海水养殖与气象Ⅰ——石斑鱼低温寒害指标试验研究

Mariculture and MeteorologyⅠ——Study on Chilling Injury Index of Epinephelus coioides

本研究可揭示不同大小石斑鱼抗寒性差异及其机体应激反应,探索斜带石斑鱼生存的临界温度,为石斑鱼养殖选择合理放养周期、寒害风险评估、制定防寒减灾决策提供科学依据。试验以5、200、600 g/尾斜带石斑鱼为研究对象,通过逐渐降低水温并记录不同水温下的存活情况,并测定其超氧化物歧化酶含量。结果表明：（1）石斑鱼小鱼轻度寒害指标为水温11℃,持续1天,中度寒害指标为水温10℃,持续时间1～2天,重度寒害指标为10℃,持续3天。中鱼的轻度寒害指标为14℃,持续1天,中度寒害指标12℃,持续1天,重度寒害指标为11℃,持续1天。大鱼的轻度寒害指标为15℃,持续1～2天,中度的寒害指标为15℃,持续3天,重度寒害指标为14℃,持续1天；（2）小石斑鱼在低温刺激下,肝和鳃SOD显著提高,中鱼鳃SOD显著下降,而肝SOD先升高后下降,大鱼肝SOD和鳃SOD都先升后降,但整体活性水平相对稳定。

Study on chilling injury tolerance for different size of Epinephelus coioides and their stress response is important for exploring lethal temperatures, choosing suitable culture cycle and taking disaster preventing and mitigating measures. Based on three different sizes of Epinephelus coioides, young fish（5 g）, medium fish（200 g） and adult fish（600 g）, the experiment studied survival rate and activities of Superoxide Dismutase（SOD） on different low temperature stress. The results showed as follows：（1） The sever chilling injury index of young fish was 10℃ with 50% mortality rate in three days and the medium fish was 11℃ within duration of 1 day while the adult fish was 14℃. This indicated the ability of anti-stress of low temperature declined as the fish grew up.（2） The activities of SOD in gill and liver of young fish rose significantly as temperature decreased. For medium fish, the activities of SOD in gill dropped down. However, SOD in liver experienced an up-to-down changing process, which was the same as adult fish in both gill and liver.