【摘要】 本研究旨在探讨绿鳍马面鲀对不同温度的生理响应机制。挑选规格相近的健康幼鱼，分为对照组（20℃）和试验组（25、28、31℃）,测定了不同温度条件下绿鳍马面鲀的存活情况和总抗氧化能力、超氧化物歧化酶、过氧化氢酶、碱性磷酸酶、酸性磷酸酶等生化指标及热休克蛋白90（HSP90）基因表达情况。结果表明，绿鳍马面鲀幼鱼在24、48、72、96 h的半致死温度(LT₅₀)分别为31.7、31.5、31.2、31.1℃。与对照组相比，温度胁迫下，总抗氧化能力和4种酶活性均呈现先升后降的趋势，其中超氧化物歧化酶活性在28℃达到峰值，其他酶活性在25℃达到最高。HSP90基因表达在温度胁迫下先升后降，28℃时肝脏中表达量最高，较对照组提高21.74倍。基于短期胁迫数据，25～28℃是绿鳍马面鲀的最适宜温度区间，应避免长时间暴露于28℃以上环境。HSP90基因参与温度胁迫应答过程的生理调节，可作为绿鳍马面鲀应答高温胁迫的标志物。研究结果可为绿鳍马面鲀的健康养殖提供理论数据。更多还原

【Abstract】 In order to explore the physiological response mechanism of bluefin leatherjack Thamnaconus septentrionalis to different temperatures, juveniles bluefin leatherjack were kept in plastic buckets with a diameter of 60 cm and a capacity of 136 L at water temperature of 20 ℃（control group）, 25, 28, 31 ℃ or 33 ℃（to determine the survival rate） for determination of survival rate, activities of superoxide dismutase（SOD）, catalase（CAT）, alkaline phosphatase（AKP）, acid phosphatase（ACP） and heat shock protein 90（HSP90） gene expression. Results showed that the 24,48,72,96 h median lethal temperatures(LT₅₀) for juvenile bluefin leatherjack were 31.7, 31.5, 31.2, and 31.1 ℃, respectively. T-AOC and enzyme activities were shown to be an initial increase, then decline under thermal stress compared to the fish in control group, with SOD activity peak at 28 ℃, and the maximum levels at 25 ℃ for other enzymes. HSP90 gene expression was found to be upregulated and subsequently downregulated, with the maximal expression level in the liver at 28 ℃（21.6-fold higher than htat in the control）. The short-term stress revealed that the optimal temperature was ranged from 25 to 28 ℃ for bluefin leatherjack, with avoidance in prolonged exposure above 28 ℃. It was found that HSP90 played pivotal role in mediating physiological adaptations to thermal stress, suggesting its utility as a biomarker for evaluating heat stress responses in this species. The finding provides critical insights to support sustainable aquaculture practices for bluefin leatherjack.更多还原