长江刀鲚国家级水产种质资源保护区(安庆段)浮游动物群落结构

Community Structure of Zooplankton in the National Aquatic Germplasm Resources Conservation Area of the Coilia Nasus in the Anqing Section of the Yangtze River

为掌握长江刀鲚国家级水产种质资源保护区(安庆段)(简称“保护区”)浮游动物群落结构现状,于2020年8月、10月和2021年1月在该区域开展浮游动物调查,调查共鉴定出浮游动物31属56种,其中原生动物9属16种,轮虫13属29种,枝角类5属6种,桡足类4属5种;保护区浮游动物优势种共6种,均为原生动物和轮虫,其中针簇多肢轮虫(Polyarthratrigla)为3个季节共有优势种;保护区浮游动物平均密度为495.65 ind./L,平均生物量为0.37 mg/L,其中原生动物和轮虫是浮游动物密度的主要组成部分,生物量的主体则是轮虫;浮游动物物种数及现存量呈现出季节差异,其中三者均在夏季最高,物种数最少的季节为冬季,密度和生物量的最小值则为秋季;空间上,保护区浮游动物物种数和现存量表现为实验区高于核心区,有通江入河口的1#断面及有沙洲分流的分汊汇合水域的4#断面浮游动物现存量较高,在长江干流中这两种水域更利于浮游动物的生存与繁育。整体上,保护区浮游动物较为丰富,生态环境较优,是长江刀鲚较为理想的繁育场所。

To understand the community structure of zooplankton,a field investigation of zooplankton was conducted in the National Aquatic Germplasm Resources Conservation Area of the Coilia nasus in the Anqing Section of the Yangtze River in August,October of 2020,and January,2021.The results showed that 31 genera and 56 species of zooplankton were monitored,including 9 genera and 16 species of Protozoa,13 genera and 29 species of Rotifera,5 genera and 6 species of Cladocera,4genera and 5 species of Copepoda.A total of 6 dominant species were recorded throughout the whole year,all of which were protozoa and rotifers.Polyarthra trigla was the three seasons share dominant species;The annual average density and biomass of zooplankton was 495.65 ind./L and 0.37 mg/L,respectively.Protozoa and rotifers were the main components of zooplankton density,and the main part of biomass was Rotifers.The community structure of zooplankton differed seasonally as the number of species and existing stocks were highest in Summer,the season with the least number of species was in Winter,and the minimum of density and biomass was in Autumn;Spatially,the number of zooplankton species and the existing stock in the experimental area of the conservation was higher than that in the core area.The number of zooplankton species in section 1#with the estuary of the Yangtze River and section 4#in the sub-branched confluence wat1er area with the estuary of the river was higher.Such waters were more conducive to the survival and breeding of zooplankton.On the whole,the conservation area was rich in zooplankton and had a better ecological environment.It was an ideal breeding place for C.nasus in the Yangtze River.