西沙群岛东岛轮藻的发现及其意义  

The discovery of Charophytes in Dongdao Island of Xisha Ialanda and its significance

作　　者：纪振强 葛晨东[1,2,3] 邹欣庆 Ji Zhenqiang;Ge Chendong;Zou Xinqing(The Key Laboratory of Coast&Island Development of Ministry of Education,Nanjing University,Nanjing 210023,Jiangsu;Collaborative Innovation Center of South China Sea Studies,Nanjing University,Nanjing 210023,Jiangsu;School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210023,Jiangsu)

机构地区：[1]南京大学海岸与海岛开发教育部重点实验室,江苏南京210023 [2]南京大学中国南海研究协同创新中心,江苏南京210023 [3]南京大学地理与海洋科学学院,江苏南京210023

出　　处：《第四纪研究》2019年第6期1428-1432,共5页Quaternary Sciences

基　　金：中国科学院学部咨询评议项目(批准号:2016ZWH005A-005)资助。

摘　　要：东岛是西沙群岛第二大岛,东岛"牛塘"是西沙群岛中少见的淡水型湖泊,在牛塘的表层沉积物中发现了大量现生轮藻藏卵器,经鉴定为Lamprothamnium(丽枝轮藻属)。其藏卵器为长球形或亚长球形,最大长度(LPA)为560~780μm,最大宽度(LED)为360~500μm,等轴率(ISI)为156~194。前人对东岛牛塘沉积物钻孔的研究中均没有轮藻的相关报道,此次发现的轮藻是南海诸岛轮藻的首次发现,轮藻的发现意味着该地的淡水生态系统发育到更加稳定的新阶段,对西沙群岛淡水生态系统的研究有重要意义,也为南海珊瑚岛礁淡水生态系统的管理与保护提供科学依据。Coral reefs are widely distributed in the South China Sea.The development and construction of coral reefs in the South China Sea,especially the construction of artificial reefs in the South China Sea,have attracted wide attention in recent years.In March 2018,we collected 5 surface samples in Dongdao Island,Xisha Islands.After microscopic observation,charophyte oogoniums were found in the surface sediments of freshwater lakes on the Dongdao Island,Xisha Islands.Charophytes were found in Xisha Islands for the first time.This discovery means that the freshwater ecosystem here has entered a more stable new stage.Upon appraisal,these oogoniums belong to Lamprothamnium,most of the oogoniums are prolate,the others are subprolate.The largest polar axis(LPA)is 560~780μm,the largest equatorial diameter(LED)is 360~500μm,the isopolarity index(ISI)is 156~194.These features accord with Lamprothamnium oogonium.Living charophytes were found in Xisha Islands for the first time,which means the freshwater ecosystem in Dongdao Island developed to a more stable stage.This discovery is important for the study of freshwater ecosystem in Xisha Islands,which also provide scientific basis for the management and protection of the freshwater ecosystem of the coral reefs in the South China Sea,especially for the construction of artificial reefs in the South China Sea.

关 键 词：丽枝轮藻 淡水生态系统 西沙群岛东岛 

分 类 号：Q949.218.3[生物学—植物学] Q913.2[天文地球—古生物学与地层学]