赣江下游及其支流浮游甲壳动物的群落结构

The community structure of crustacean zooplankton in the lower reaches and its tributary of the Ganjiang River

2009年6月、11月和2010年4月对赣江下游浮游甲壳动物的群落结构和时空变化进行研究。共记录浮游甲壳动物21种,其中枝角类14种、桡足类7种。脆弱象鼻溞Bosmina fatalis、微型裸腹溞Moina micrura和中剑水蚤Mesocyclops sp.为优势种。赣江下游干流浮游甲壳动物的最大平均密度和生物量(11.1ind.·L^(-1)和0.127mg·L^(-1))均出现在6月,最小值(1.59ind.·L^(-1)和0.01mg·L^(-1))均出现在4月。袁河支流的枝角类和桡足类密度在6月(4.97±13.28ind.·L^(-1)和2.07±4.85ind.·L^(-1))和11月(2.07±5.21ind.·L^(-1)和2.24±5.22ind.·L^(-1))高于赣江下游干流和锦江支流。香农-威纳指数(H′)和马加利夫指数(d)表明赣江下游及其支流水质为中度污染或重污染。水温和小型浮游植物生物量是影响赣江下游浮游甲壳动物密度时空变化的重要因素。

The community structure and temporal-spatial variations of crustacean zooplankton in the lower reaches of Ganjiang Riverwere investigated in June and November 2009 and April 2010. A total of 21 species were recorded, among which 14 species were cladocerans and 7 species were copepoda. B. fatalis, M. micrura and Mesocyclops sp. were dominant species during the study. Mean maximal density and biomass （11.1 ind·L^-1 and 0.127mg·^-L1） of crustacean zooplankton in main stream of the lower reaches of Ganjiang River occurred in June while the mimimun （1.59 ind·L^-l and 0.01mg·L^-1） appeared in April. The densities of cladocerans and copepoda in the Yuanhe tributary of Ganjiang River in June （4.97±13.28 ind·L^-1and 2.07±4.85 ind·L^-1） and November （2.07±5.21 ind·L^-1 and 2.24±5.22 ind·L^-l） were higher than in the main stream and Jingjiang tributary of Ganjiang River. Shannon-Wiener index （H＇） and Margalef index （d） showed that water quality in the lower reaches and its tributaries of Ganjiang River was moderate contamination or serious contamination. Water temperature and edible phytoplankton biomass were important factors affecting temporal and spatial variations of crustacean zooplankton.