two compounds. Overall, the present study posed a high environmental risk of PAH derivatives to aquatic ecosystems.

多环芳烃（PAH）是典型的污染物，可以被烷基化和氧合以分别形成烷基PAHs和氧合PAHs（oxy-PAHs）。暗纹（Takifugu obscurus）是重要的无鳍鱼类，暴露于多环芳烃（PAHs）污染地区的风险很高。在本研究中，急性暴露于44.29 µg L ^-1的9,10-菲基喹啉（9,10-PQ），维生素A和菲（Phe）对暗纹T.比较肝脏组织学，抗氧化酶和免疫指标。暴露于这三种化合物后，组织学切片显示肝细胞受损，血浆中丙氨酸和天冬氨酸转氨酶的活性增加，表明直接肝毒性。肝丙二醛（MDA）含量增加，但超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性下降，响应苯丙氨酸，视黄酮和9,10-PQ处理。这些结果揭示了对暗纹T.的过氧化作用。肝细胞。此外，用苯丙氨酸，视黄醛和9,10-PQ处理的血浆中总免疫球蛋白含量和溶菌酶活性增加，这可能是由于受损的肝细胞和随后的肝炎引起的。此外，用9,10-PQ处理的变化比用Phe和视黄醛处理的变化更严重，表明9,10-PQ的毒性高于其他两种化合物。总体而言，本研究对水生生态系统造成了PAH衍生物的高环境风险。