本研究采用动态温升实验方法,以矛尾鰕虎鱼(Chaeturichthys stigmatias)、许氏平鲉(Sebastes schlegelί)、口虾蛄(Oratosquilla oratoria)和日本蟳(Charybdis japonica)为研究对象,研究了5个基础水温(8.0、14.0、18.0、24.0和28.0℃)和9个温升速率(0.5、1.0、2.0、3.0、4.0、 6.0、9.0、 12.0和15.0℃/h)下4种海洋生物的半致死温度(Lethal temperature of 50%,LT_(50))。结果显示,基础水温和温升速率均能显著(P<0.05)影响实验生物的LT_(50)。特定温升速率下实验生物LT_(50)与基础水温呈正相关,即各个实验生物的LT_(50)随着基础水温的升高而升高。温升速率对实验生物LT_(50)的影响因基础水温和物种而异。本研究在动态温升实验中结合使用不同基础水温和多个温升速率,构建了海洋生物重要的热耐受性评价指标LT_(50),可广泛应用于海洋生物的热耐受性评价。
英文摘要:
In recent years, global warming and the release of hot wastewater from nuclear power plants have caused the temperature of sea water to rise,leading to severe thermal pollution of the oceans. Marine ecosystems and the survival of marine life face huge challenges from ocean warming. Research on the thermal tolerance of marine organisms will help us to understand the heat tolerance of different marine species and determine how to control thermal discharge from nuclear power plants. This study investigated the heat tolerance of four marine species (Chaeturichthys stigmatias, Sebastes schlegeli, Oratosquilla oratoria, and Charybdis japonic a) in Liaodong Bay using a dynamic temperature-rising test. The lethal temperature of 50% (LT_(50)) was assessed at five acclimation temperatures (8.0℃,14.0℃18.0 ℃,24.0℃,28.0℃) and nine temperature-rising rates (0.5, 1.0,2.0,3.0,4.0,6.0,9.0,12.0, 15.0℃/h) to evaluate heat tolerance. The results showed that both the acclimation temperature and temperature-rising rate significantly affected the LT_(50) value of the experimental animals (P<0.05). The LT_(50) values were significantly positively correlated with the acclimation temperature (P<0.05), while the effects of the temperature-rising rate varied with acclimation temperature in a species-dependent manner. In this study, the dynamic temperature-rising test included a higher number of acclimation temperatures and temperature-rising rates than used in previous studies, and we established the LT_(50) value as an important indicator for evaluating the heat tolerance of marine species. These results suggest that as an evaluated index, LT_(50) comprehensively reflects the heat tolerance of experimental species, which is of scientific and ecological significance and could be widely used in the assessment of heat tolerance.