基于环境DNA metabarcoding的中街山列岛鱼类物种多样性

Fish species diversity in the Zhongjieshan Islands based on environmental DNA metabarcoding

岛礁生境支撑着极高的水生生物多样性,而鱼类物种多样性是水生生物多样性的重要组成部分。为准确了解岛礁海域的鱼类时空分布格局和多样性特征,依靠传统的渔业资源调查方式存在诸多的困难与挑战,亟需建立灵敏、高效的生物多样性监测方法。本研究于2019年在中街山列岛海域设置了4个采样站位,并在2、5、8和11月等4个时间采集海水表层样品,采用环境DNA metabarcoding技术进行高通量测序。结果显示,中街山列岛近岸海区共检测出鱼类37种,隶属于10目26科36属;鱼类种数呈现夏季>冬季>秋季>春季的趋势;四季共有种仅2种,约占鱼类总种数的5.41%;只在一个季节被检测出的鱼类约占总种数的54.05%。结合NMDS分析和ANOSIM检验的结果显示,鱼类群落在不同季节间有显著差异,而在不同站位间无显著差异。鱼类群落的均匀度较为稳定,多样性和丰富度指数在站位间无明显变化,但在季节间表现为夏季最高、春季最低。研究表明,中街山列岛近岸海区的鱼类分布受季节影响较大,而在不同采样站位的差异不大,可能受站位较为集中的影响。

Rocky reef habitats are critical for supporting exceptionally high fish species diversity,a vital element of biodiversity.However,monitoring fish species in these habitats using traditional fisheries resource survey meth-ods poses significant challenges.Therefore,there is an urgent need to develop sensitive and efficient methods for biodiversity monitoring.Four sampling stations were strategically selected around the Miaozihu Islands within the Zhongjieshan archipelago,and surface seawater samples were collected across four seasons(February,May,August and November in 2019).The spatial and temporal distribution of fish was analyzed using environmental DNA metabarcoding technology.The findings revealed a total of 37 fish species across 10 orders 26 families 36 genera.The seasonal abundance of fish species followed a trend of summer>winter>autumn>spring.Remark-ably,only 2 fish species were observed in all four seasons,representing approximately 5.41%of the total species count,while 54.05%of the species were detected in a single season only.The non-metric multidimensional scal-ing(NMDS)analysis and the analysis of similarities(ANOSIM)test indicated significant variation in fish compos-ition among seasons(P<0.05),but not among stations.The fish community's uniformity remained relatively stable.Although the diversity and richness indices did not exhibit significant differences among stations,they peaked in summer and troughed in spring.Overall,the distribution of fish in the coastal waters of the Zhongjie-shan Islands is significantly influenced by the seasonal changes rether than station locations.This study introduces an innovative,environmentally friendly approach to fish diversity assessment in marine environments akin to those of the Zhoushan islands and reefs,offering valuable technical insights for the management and conservation of fisheries resources.