| 摘要: |
| 大型底栖动物群落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优势种类的生活史和生产力进行为期一周年的研究．结果表明:主要优势种圆顶华溪蟹(Sinopotamon teritisum Dai et al．)生活史周期基本为四年,每年8-10月为主要繁殖季节,衰老个体(体宽>29 mm)在每年的1～2月份死亡较多;现存量在一周年中变化较大,密度9月份达到峰值,为35ind/m2,生物量在6月达到峰值,为41．7 g/m2;采用体长频率分布法(size-frequency method)测算的周年生产量为151.3071g/(m2．a)>,P/B系数为1．4．在其胃内含物中,无形态碎屑占45．4%,虾占10．9%、水生昆虫占35．6%、螺占5．7%、植物组织占8．1%,对次级生产量的贡献率分别10．84%、18．21%、59,49%、9．52%和1．94%． |
| 关键词: 大型底柄动物 群落 圆顶华溪蟹 生产量 黑竹冲河 |
| DOI：10.18307/2006.0418 |
| 分类号: |
| 基金项目:国家自然科学基金(30270278)资助． |
|
| Secondary production and trophic basis of sinopotamon teritisum in Heizhuchong Stream, Hanjiang Catchment |
|
YAN Yunjun, LI Xiaoyu
|
|
School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
|
| Abstract: |
| 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-order river of Hanjiang River Basin was carried out. From the upper to the lower reach of Heizhuchong stream, we chose six types of habitats to collect quantitative samples. Station 1 (SI) lied in the middle of the stream with big round rocks in the upper reach，station 2 (S2) was in the inner part of a weir with cobble substratum，station 3 (S3) in the middle of a peacefully flowing section with gravel-sand bottom, station 4 (S4) at the side of the riparian with aquatic macrophytes and snags, station 5 (S5) in the middle of the riffle, station 6 (S6) at the lower reach with a sewage outlet ca 100 meters uppstream. At each station, four quantitative samples were taken with a 167um D-frame kick net or a Surber net, and the samples were sieved with a 167um net, sorted in a porcelain dish with naked eye. The specimens were kept in 10% formalin for later processing. The life cycle of the S. teritisum Dai et al. population was analysed by the monthly size-class frequency distribution, the cohort and annual production were estimated by size frequency method. The results showed that S. teritisum completed one generation for nearly 4 years，the reproduction mainly occurred in from middle August to middle October, and most of the senescent individuals died in February. The abundance of the population varied greatly during the year, probably due to the relatively smaller sampling area compared with the strong activity of motion of S. teritisum. Whereas, the variation of the biomass followed the same pattern of the abundance. The abundance attained its peak in September with 35 ind/m2，and biomass reached its highest level in June at 41.7 g/m2. The estimated cohort production and cohort P/B ratio by size-frequency method were 605.2g/(m2 · a) (wetwt) and 5.5，respectively； the annual production and P/B ratio were 151. 3g/(m2 · a) (wetwt) and 1.4. The reason why the annual production of the animal in Heizhuchong Stream was the relatively higher was because of its high density. By analyzing its stomach content, the proportions of amorphous detritus, caridina，aquatic insect larvae, gastropods and vascular tissues were 45.4%, 10. 9%, 35. 6%, 5.7%, 8.1% . Therefore, the contribution rates of the above types of food to production were 10.84%, 18.21%, 59.49%，9.52%，and 1.94%, respectively. |
| Key words: Macrozoobenthos community production Sinopotamon teritisum Heizhuchong Stream |
