西沙群岛永乐四岛礁珊瑚礁区域鱼类物种组成及其差异

Fish species composition and differences in the coral reef area of the four islands in Yongle Atoll， Xisha Islands

摘要:

为探究西沙群岛永乐环礁4个岛礁（晋卿岛、羚羊礁、全富岛和银屿）的珊瑚礁鱼类种类特征，在2020至2023年期间，采用手钓、潜水捕捞和水下录像等方式对永乐四岛礁的珊瑚礁鱼类进行了调查。结合2020—2021年对银屿的调查研究资料，分析了永乐四岛礁珊瑚礁鱼类的种类组成、相似性和分类多样性等特征，并结合文献资料分析了永乐四岛礁珊瑚礁鱼类的食性、个体大小类型等特征。结果表明：（1）永乐四岛礁附近海域共发现260种珊瑚礁鱼类，隶属于2纲10目40科，其中鲈形目占绝对优势，隆头鱼科、雀鲷科和蝴蝶鱼科的种类数最多；（2）肉食性鱼类种类最为丰富，且以中小型鱼类为主，四岛礁大型鱼类的相似性系数显著低于中小型鱼类，说明四岛礁受到了不同程度的捕捞影响；（3）肉食性鱼类和大型鱼类在各岛礁所占比例均为晋卿岛>羚羊礁>全富岛>银屿，且平均分类差异指数（Δ⁺）为晋卿岛（54.94）>羚羊礁（53.30）>全富岛（52.63）>银屿（52.05），说明四岛礁珊瑚礁鱼类受到人类扰动的程度存在明显差异，受扰动程度表现为晋卿岛<羚羊礁<全富岛<银屿。研究对永乐四岛礁珊瑚礁鱼类组成的本底情况进行了解析，分析了人类扰动的影响，将为促进西沙群岛珊瑚礁鱼类资源的可持续发展提供理论依据，为珊瑚礁鱼类的保护与管理提供参考。

Abstract:

In order to investigate the species characteristics of coral reef fishes in the four islands in Yongle Atoll （Jinqing Island， Antelope Reef， Quanfu Island， and Yinyu Island） of Xisha Islands， this study was conducted on the coral reef fishes of the four islands from 2020 to 2023 by using hand-fishing， diving fishing， and underwater video methods. The species composition， similarity， and taxonomic diversity of coral reef fishes in the four islands were analyzed， incorporating data from the survey conducted on Yinyu Island from 2020 to 2021. Additionally， the feeding type and individual size of coral reef fishes in the four islands were examined in conjunction with relevant literature. The findings indicate that： （1） There are 260 species of coral reef fishes in the four islands of Yongle Atoll in recent years， belonging to 40 families in 10 orders of 2 classes. Perciformes emerges as the predominant order， with Labridae， Pomacentridae， and Chaetodontidae exhibiting the highest number of species. （2） The coral reef fishes from the four islands of Yongle Atoll were primarily composed of carnivorous fishes， with a prevalence of medium and small fishes and the coefficient of similarity was significantly lower for large fish than for small and medium fish， indicating that the four reefs have been affected by fishing to varying extents. （3） The proportions of carnivorous fish and large fish displayed the following order： Jinqing Island > Antelope Reef > Quanfu Island > Yinyu Island， and the average classification difference index （Δ⁺） followed the sequence： Jinqing Island （54.94） > Antelope Reef （53.30） > Quanfu Island （52.63） > Yinyu Island （52.05）， which suggested a significant difference in the degree of human disturbance levels among four islands， with the disturbance ranking as Jinqing Island < Antelope Reef < Quanfu Island < Yinyu Island. The study conducted an in-depth analysis of the coral reef fish composition at the four islands in Yongle Atoll， analyzed the influence of human disturbance， which will offer a theoretical basis for promoting the sustainable development of coral reef fish resources in the Xisha Islands and provide references for the conservation and management of coral reef fish.