Effect of high temperature and hypoxia on median lethal time and physiological function in sea cucumber Apostichopus japonicus of two sizes

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 高温和低氧胁迫对两种规格刺参半致死时间及生理机能的影响 DOI: 作者: 作者单位: 1. 中国海洋大学, 海水养殖教育部重点实验室, 山东 青岛 266003;2. 青岛海洋科学与技术国家实验室, 海洋渔业科学与食物产出过程功能实验室, 山东 青岛 266071 作者简介: 周晓梦(1992-),女,硕士研究生,专业方向为渔业资源.E-mail:447189590@qq.com 通讯作者: 中图分类号: S96 基金项目: 国家海洋公益性行业科研专项（201405010）；青岛海洋科学与技术国家实验室鳌山科技创新计划项目（2015ASKJ02）. Effect of high temperature and hypoxia on median lethal time and physiological function in sea cucumber Apostichopus japonicus of two sizes Author: Affiliation: 1. Key Laboratory of Mariculture, Ministry of Education;Ocean University of China, Qingdao 266003, China;2. Functional Laboratory of Marine Fisheries Science and Food Production Process;Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:通过实验生态学方法，针对2种规格的刺参（）（大：28.00~36.00 g；小：9.00~13.00 g），测定温度为（25.0±0.5）℃溶解氧（DO）水平为（1.0±0.1）mg/L条件下刺参的半致死时间（LT50）；比较分析了DO水平分别为（1.0±0.1）mg/L、（3.0±0.1）mg/L及6.5 mg/L（正常DO含量）条件下2种规格刺参的昼夜代谢水平；监测了DO水平分别为（1.0±0.1）mg/L和（3.0±0.1）mg/L时低氧胁迫24 h及复氧72 h期间，2种规格刺参体腔液和呼吸树中的谷胱甘肽（GSH）含量、总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性及体腔液中皮质醇水平的变化，以探究夏季高温期（25.0±0.5）℃低氧胁迫对不同规格刺参半致死时间及生理机能的影响。结果显示：当DO浓度为1 mg/L时，大规格刺参半致死时间（LT50）为33.37 h，小规格刺参为28.84 h，2种规格刺参的代谢水平显著低于常氧对照组，夜间代谢强度高于白天，且小规格刺参的代谢强度高于大规格刺参。1 mg/L低氧胁迫期间，大规格刺参体腔液及2种规格刺参呼吸树中上述4种抗氧化指标的变化趋势大致相同，与对照组相比，随着低氧暴露时间的延长，GSH含量下降，SOD和T-AOC活力降低，CAT活力升高；然而胁迫结束时其GSH含量、CAT、SOD和T-AOC活力均与对照组无显著差异（>0.05）。解除胁迫复氧72 h后，2种规格刺参体腔液的4种抗氧化指标均恢复到对照组水平；而呼吸树的这4种指标则未完全恢复。3 mg/L低氧胁迫期间，2种规格刺参体腔液和呼吸树的GSH含量、CAT、SOD和T-AOC活力的变化趋势与1 mg/L组大体一致，复氧72 h后体腔液的各项指标恢复到对照组水平；除T-AOC，呼吸树的其余3种指标亦完全恢复。低氧胁迫后小规格刺参的恢复能力高于大规格刺参。在DO为1 mg/L和3 mg/L条件下，胁迫结束时2种规格刺参体腔液中的皮质醇含量显著高于对照组（<0.05），且大规格刺参皮质醇含量高于小规格，复氧后二者均恢复到对照水平。结果表明，低氧胁迫持续时间不超过其半致死时间（本研究以24 h为例），刺参可通过自身调节减轻机体的氧化损伤；一旦超出半致死时间，将产生不可逆损伤，最终导致死亡。 Abstract:An experimental ecological method was used to determinate the effects of hypoxia on the median lethal time (LT50) and physiological function of two sizes of sea cucumber (large-size:with a body weight ranging from 28.00 g to 36.00 g; small-size:with a body weight ranging from 9.00 g to 13.00 g) at high temperature (25℃). The LT50 in the two sizes of sea cucumber at a dissolved oxygen (DO) concentration of 1 mg/L were investigated. The diurnal metabolism in the two sizes of sea cucumber at DO concentrations of 1, 3, and 6.5 mg/L (normoxia) were estimated. The glutathione (GSH) content and activities of superoxide dismutase (SOD), catalase (CAT), and total antioxidant capability (T-AOC) in the coelomic fluid and respiratory tree, as well as the cortisol level in the coelomic fluid at 24 h hypoxia stress (the DO concentrations of 1 mg/L and 3 mg/L) and 72 h reoxygenation of the two sizes of sea cucumber were also measured. The results showed that, at first, at the DO concentration of 1 mg/L, the LT50 for the large and small-size sea cucumber was 33.37 h and 28.84 h, respectively. The metabolism in the two sizes of sea cucumber was significantly lower than that in the normoxia condition (hereafter control), the overnight metabolic intensity was higher than during the daytime, and metabolic intensity in the small-size sea cucumber was higher than in the large-size one. Secondly, during the 1 mg/L hypoxia stress, the variations of the four antioxidant indices in the coelomic fluid in the large-size sea cucumber and those in the respiratory tree in both sizes of sea cucumber were similar:compared with the control group, the hypoxia exposure decreased the content of GSH and the activity of SOD and T-AOC, but increased the activity of CAT. However, at the end of the hypoxia stress, the content of GSH and the activity of SOD, CAT, and T-AOC showed no significant difference from the control group. After 72 h of reoxygenation, the above four antioxidant indexes of the coelomic fluid in the two size groups of sea cucumber recovered to the level of the control group but the four antioxidant indexes of the respiratory tree did not. During the 3 mg/L hypoxia, the variation trend of the four antioxidant indexes in the coelomic fluid and respiratory tree of sea cucumber was consistent with those in the 1 mg/L group. After 72 h of reoxygenation, the above four antioxidant indexes of the coelomic fluid in sea cucumber recovered to the level of the control group. Except for T-AOC, the other three indices of the respiratory tree also recovered. The recovery ability of the small-size sea cucumber was higher than that of the large one after hypoxia stress. Thirdly, at the DO concentrations of 1 mg/L and 3 mg/L, the content of cortisol in the coelomic fluid of both sizes of sea cucumber was significantly higher than the control group at the end of the stress (<0.05). The level of cortisol in the coelomic fluid of the large-size sea cucumber was higher than in the small one but both recovered to the control level after reoxygenation. The results showed that if the hypoxia duration is less than the LT50(24 h, for example, in this paper), sea cucumber can alleviate the oxidative damage. However, if the time under hypoxia exceeds the threshold value, sea cucumbers will suffer irreversible damage and die. 参考文献 相似文献 引证文献