福建九龙江口浮宫附近水域鱼类的群落结构变动

Variations of fish community structure in the waters adjacent to Fugong in Jiulongjiang Estuary

2011年1～12月,于每月大潮时采用定置张网在九龙江口浮宫附近水域进行鱼类采样.结果如下:(1)共获得86种鱼类,隶属于12目41科70属,其中鲈形目种类最多,占总数的51.2%,其次是鲱形目11种,其余各目均不超过6种;(2)采用Pinkas相对重要性指数划分标准,九龙江口浮宫附近水域的鱼类群落的全年优势种有4种,常见种9种,偶见种73种,其中优势种分别为裸头双边鱼(Ambassis gymnocephalus)、前鳞骨鲻(Osteomugil ophuyseni)、斑鰶(Konosirus punctatus)和青鳞小沙丁鱼(Sardinella zunasi),4个优势种的重量占渔获总重量的65.4%,其个体数占渔获总个体数的64.2%;(3)对鱼类群落结构起主导作用的种类有13种;(4)洄游性鱼类主要有龙头鱼(Harp-odon nehereus)、鳓(Ilisha elongata)及金色小沙丁鱼(Sardinella aurita)等,洄游至该水域的时期一般为夏季;(5)全年各月的Shannon-Wiener多样性指数变动范围为1.08～1.91,均匀度指数波动于0.36～0.56,而丰富度指数变化幅度为1.38～3.48.聚类分析结果显示,除1、2月间的相似性(72.5%)和10、11月的(62.1%)较高外,其余各月间的相似性均较低.以上结果表明,该水域的鱼类生物群落变动较大,具有较高的不稳定性.

The fish community structure in waters adjacent to Fugong, Jiulongjiang Estuary, is analyzed based on monthly sampling with stake net in 2011. The results are as follows, （ 1 ） there are 86 species of fish, belonging to 70 genus, 41 families and 12 orders in this waters, where Perciformes is the largest order accounting for 51.2% of the total number of species and Clupeiformes with 11 species is the secondary. The rest orders are all less than 6 species. （2） with the method of IRr, it is confirmed that there are 4 dominant species year round, 9 common species and 73 rare species in the community. Four dominant species are Ambassis gymnocephalus, Mugil ophuyseni, Clupanodon punctatus and Sardinella zunasi. These dominant species account for 65.4% of biomass and 64.2% of a bundance. （3）There are 13 species playing a leading role in the community structure of fishes. （4）Important catad romous fish includes Harpodon nehereus, Ilisha elongate and Sardinella aurita, which generally migrate to this area in summer. （5） The result of community diversity analysis shows that monthly ShannonWiener diversity index range from 1.08 to 1.91. Evenness index range from 0. 36 to 0. 56 and Richness index from 1.38 to 3.48. The result of cluster analysis shows that the similarity between January and February is 72. 5 %, the similarity between October and November is 62.1%, and the similarities in the other months are less than 60%. The result of community di versity and cluster analysis show that the fish community in waters adjacent to Fugong has a high instability.