长棘海星胃含物和幽门肠δ^(13)C对其食源的指示意义  

Feeding Habits of Acanthaster spp.,as Indicated by the Carbon Stable Isotope Values of Food in Their Gastric Contents and Pyloric Gut

作　　者：马蕾 许慎栋 余克服 黄学勇 陈飚 韦芬 Ma Lei;Xu Shendong;Yu Kefu;Huang Xueyong;Chen Biao;Wei Fen(School of Marine Sciences,Guangxi University,Guangxi Laboratory on the Study of Coral Reefs in the South China Sea,Nanning 530004,China;Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China)

机构地区：[1]广西大学海洋学院,广西南海珊瑚礁研究重点实验室,南宁530004 [2]中国科学院烟台海岸带研究所,中国科学院海岸带环境过程与生态修复重点实验室,山东烟台264003

出　　处：《热带地理》2024年第10期1847-1853,共7页Tropical Geography

基　　金：国家自然科学基金项目(42090041、42030502)。

摘　　要：长棘海星(Acanthaster spp.)是珊瑚的天敌,其周期性暴发是导致珊瑚礁退化的最重要原因之一。了解长棘海星的食物来源或有可能为应对长棘海星暴发提供科学依据,但迄今关于长棘海星食物来源的认识基本来自于野外,即认为长棘海星以珊瑚组织为食,极少关于其同位素方面的信息。文章以2020年3月在南海西沙群岛采集的不同体长的长棘海星为材料,首次测定其胃含物稳定碳、氮同位素值(δ^(13)C、δ^(15)N)及幽门肠碳稳定同位素值,以探讨其食物来源。根据体长将所分析的长棘海星分为亚成体(体长10~200 mm)、成体(体长200~350 mm)、高龄成体(体长>350 mm)3个年龄段。结果显示:1)胃含物和幽门肠的δ^(13)C值范围分别为-15.03‰~-13.00‰和-15.21‰~-13.24‰,二者的变化趋势一致,表明其对食源的指示具有一致性;2)随着体长和年龄的增长,长棘海星的胃含物和幽门肠的碳同位素值均呈下降趋势,而胃含物的氮同位素值呈上升趋势,表明长棘海星的食源随年龄增加发生改变,且其营养级也呈增高趋势,在亚成体阶段的食物以相对低营养级的食物为食,而在成体后以相对高营养级的食物为食。The periodic outbreaks of Acanthaster spp.which are predators of coral,are important reasons for the degradation of coral reefs.Information on the food sources of Acanthaster spp.Would be useful for suppressing outbreaks of the species.Although field observations on the feeding habits of Acanthaster spp.,suggest that they feed mainly on corals,no isotopic evidence has been provided to support this.Therefore,this study was conducted to explore the food sources of Acanthaster spp.from the perspective of stable carbon(δ^(13)C)and nitrogen isotopes(δ^(15)N)by analyzing the consistency of theδ^(13)C values of food in the gastric contents and pyloric gut as well as the significance of theirδ^(13)C andδ^(15)N values,with the goal being to attain new information for comprehensively understanding or controlling outbreaks of these predators.In March 2020,various Acanthaster spp.were collected from the reef slope of coral reefs in the Xisha Islands,at a water depth of less than 10 m.The sampled individuals were immediately placed in a-20°C refrigerator for transport to the laboratory,after which they were stored in-80°C freezer.The gastric contents and pyloric gut were extracted for measurement ofδ^(13)C andδ^(15)N values to investigate the feeding habits of Acanthaster spp.for the first time.The collected individuals were divided into three age groups:sub-adult(10~200 mm diameter),adult(200~350 mm),and senile-adult(>350 mm).Theδ^(13)C values of the gastric contents and pyloric gut were-15.03‰~-13.00‰and-15.21‰~-13.24‰,respectively.The average change inδ^(13)C values(△δ^(13)C)between the gastric contents and pyloric gut were 0.17‰,0.20‰,and 0.04‰for the sub-adult,adult,and senile-adult groups,respectively.The results showed the following:(1)Theδ^(13)C values of the gastric contents correlated positively with those of the pyloric gut for Acanthaster spp.of different diameters.There were no significant differences in averageδ^(13)C values between the gastric contents and pyloric gut.The same corr

关 键 词：碳稳定同位素 氮稳定同位素 食性 胃含物 幽门肠 长棘海星 

分 类 号：Q958.8[生物学—动物学]