基于形态学和宏条形码技术的南海西沙群岛浮游动物多样性的比较分析

西沙群岛是我国南海陆地面积最大的群岛，海域广阔，拥有重要的战略地位与丰富的海洋资源。为了解该海域浮游动物组成与分布特征，本研究于2019年5月在西沙群岛14个岛礁站位开展多学科综合调查，并采用形态学方法和基于18S V9测序的宏条形码技术对浮游动物样本组成进行鉴定。结果显示，此次西沙调查站位浮游动物样本的主要种类包括桡足类、软甲纲和箭虫纲，这3个类别的物种在两种鉴定方法中均具有较高的相对丰度。14个站位浮游动物平均密度为707.53±378.34 ind/m³,各站位浮游动物丰度、物种组成及优势种存在差异。形态学方法共鉴定出11门17纲18目共86个物种，18S V9分子方法鉴定出22门46纲85目共233个操作分类单元(operational taxonomic units, OTUs),分子鉴定的物种覆盖度更高，且代表性类群相对丰度和多样性指数在大部分站位与形态学鉴定结果呈现出显著相关性，表明宏条形码技术鉴定方法与形态学鉴定方法在评价海洋浮游动物多样性方面具有较好的可比性，在我国海洋浮游动物群落监测中具有较高的应用潜力。但由于目前浮游动物的分子鉴定方法仍处于初...

Comparative morphology and metabarcoding analysis of zooplankton diversity in Xisha Islands in the South China Sea

With the largest sea area in the South China Sea, Xisha Islands are rich in marine resources. To understand the composition and distribution characteristics of zooplankton in this area, a comprehensive survey of 14 stations in Xisha Islands was conducted in May 2019. Morphological methods and metabarcoding methods based on 18S V9 sequencing was used to examine the composition of zooplankton samples. We found that the main zooplankton species in Xisha Islands were copepods, Malacostraca and Sagittoidea, of them the relative abundance was both high by morphological and molecular identification. The average zooplankton density in the 14 stations was 707.53±378.34 ind/m³ while it varied with zooplankton abundance, species composition and dominant species among the stations. Compared with morphological identification (86 species from 11 phylum, 17 classes, 18 orders), many more species were obtained by 18S V9 identification (233 OTUs from 22 phylum, 46 classes, 85 orders) and the relative abundance of representative categories and diversity index showed significant correlation with morphological identification in most stations, indicating that the metabarcoding technique and morphological identification method have good comparability in the evaluation of species diversity, and metabarcoding technique exhibited high application potential in efficient assessment of marine biodiversity. However, due to molecular methodology for zooplankton species identification is still in its infant stage, the relevant database is still not complete, and a variety of methods are still needed for the accuracy diversity assessment of zooplankton.