团头鲂池塘工业化生态养殖系统中浮游动物群落特征分析

摘要

为研究池塘工业化生态养殖系统中浮游动物群落结构特征,并初步阐明其生态学机理,以团头鲂Megalobrama amblycephala为养殖品种,设置高、低两个养殖密度 (300、200 ind. /m2),采用多样性指数、均匀度指数评价了系统中6个试验分区浮游植物群落结构特征.结果表明:各试验区共鉴定出浮游动物25种、无节幼体1类,其中轮虫14种、枝角类8种、桡足类3种,分别占总种数的56%、32%、12%;种类数、多样性指数、均匀度指数依次均表现为进水区、净化区、循环区、循回区>低密度养殖区>高密度养殖区>排水区;枝角类、桡足类、轮虫丰度依次表现为进水区、净化区、循环区、循回区>排水区>低密度养殖区>高密度养殖区;枝角类、桡足类比例表现为养殖区低于其他各区,而轮虫类比例则相反,表现为养殖区高于其他各区.研究表明:鱼类对浮游动物进行了摄食,且相对于轮虫而言,枝角类和桡足类等较大型浮游动物更易于被鱼类摄食;从生物多样性指数反映的水质状况看,排水区处于中度污染状态,养殖区处于轻度污染状态,其余各区处于清洁状态;除排水区外,其余各试验分区均水质较好,系统运行良好.%The zooplankton community structure was studied in the 6 test partitions in a pond industrial eco-aqua-culture system in a blunt-snout bream Megalobrama amblycephala culture pond at stocking density of 300 ind./m2 (high) and 200 ind./m2(low) by Shannon-Wiener diversity index and Pielou uniformity index in order to evaluate change pattern of zooplankton community structure in pond industrial eco-aquaculture system and to explain the ec-ological mechanism. The results showed that 25 species of zooplankton and 1 class of nauplius were found in the 6 test partitions, including 14 species of rotifer,predominated in species, accounting for 56% of total zooplankton species;8 species of cladoceran, taken second place in species, accounting for 32%; and 3 species of copepod, accounting for 12%.The spatial distribution sequence of zooplankton species number,biodiversity indexes,and uni-formity indexes was expressed as inlet area,purification area,recirculation area,back area >low stocking density area>high stocking density area>outlet area,and the order of biomasses of rotifer,cladoceran and copepod was de-scribed as inlet area,purification area,recirculation area,back area >outlet area >low stocking density area>high stocking density area. There was higher proportion of cladoceran and copepod in aquaculture area than that in other areas,while the proportion of rotifer was lower in aquaculture area than that in other areas,which was involved in zooplankton consumption by the fish,the consumption of larger zooplankton such as cladoceran and copepod being energetically feasible compared to small zooplankton including rotifer,resulting in miniaturization of zooplankton in aquaculture area. It was concluded that the water quality was in middle pollution level in outlet area,in light pollu-tion level in aquaculture areas,and in clean level in other 4 areas based on biodiversity,indicating that the water quality were in good state except outlet area,and the pond industrial eco-aquaculture system functioned well.