千岛湖浮游甲壳类群落结构特征初步研究

Community structure of microcrustaceans in Qiandao Lake

研究了浙江千岛湖2004年浮游甲壳类的群落结构组成及现存量的时空变化。千岛湖浮游甲壳类主要由33种组成,其中桡足类14种,优势种为右突新镖水蚤(Neodiaptomus schmackeri)、特异荡镖水蚤(Neutrodiaptomus tumidus)、球状许水蚤(Schmackeria forbes)、近邻剑水蚤(Cyclops vicinuss)等;枝角类19种,优势种为透明溞(Daphnia hyaline)、象鼻溞(Bosminaspp)、短尾秀体溞(Diaphanosoma brachyurum)等。桡足类年平均密度为8.26±1.25 ind/L,年均生物量为0.13±0.09 mg/L,物种多样性指数为1.88;枝角类年平均密度为5.27±1.33 ind/L,年均生物量为0.42±0.23 mg/L,物种多样性指数为3.03。桡足类和枝角类密度均在8月份出现峰值,分别为42.76 ind/L和30.57 ind/L;水平分布上,千岛湖浮游甲壳类现存量在Ⅰ站点(宅上)最高,生物密度和生物重量分别达130.83 ind/L、7.83 mg/L,Ⅵ站点(湖村岛)最低,生物密度和生物重量仅有25.20 ind/L和2.93 mg/L。垂直分布以离水表8 m的生物量最高,分别为242.27 ind/L、13.98 mg/L。

The community structure of microcrustaceans （copepod and cladocera ） including species composition, standing crop dynamics and diversities was studied in Qiandao Lake in Zhejiang Province of China in 2004. During the period of survey, 14 species of copepods including four dominant species, Neodiaptomus schmackeri, Neutrodiaptomus tumidus, Schmackeria forbes, Cyclops vicinu and 19 species of cladocera including three dominant species, Daphnia hyaline, Bosmina spp. and Diaphanosoma brachyurum were found in Qiandao Lake. The average density of copepod and cladocera was 8.26 ± 1.25 and 5.27 ±1.33 ind/L respectively, the average biomass of them was 0.13 ± 0.09 and 0.42 ± 0.23 mg/L, and Margelef＇ s diversity index was 1.88 and 3.03 respectively. In the horizontal distribution, the highest density of copepod and cladocera appeared both in August （42.76 ind/L and 30.57 ind/L）. The highest standing crops appeared at sampling site I, and the corresponding density and biomass are 130.83 ind/L and 7.83mg/L; the lowest are 25.20 ind/L and 2.93 mg/L that occurred at sampling site VI. In the vertical distribution, the highest standing crop of microcrustaceans was found at the water depth of 8m.