Abstract:

To monitor fish resources and biodiversity in the headwaters of Chishui River,a comprehensive investigation was conducted using both traditional catch methods and environmental DNA (eDNA) technology from 2020 to 2021.A total of 48 fish species were identified,representing 4 orders,10 families,and 41 genera.Traditional fishing methods captured 23 fish species,spanning 2 orders,5 families,and 22 genera,while eDNA technology expanded the detection to encompass 4 orders,8 families,38 genera,and 40 species.In the analysis of fish species composition,the relative importance index (IRI) highlighted Schizothorax grahami,Acrossocheilus yunnanensis,Zacco platypus,and Semilabeo prochilus as the dominant species in the river section of the reserve.The Shannon-Wiener index registered at 2.99,indicating relatively rich overall fish resources and a relatively stable community structure.The catch Margalef index (D) reached 3.31,affirming the richness of fish species in the monitoring area,with a stable composition and population structure.Further assessment revealed a catch evenness index of 0.66,indicating a uniform distribution of population structure.Notably,differences in fish resources between the main river and tributaries were observed.Based on these findings,future conservation efforts should prioritize the core protection zone of the main stream,enhancing measures for fish diversity protection.Additionally,targeted interventions to restore tributary resources should be progressively implemented to elevate the overall resource level.This study provides valuable insights into the diverse fish species,their distribution,and recommendations for effective conservation strategies in the headwaters of Chishui River.

Key words: the headwaters of Chishui River, fish resources, diversity, eDNA

摘要：

为调查赤水河河源段的鱼类资源及生物多样性状况,于2020—2021年通过传统捕捞方式与环境DNA技术方法对保护区的鱼类资源进行了调查。本次调查共检测到48种鱼类,隶属于4目10科41属,其中传统捕捞方式采集的鱼类有23种,涉及2目5科22属;eDNA技术分析检测出4目8科38属40种。在渔获物种类组成分析中,鱼类相对重要性指数法(IRI)显示昆明裂腹鱼(Schizothorax grahami)、云南光唇鱼(Acrossocheilus yunnanensis)、宽鳍鱲(Zacco platypus)、泉水鱼(Semilabeo prochilus)为保护区调查河段的优势种;渔获物多样性指数(H')为2.99,表明该河段总体鱼类资源相对丰富,群落结构相对稳定;渔获物种类丰富度指数(D)为3.31,表明调查区域鱼类资源种类数相对丰富,生物多样性结构相对完好,鱼类组成及种群结构稳定;渔获物均匀度指数(J)为0.66,表明种群结构分布较均匀,群落结构稳定。同时根据鱼类资源分布特征,发现干、支流在鱼类资源量方面存在差异,在后期鱼类多样性保护上应加强干流保护区核心区的保护,逐步加强支流资源量恢复措施,提升整体资源水平。

关键词: 赤水河河源段, 鱼类资源, 多样性, eDNA