赣江下游及其支流轮虫群落结构及水质生物学评价

Community structure of rotifers and biological evaluation of water quality in the lower reaches and its tributary of the Ganjiang River

2009年6月(丰水期)、11月(枯水期)和2010年4月(平水期)对赣江下游轮虫群落结构的时空变化进行研究。共记录了轮虫21属26种。针簇多肢轮虫(Polyarthra trigla)、前节晶囊轮虫(Asplanchna priodonala)和扁平泡轮虫(Pompholyx complanata)为优势种。赣江下游干流轮虫的最大平均密度和生物量(6.6 ind·L·1和0.031 mg·L·1)出现在11月,最小值(1.7 ind·L·1和0.006 mg·L·1)出现在4月。袁河支流的轮虫密度在6月(15.4±35.4 ind·L·1)、11月(8.3±15.4ind·L·1)和4月(13.0±28.8 ind·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。赣江下游及其支流的轮虫密度的时空变化与浮游甲壳动物生物量、pH和小型浮游植物生物量密切相关。

The temporal-spatial variations of rotifer community structure in the lower reaches of Ganjiang River were investigated in June （wet season） and November （dry season） 2009 and April （normal-water period） 2010. A total of 26 species from 21 genera were recorded. Polyarthra trigla, Asplanchna priodonala and Pompholyx complanata were dominant species during the study. Mean maximal density and biomass （6.6 ind.L-1 and 0.031 mg.L-l） of rotifers in main stream of the lower reaches of Ganjiang River occurred in November while the minimum （1.7 ind.L-1 and 0.006 mg·L^-1） appeared in April. The densities of rotifers in the Yuanhe tributary of Ganjiang River in June （15.4±35.4 ind.L-1）, November （8.3±15.4 ind.L-1） and April（13.0±28.8 ind.L-1） were higher than in the main stream and Jingjiang tributary of Ganjiang River. Shannon-Wiener index （H＇） and Margalef index （at） showed that water quality in the lower reaches and its tributaries of Ganjiang River was moderate contamination or serious contamination. It indicated that rotifers density was closely correlated with crustacean zooplankton, pH and phytoplankton biomass in the lower reaches and its tributaries＇of Ganjiang River.