中文摘要：

根据2012年春季和秋季长江口及邻近海域无脊椎动物的底层拖网资料和环境调查数据，分析了该海域春、秋季无脊椎动物群落结构特征及其与环境因子的关系。结果表明，长江口及邻近海域2个季节共捕获无脊椎动物5目14科25种，其中甲壳动物是最主要的无脊椎动物类群。长江口无脊椎动物资源量占优势的种类包括三疣梭子蟹（Portunus trituberculatus）、脊腹褐虾（Crangon af fihis）、细点圆趾蟹（Ovalipes punctatus）和葛氏长臂虾（Palaemon gravieri），春季和秋季对无脊椎动物资源量贡献最大的种类不同。各站次Margalef种类丰富度指数（D）的范围在0．31～2．02之间，Shannon-Wiener多样性指数（H′）的范围在0．37～1．92之间，Pielou均匀度指数（J′）的范围在0．17～0．95之间。春季和秋季长江口无脊椎动物资源量和多样性季节间变异不显著。等级聚类分析（CLUSTER）和非参数的多维标度排序（NMDS）分析表明，无脊椎动物样本可以区分为春季组与秋季组2个组群。单因子相似性分析（ANOSIM）表明，春、秋季组群间无脊椎动物群落结构差异极显著。典型对应分析（CCA）表明，表层磷酸盐、底层溶解氧、底层硅酸盐和底层硝酸盐是影响长江口及邻近海域无脊椎动物群落结构变异的主要环境因子。长江口无脊椎动物季节变异主要体现在种类的季节演替上，营养盐和溶解氧浓度是无脊椎动物种类季节分布的主要限制因素。

英文摘要：

Based on the the bottom trawl survey results of invertebrate and investigation data of environmental factors in Yangtze River Estuary and its adjacent waters in Spring and Autumn, 2012, the invertebrate community structure and its relationship with environmental factors during spring and autumn were analyzed. The results indicated that 25 invertebrate species were caught, belonging to 5 orders and 14 families, among which, crustaceans were the major components. The species which have the high abundance and biomass included Portunus trituberculatus, Crangon a f finis, Ovalipes punctatus, Palaemon gravieri and so on. The Margalef＇s species richness index （D）, Shannon-Wiener diversity index （H′） and Pielou＇s evenness index （J′） of different site ranged from 0.31-2.02, 0. 37-1.92 and 0.17-0. 95, respectively. There was no significant difference between spring and autumn in abundance, biomass and each diversity index （P〉0.05）. CLUSTER and NMDS analysis results showed that invertebrate community during spring and autumn could be clustered into two groups which were spring and autumn assemblages. ANOSIM analysis indicated significant differences in community structure between these two groups （R = 0. 68, P〈0.01）. CCA analysis indicated that surface phosphate, bottom dissolved oxygen, bottom silicate and bottom nitrate were the major environmental factors affecting the invertebrate community structure in the Yangtze River Estuary and its adjacent waters. It can be drawn that the seasonal variation of invertebrates in the Yangtze River Estuary is reflected in the seasonal succession of species. Concentration of nutrient and dissolved oxygen are the main limiting factors affecting the seasonal distribution of invertebrates.