操作胁迫对褐鳟血液理化及养殖水体中皮质醇的影响

Effects of Handling Stress Out of Water on Blood Parameters and Tank Water Cortisol in Brown Trout Salmo trutta

摘要: 在室内养殖系统中，对褐鳟进行离水操作30 s，1 h后测定褐鳟血糖浓度、血细胞容积、血浆皮质醇含量、肠壁通透性等，同时分时间段来测定养殖水体中皮质醇含量，探讨其作为褐鳟无创性应激指标的可能性。结果显示：褐鳟离水操作1 h后，其血糖浓度和血细胞容积与对照组相比无显著性变化，但血液皮质醇含量显著升高(74.83 ± 23.1 ng/mL vs. 142.93 ± 48.2 ng/mL, P < 0.05)。操作胁迫后褐鳟肠壁电位差(Potential Difference, PD)发生明显的变化，应激组鱼肠壁PD值显著低于对照鱼，说明鱼类应激反应使肠道黏膜侧和浆膜侧的主动转运减少。另外，通过测定发现养殖水体中皮质醇在褐鳟操作胁迫后持续上升，1 h达到最高，含量为0.009 ng/(g * h)，再次验证了养殖水体皮质醇作为褐鳟无创性应激指标的可能性，为提高养殖鱼类福利奠定了理论基础。

Abstract: Brown trout was carried out of water for 30 s in the indoor aquaculture system, and the blood glucose concentration, blood cell volume, plasma cortisol content and intestinal permeability were measured after 1 h. Meanwhile, the content of cortisol in the tank water was measured to discuss the possibility of water cortisol as the non-invasive stress index of brown trout. The re-sults showed that there were no significantly differences in blood glucose concentration and blood cell between the stressed and control group, while the content of plasma cortisol increased significantly (74.83 + 23.1 ng/mL vs. 142.93 + 48.2 ng/mL, P < 0.05) in stressed fish. The intestinal wall potential difference (PD) was significantly lower, indicating that the stress could reduce the active transport between intestinal mucosa side and serous side. In addition, it was found that the tank water cortisol was rising and come to 0.009 ng/ (g * h) after 1 h. The study suggested that it is possible to consider tank water cortisol as the non-invasive stress index of brown trout in aquaculture system, which laid a theoretical foundation for improving fish welfare.