杭州湾北部水域仔稚鱼种类组成和多样性研究

Study on the species composition and diversity of fish larvae and juveniles in the north of Hangzhou Bay

2013年1月至12月,在杭州湾北部水域设置10个站点,按月用大型仔稚鱼网(口径1.3 m,网目0.5 mm)进行了12个航次的调查,共采集到鱼卵81粒,隶属于4科6种;仔稚鱼143 782尾,隶属于23科69种。其中河口型鱼类(34种)和海洋型鱼类(24种)多于洄游型鱼类(4种)和淡水型鱼类(7种)。鱼卵中以棘头梅童鱼(Collichthys lucidus)居多,而仔稚鱼中个体数最多的是髭缟虾虎鱼(Tridentiger barbatus),占总渔获物的62.88%,其后依次为棘头梅童鱼(13.02%)、凤鲚(Coilia mystus,9.22%)、黄鳍刺虾虎鱼(Acanthogobius flavimanus,2.56%)、斑尾刺虾虎鱼(Acanthogobius ommaturus,2.32%)。前弯曲期仔鱼占总渔获物数量的89.12%,6月最多(85.31%)。春夏两季仔稚鱼物种数和密度要显著高于秋冬两季,6月密度急剧增高,达到13.50个/m3,7月物种数最多(18种)。Margalef丰富度指数(D)总体变化较大,月间变化相对剧烈,7月最高,Shannon-Wiener指数(H')和Pielou均匀度指数(J')变化幅度相对较小。

To clarify the species composition and diversity of fish larvae and juveniles in the north of Hangzhou Bay, monthly collections were held by a larva net （1.3 m mouth-diameter, 0. 5 mm meshaperture） from January to December, 2013. There are 10 sample stations in this study. A total of 81 eggs belonging to 6 species from 4 families and a total of 143,782 individuals of more than 69 species from 23 families were collected. The number of estuarine species and marine species was 34 and 24 respectively, greater than that of diadromous species （4 species） and fresh water species （7 species）. Collichthys lucidus is in the majority among eggs. The most dominant species of them was Tridentiger barbatus, accounting for 62.88% of this total abundance, followed by C. lucidus for 13. 02%, Coilia mystus for 9. 22%, Acanthogobius flavimanus for 2.56% and Acanthogobius ommaturus for 2.32%. Fish larvae in preflexion stage accounted for 89. 12% of total abundance and were most in June （85.31%）. Species number and density in spring and summer were significantly higher than those in autumn and winter. The density in June had a sharp increase （ 13.50 ind/m3 ） and the species number in July （ species number = 18） was the greatest of all months. The Margalef index changed greatly overall and sharply between months. The Shannon-Wiener index and Pielou evenness index had smaller changes between months.