太湖新银鱼种群摄食对小江浮游动物群落结构的影响  

Effects of Neosalanx taihuensis Feeding on Zooplankton Community Structure in Xiaojiang River

作　　者：张三峰 沈建忠[1] 万成炎[2] 吉芬芬 胡莲[2] 邱龙辉 彭乐根 朱稳 ZHANG San-feng;SHEN Jian-zhong;WAN Cheng-yan;JI Fen-fen;HU Lian;QIU Long-hui;PENG Le-gen;ZHU Wen(College of Fisheries,Huazhong Agricultural University,Wuhan 430070,P.R.China;Key Laboratory of Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem of Ministry of Water Resources,Institute of Hydroecology,Ministry of Water Resources and Chinese Academy of Sciences,Wuhan 430079,P.R.China)

机构地区：[1]华中农业大学水产学院,湖北武汉430070 [2]水利部中国科学院水工程生态研究所,水利部水工程生态效应与生态修复重点实验室,湖北武汉430079

出　　处：《水生态学杂志》2024年第3期138-147,共10页Journal of Hydroecology

基　　金：国家自然科学基金项目(51779157,51679153)。

摘　　要：明晰太湖新银鱼(Neosalanx taihuensis)种群生长与浮游动物群落结构的动态变化关系,可为小江水华暴发的控制与水生态健康管理提供理论依据。2019年逐月对小江太湖新银鱼与浮游动物样品进行采集,并分析太湖新银鱼胃含物组成与浮游动物群落结构特征。结果表明:(1)太湖新银鱼的饵料生物主要为桡足类,其次为枝角类,轮虫占比较少;(2)3月至6月(太湖新银鱼春群繁殖期)太湖新银鱼生物量迅速上升,而浮游动物群落结构在此期间呈小型化趋势,生物量由28.93 mg/L下降至1.13 mg/L,密度由21173.39个/L增加至26808.23个/L;7月小江禁捕结束,太湖新银鱼生物量开始急剧下降,小江浮游动物中桡足类和枝角类的密度与生物量迅速升高,于8月达到全年最高;(3)由于太湖新银鱼对枝角类和桡足类具有较强的选择性,故在其生物量较高的时期(5、6月),水体中枝角类和桡足类生物量占比显著低于其他时期(P<0.05)。由此认为,太湖新银鱼生物量与浮游动物群落结构变化存在较强的关联性,太湖新银鱼种群摄食的下行效应可能是小江浮游动物生物量下降及群落结构小型化的关键原因。In this study,we explored the effect of Neosalanx taihuensis feeding on zooplankton community structure in Xiaojiang River,a typical tributary of Three Gorges Reservoir.Our aim was to provide a theoretical basis for fishery management and ecological restoration of Xiaojiang River.From January to December 2019,N.taihuensis and zooplankton were collected monthly at three sections in the upper,middle and lower Xiaojiang River,and the stomach contents of N.taihuensis,and zooplankton community structure were analyzed.Results show that:(1)During the investigation,a total of 334 N.taihuensis specimens,and their stomach contents,were sampled.The primary feeding organisms for N.taihuensis were Copepods,followed by Cladocerans and Rotifers,with relative importance indices of 79.97% 18.86% and 0.001%,respectively.(2)From March to June,the biomass of N.taihuensis increased rapidly,while the zooplankton community tended toward miniaturization.Zooplankton biomass decreased sharply from 28.93 mg/L to 1.13 mg/L while the density increased from 21173.39 ind/L to 26808.23 ind/L.When the fishing ban period ended in July,the biomass of N.taihuensis began to decline sharply while the density and biomass of Copepods and Cladocerans increased rapidly,peaking at 151.98 ind/L and 3.39 mg/L in August.(3)During the rapid growth period of N.taihuensis in May and June,the biomass proportions of Cladocerans and Copepods was significantly lower(17%-58%)than at other times(P<0.05).The strong correlation between N.taihuensis biomass and zooplankton biomass,and the results of stomach content analysis,clearly show that N.taihuensis foraging affects zooplankton community structure.The topdown effect of N.taihuensis feeding explains the decline of zooplankton biomass and the miniaturization of zooplankton community in the Xiaojiang River.Clarifying the extent and timing of the dynamic relationship between N.taihuensis growth and zooplankton community structure provides a theoretical basis that supports coordinated efforts to control algal blooms and

关 键 词：太湖新银鱼 选择性摄食 浮游动物 下行效应 三峡水库 小江 

分 类 号：Q958.8[生物学—动物学]