Stress-induced by low water-dissolved oxygen (DO) negatively influences the overall fish performances. Hybrid yellow catfish (Pelteobagrus fulvidraco × P. vachelli) was subjected to 2 DO levels: 1.5 mg/L (hypoxia) and 6.5 mg/L (control-normoxia) during the period of the experiment. Blood and liver were sampled at 0.0-, 6.0-, 12.0-, 24.0-, 48.0-, and 96.0-h post-exposure. Results showed an increase in the hematological parameters including white blood cell (WBC), red blood cell (RBC), hemoglobin (HGB), and hematocrit percentage (HCT) during the first 24 h. HCT and HGB values were significantly increased after 6-h and 12-h post-exposure, whereas RBC and WBC counts were significantly decreased 48-h and 96-h post-exposure to hypoxia. Glucose, total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), and aspartate transaminase (AST) levels were increased in hypoxia group, meanwhile serum total protein (TP) showed balanced values in hypoxia group. Glucose values were significantly increased from 6 h, while the other parameters such ALT, AST, and TG were mostly significant increased at 96 h. Hypoxia-induced stress mostly affects the hepatic antioxidant and immune resistance functions, resulting in increments of cortisol levels, lysozyme, superoxide dismutase, and catalase enzyme activities. The concentration increments were observed in lactate dehydrogenase, hepatic TG, and complement C3 in hypoxia group. Liver TP and glycogen were reduced in the hypoxia group throughout the whole experiment time. Interestingly, all the indices (hemato-biochemical, oxidation, and immune resistance) were returned to normal after 96 h of recovery. Therefore, we conclude that DO below the normal threshold induced metabolic stress, immune suppression, and oxidative stress of the exposed fish. Although hybrid yellow catfish developed some strong adaptabilities to maintain oxygen provision, and generate energy from anaerobic sources to resist, these results contribute positively to the insights on different metabolic responses involved during hypoxic conditions.

由低水溶氧 (DO) 引起的压力会对鱼类的整体性能产生负面影响。杂交黄鲶（Pelteobagrus fulvidraco × P. vachelli) 在实验期间经受 2 种 DO 水平：1.5 毫克/升（缺氧）和 6.5 毫克/升（对照-常氧）。在暴露后 0.0、6.0、12.0、24.0、48.0 和 96.0 小时采集血液和肝脏样本。结果显示血液学参数在最初 24 小时内增加，包括白细胞 (WBC)、红细胞 (RBC)、血红蛋白 (HGB) 和血细胞比容百分比 (HCT)。HCT 和 HGB 值在暴露后 6 小时和 12 小时后显着增加，而 RBC 和 WBC 计数在暴露于缺氧后 48 小时和 96 小时显着下降。低氧组葡萄糖、总胆固醇（TC）、甘油三酯（TG）、丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）水平升高，同时低氧组血清总蛋白（TP）呈平衡值。葡萄糖值从 6 小时开始显着增加，而其他参数如 ALT、AST 和 TG 在 96 小时时大多显着增加。缺氧应激主要影响肝脏抗氧化和免疫抵抗功能，导致皮质醇水平、溶菌酶、超氧化物歧化酶和过氧化氢酶活性增加。低氧组乳酸脱氢酶、肝TG、补体C3浓度升高。在整个实验时间内，缺氧组的肝脏 TP 和糖原降低。有趣的是，所有指标（血液生化、氧化和免疫抵抗）在恢复 96 小时后恢复正常。因此，我们得出结论，低于正常阈值的 DO 会诱导暴露鱼的代谢应激、免疫抑制和氧化应激。