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根据2006~2007年对长江口口门区潮下带鱼类的监测数据,分析了该水域鱼类群落组成的季节变化特征。结果表明:本次调查采获鱼类42种,隶属21科。生态类群以海洋鱼类种类最多(27种),其次为河口定居种(10种),而淡水鱼类、溯河产卵洄游鱼类和降海产卵洄游鱼类种类数很低。S1站点和S2站点类似,均以棘头梅童鱼(Collichthys lucidus)、刀鲚(Coilia ectenes)、龙头鱼(Harpodon nehereus)为优势种。两站点鱼类群落在空间上无显著差异,而时间上均有明显的季节变化,冬季和初春的样品聚为一组(Ⅰ组),夏、秋季的样品聚为一组(Ⅱ组)。通过SIMPER分析可知,两组间的平均相异性较高,达73.03,共有17种鱼类对组间的贡献超过90%,如日本鳗鲡(Anguilla japonica)、棘头梅童鱼、矛尾虾虎鱼(Chaeturichthys stigmatias)、刀鲚、焦氏舌鳎(Cynoglossus joyneri)、龙头鱼等。
Based on the monitoring data of tidal flats in the mouth area of the Yangtze Estuary from 2006 to 2007, the seasonal variation characteristics of fish community composition in this area were analyzed. The results showed that 42 species of fish were collected in this survey, belonging to 21 families. Among the ecotypes, marine fish species are the most abundant (27 species), followed by estuarine species (10 species), while the numbers of freshwater fish, anadromous spawning migratory fish and sea-lowering spawning migratory fish species are very low. The S1 site is similar to the S2 site with the dominant species being Collichthys lucidus, Coilia ectenes and Harpodon nehereus. There was no significant difference in the spatial distribution of fish communities in both sites, but seasonal variation was observed in both sites. Samples in winter and early spring clustered together (group Ⅰ) and summer and autumn (group Ⅱ). By SIMPER analysis, the average dissimilarity between the two groups was high, reaching 73.03. A total of 17 species of fish contributed more than 90% to the groups, such as Anguilla japonica, Fish (Chaeturichthys stigmatias), Daphnia magna, Cynoglossus joyneri, faucet and the like.