摘要： 低氧是水产动物活体运输过程中的一个重要应激源，会影响水产品的运输成活率。文章旨在模拟并探究急性低氧应激对鲫鱼幼鱼（Carassius crassius）相关血液生化指标的影响。对鲫鱼进行24 h的急性低氧处理，溶氧水平为（0.61±0.23）mg/L，测定低氧应激0 h、3 h、6 h、12 h和24 h，共5个时间点的血液血红蛋白（Hb）、血液高铁血红蛋白（MetHb）、血清皮质醇（COR）、葡萄糖（GLU）、热休克蛋白70（Hsp70）含量和超氧化物歧化酶（SOD）活性的变化。结果显示：在低氧应激过程中，Hb含量呈现先降低后升高的变化趋势，12 h时显著低于0 h（P＜0.05），24 h时又恢复至应激前水平；MetHb、COR、GLU和Hsp70含量均呈现先升高后降低的变化趋势，且不同指标达到含量峰值的时间点略有差异；SOD活力随着低氧应激时间的延长有升高趋势，但是前后变化差异不显著（P>0.05）。研究表明，当水体溶氧低于0.6mg/L时，随着急性低氧应激时间的延长，会造成鲫鱼的部分血液生化指标发生显著性变化，预示着低氧应激对鲫鱼机体代谢功能产生了较大的影响，因此在鲫鱼运输过程中，为提高运输成活率，应避免低氧等不良环境条件的出现。

关键词: 鲫鱼, 低氧应激, 生化指标, 水产养殖

Abstract: As an important stress source, hypoxia can affect the survival rate of aquatic animals during transportation.  The aim of this study was to simulate and investigate the effects of acute hypoxic stress on blood biochemical indices of juvenile Carassius crassius. Carassius crassius were exposed to acute hypoxia for 24 hours at a dissolved oxygen level of (0.61±0.23) mg/L. The measured indicators include blood hemoglobin (Hb), methemoglobin (MetHb), serum cortisol (COR), glucose (GLU), heat shock protein 70 (Hsp70) content and superoxide dismutase (SOD) activity following 0, 3, 6, 12 and 24 h acute hypoxia stress. The results showed that in the process of hypoxic stress, the Hb content first decreased and then increased. At 12 h, it was significantly lower than 0 h (P<0.05), and it returned to the pre-stress level at 24 h. The contents of MetHb, COR, GLU and Hsp70 all showed a change trend of first increasing and then decreasing, and the time points of reaching the peak content of different indices were slightly different. SOD activity increased with the extension of stress time, but the difference was not significant. Studies show that when the dissolved oxygen in water is lower than 0.6 mg/L, with the extension of acute hypoxia time, some important blood biochemical indicators of Carassius crassius change significantly, which also indicates that hypoxia stress has a great impact on the metabolic functions of Carassius crassius. Therefore, in order to improve the survival rate of Carassius crassius, adverse environmental conditions such as hypoxia should be avoided during their transportation.

Key words:  Carassius crassius, hypoxia stress, biochemical indicators, aquaculture