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2014年6月至2015年5月在杭州湾北部水域设置10个站点,按月以大型仔稚鱼网对该水域进行仔稚鱼资源调查,并与2013年1-12月的研究结果对比,旨在探明杭州湾北部水域仔稚鱼资源的年变动。本研究共采集仔稚鱼96 118尾,平均密度为0.79 ind./m3,隶属于23科55种,个体数、种类数和平均密度均小于2013年。两年共有种类有46种,且优势种均为髭缟虾虎鱼(Tridentiger barbatus)、棘头梅童鱼(Collichthys lucidus)和凤鲚(Coilia mystus)。两年间仔稚鱼发育阶段组成,均以前弯曲期仔鱼为主。对两年仔稚鱼密度分布分析表明,各站位仔稚鱼密度分布差异显著(P<0.05);月份间仔稚鱼密度分布差异不显著(P>0.05)。多样性分析表明两年多样性指数季节性变化明显,均在夏季较高、冬季较低。本次调查夏季Margalef丰富度指数(D)、Shannon-Wiener指数(H’)和Pielou均匀度指数(J’)均高于2013年夏季。
From June 2014 to May 2015, 10 sites were set up in the northern part of Hangzhou Bay. Juvenile fish resources were surveyed on large scale juvenile nets on a monthly basis. Compared with the results of January-December 2013, The annual changes of juvenile larvae resources in the northern part of Hangzhou Bay were ascertained. In this study, 96 118 larvae of juveniles were collected, with an average density of 0.79 ind./m3, belonging to 55 families of 23 families. The number of individuals, the number of species and the average density were all less than those of 2013. There are 46 species in two years, and the dominant species are Tridentiger barbatus, Collichthys lucidus and Coilia mystus. Two years of larvae developmental stages of the composition, are mainly curved larvae before. Analysis of density distribution of juvenile larvae in two years showed that there was significant difference in density distribution of larvae (P <0.05). There was no significant difference in density distribution of larvae between months (P> 0.05). The diversity analysis showed that the seasonal diversity of the two-year diversity index was obvious, both in summer and winter. The summer Margalef abundance index (D), Shannon-Wiener index (H ’) and Pielou evenness index (J’