基于形态学鉴定与eDNA技术的于桥水库鱼类多样性分析

Analysis of fish diversity in Yuqiao Reservoir based on morphological identification and eDNA technology

摘要

【目的】明确于桥水库鱼类多样性现状,对比形态学鉴定与环境DNA(eDNA)技术在鱼类资源调查中的应用效果,为水库水生态环境保护提供数据支撑。【方法】2022—2023年,采用三层定置刺网与地笼在5个站位捕捞鱼类并进行形态学捕捞鉴定,结合Pinkas相对重要性指数分析优势种,通过生态位宽度与重叠模型解析种间关系;2023年5—10月同步采集各站位eDNA样品,基于12S rDNA基因引物进行PCR扩增与高通量测序,并完成物种注释,利用α多样性指数分析群落特征。【结果】形态学鉴定共捕获鱼类24种,隶属于5目10科23属,鲤形目占比66.67%,优势种为鲤、子陵吻虾虎鱼等6种,占渔获物生物量的72.34%;主要鱼类生态位宽度范围0.07~1.12,无广生态位物种,276个种对中25.72%存在显著重叠,鲤形目鲤科鱼类重叠程度最高。eDNA技术注释鱼类25种,隶属于5目11科18属,鲤、鳙平均相对丰度分别达38.53%、21.96%;S4站位Chao1指数(41)和Shannon指数(2.236 4)最高,S18站位最低(Shannon指数1.399 4)。两种方法共有种类占比12.8%,综合分析显示水库可能存在40种鱼类。【结论】于桥水库鱼类以鲤形目为主,群落结构受环境异质性影响显著,eDNA技术可有效补充形态学鉴定的局限性,二者结合能更全面评估鱼类多样性,为库区生态保护提供了科学依据。

Abstract

[Objective] To clarify the current status of fish diversity in Yuqiao Reservoir, compare the application effectiveness of morphological identification and environmental DNA(eDNA) technology in fish resource surveys, and provide data support for protection of the reservoir's water ecological environment. [Methods] From 2022 to 2023, fish were collected using three-layer gillnets and ground cages at five sampling sites, followed by morphological identification. Dominant species were analyzed using the Pinkas index of relative importance, and interspecific relationships were analyzed using niche breadth and overlap models. From May to October 2023, eDNA samples were collected synchronously at each sampling site. PCR amplification and highthroughput sequencing were performed based on 12 S r DNA gene primers, species annotation was completed, and community characteristics were analyzed using α-diversity indices. [Results] A total of 24 fish species were captured through morphological identification, belonging to 5 orders, 10 families, and 23 genera. Cypriniformes accounted for 66. 67%. Six dominant species, including Cyprinus carpio and Rhinogobius giurinus, accounted for 72. 34% of the total catch biomass. The niche breadth of major fish species ranged from 0. 07 to 1. 12, with no broad-niche species observed. Significant overlap was observed in 25. 72% of the 276 species pairs, and the degree of overlap was highest among Cyprinidae species within Cypriniformes. A total of 25 fish species were annotated using eDNA technology, belonging to 5 orders, 11 families, and 18 genera. The average relative abundances of Cyprinus carpio and Aristichthys nobilis reached 38. 53% and 21. 96%, respectively. The Chao1 index(41) and Shannon index(2. 236 4) at station S4 were the highest, while station S18 showed the lowest values(Shannon index 1. 399 4). 12. 8% of species were detected by both method, and comprehensive analysis indicated that approximately 40 fish species may be present in the reservoir. [Conclusion] Fish in Yuqiao Reservoir are dominated by Cypriniformes, and the community structure is significantly influenced by environmental heterogeneity. eDNA technology can effectively complement the limitations of morphological identification, and the combination of both method enables a more comprehensive assessment of fish diversity, providing a scientific basis for ecological protection in the reservoir area.

关键词

环境DNA / eDNA技术 / 于桥水库 / 鱼类多样性 / 生态位宽度 / 生态位重叠 / 形态学鉴定 / 影响因素

Key words

environmental DNA / eDNA technology / Yuqiao Reservoir / fish diversity / niche breadth / niche overlap / morphological identification / influencing factors

基金资助

国家自然科学基金项目(32172978)

天津市淡水养殖产业技术体系创新团队-养殖水环境调控岗位项目(ITTFRS2021000-009)

天津市教委科研计划项目(2020ZD06)

天津市教委科研计划项目(2021KJ110)

天津市大学生创新创业训练计划项目(202410061161)