Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China.
Laboratory of Marine Biodiversity, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China.
Mar Environ Res. 2024 Nov;202:106758. doi: 10.1016/j.marenvres.2024.106758. Epub 2024 Sep 18.
Global warming may affect the health of marine species. However, the collected information on quantitative assessment of response in fish under elevated temperature is poorly defined. The present study aimed to quantitatively evaluate the effects of the hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) under elevated temperature (33 °C and 36 °C, ET1 and ET2) stress for 14 days. As endpoints, we examined changes in body growth, hemato-immunological parameters, liver oxidative stress markers, as well as changes of the stomach digestive enzymes. Compared to the control, the body weight was significantly decreased in ET2 group for 14 d exposure, and a remarkable change of differential leukocyte counts of the fish was observed in ET1 group at 3 d and in ET2 group at 14 d. The respiratory burst activity of the hybrid grouper leukocytes markedly decreased in the treatment groups after 14-d exposure. Overall, the antioxidant enzyme activities and transcriptional levels of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GSH-PX) were markedly inhibited in the liver for 3-d and 14-d exposure. The expression levels of nf-κb mRNA were significantly inhibited while the expression levels of atp2b1 mRNA were significantly induced after 14-d exposure. The activities of pepsin and lipase in the stomach were significantly reduced. In addition, an innovative hazard classification system (ET-HCS) was developed to quantitatively characterize the stress response of the fish following elevated temperature treatments. The stress level of ET2 group for 14-d exposure was ranked as level IV (high stress), and the other treatments were ranked as level II (low stress). Taken together, the findings of this study further extend our understanding of quantitative assessment of response in fish under high-temperature stress, which provides valuable information for improving countermeasures of mariculture industry.
全球变暖可能会影响海洋物种的健康。然而，目前对于高温下鱼类的反应的定量评估信息收集还很不完善。本研究旨在定量评估杂交石斑鱼（♀♀×♀♀）在高温（33°C 和 36°C，ET1 和 ET2）胁迫下 14 天的影响。作为终点，我们检测了鱼体生长、血液免疫参数、肝脏氧化应激标志物以及胃消化酶的变化。与对照组相比，ET2 组鱼体在 14 天暴露期的体重显著下降，ET1 组在 3 天和 ET2 组在 14 天的鱼白细胞分类计数发生显著变化。处理组的鱼白细胞呼吸爆发活性在 14 天暴露后明显降低。总的来说，抗氧化酶活性和超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽还原酶（GR）和谷胱甘肽过氧化物酶（GSH-PX）的转录水平在肝脏中均在 3 天和 14 天暴露后明显受到抑制。nf-κb mRNA 的表达水平在 14 天暴露后明显受到抑制，而 atp2b1 mRNA 的表达水平在 14 天暴露后明显升高。胃中胃蛋白酶和脂肪酶的活性显著降低。此外，还开发了一种创新的危害分类系统（ET-HCS），以定量描述鱼类在高温处理后的应激反应。ET2 组 14 天暴露的应激水平被评为 IV 级（高应激），其他处理组被评为 II 级（低应激）。总之，本研究的结果进一步扩展了我们对高温下鱼类反应的定量评估的理解，为改善海水养殖业的对策提供了有价值的信息。
