中文摘要：

大型底栖动物在河流生态系统中发挥着重要作用，2003年6月至2004年6月间对汉江流域2级河流——黑竹冲河大型底栖动物群落优势种类的生产力进行为期一周年的调查研究，并对其生产量的营养基础进行了初步分析，结果表明，主要优势种蚋（Simulium sp．）的生活史为一年一代，成虫羽化主要发生在冬季；种群生物量和多度在12月到峰值，分别为115ind．·m^-2，250．9mg·m^-2；采用龄期频率分布法（size-frequency method）测算的周年生产量为3．9216g·m^-2·a^-1，P／B为4．6。在其前肠内含物中，无形态碎屑、真菌和硅藻所占比例分别为60．40％、3．91％和35．96％，对生产量的贡献率分别为：32．2％、10．4％和57．4％。

英文摘要：

Macrozoobenthos community plays an important role in material cycle and energy flow in riverine ecosystem. During the period of June, 2003 to June 2004, an investigation on the life cycle and production of the dominant species of macrozoobenthos community in a second-grade river of Hanjiang River catchment was carded out. From the upper reach to the lower reach of Heizhuchong stream, we chose six types of habitats to sample. At each station, two quantitative samples were taken with a 167μm Surber net, and the samples were sieved with a 167μm net, sorted in a porcelain dish with naked eye. The samples were kept in 10% formalin for later processing. The life cycle of the Simulium sp. population was analyzed by the monthly size-class frequency distribution, the cohort and annual production were estimated by size frequency method. The results showed that the dominant species Simulium sp. appeared to develop one generation for one year, the reproduction occurred from April to August, but mainly in middle three months. The abundance and biomass of the population reached their peaks in December with the values of 115 ind·m^-2 and 250.9mg·m^-2. The estimated cohort and annual production by size-frequency method were 3.9216g.·m^2·a （wet wt）, and the cohort P/B ratios was 4.6, which equals to the annual one. By analyzing its fore-gut content, the proportions of amorphous detritus, fungi and diatoms were 60.40%, 3.91%, 35.96%.Therefore, the contribution rates of the above types of food to secondary production were 32.2%, 10.4%, 57.4%.