作　　者： ; ; (金刚）;

机构地区： 中国科学院水生生物研究所淡水生态与生物技术国家重点实验室

出　　处： 《水生生物学报》 2003年第4期345-351,共7页

摘　　要： 在移栽有沉水植物的网箱和水泥池 ,放养不同规格和密度的河蟹 ,以定量研究河蟹对沉水植物的影响 ,进而探讨草型湖泊河蟹的养殖容量。草型湖泊对河蟹的养殖容量 (或负荷力 )可以定义为对水生植被的生长没有显著影响时的最大的河蟹现存量。通过河蟹放养密度与沉水植物相对生长率的分析 ,获得了不同规格河蟹的养殖容量。当年幼蟹规格较小 (壳宽 18 0± 1 2mm) ,其养殖容量为 2 3ind·m-2 ;二龄幼蟹 (35 0± 3 6mmCW )的养殖容量是0 9ind·m-2 ;较大规格河蟹 (6 0 0± 5 7mmCW)的养殖容量是 0 0 83ind·m-2 。进一步分析得知 ,在草型湖泊中河蟹对沉水植物生长不构成显著影响的最大产量密度为 2 9 2 5kg·hm-2 。 The experiments on Chinese mitten crab (Eriocheir sinensis) stocked in cages and tanks with the transplanted submersed macrophytes were conducted to study effects of the crab sizes and densities on the biomass of different macrophytes, and to investigate the carrying capacity of the crab in macrophytic lakes. The small juvenile mitten crab (CW:7.0±0.6 mm) had little effect on biomass of the four submersed macrophyte species, at the stocking density of 50 to 200 ind·m -2. There were no floating, fragmented leaves or whole macrophytes found during the experiment for small crabs. It was observed that while feeding,these small crabs used their very small and weak claws to grip and tear foods, usually the surface parts of leaves or stems of submersed macrophytes or periphyton on them. The larger mitten crabs (18.0±22 mm CW) had noticeable effects on submersed macrophyte biomass, and the effects were significant at the higher crab stocking densities (≥40 ind·m -2). When the size of the crab became larger (35.0±3.6 mm CW), it had a much stronger effect on macrophyte biomass, in which, with stocking densities not less than 3 ind·m -2, whole V.spiralis with or without roots and its long leaves and the long stems of C. demersum, P. maackianus and M. spicatum were all found floating. Except for M. spicatum, plant biomass decreased sharply due to the largest crabs (60.0±5.7 mm CW) at stocking densities not less than 0.25 ind·m -2, and biomass of M. spicatum decreased significantly at stocking densities not less than 0.5 ind·m -2. While feeding, or searching for food, the largest crabs cut the leaves of V. spiralis from the lower end, and it resulted in floating long leaves or whole macrophyte. In the present paper, the carrying capacity is defined as the maximal standing biomass of the crab in the case that the macrophyte growth is not significantly affected by the crab. The different carrying capacities for the crabs of different sizes were estimated by analyzing the relationship between the crab d

关 键 词： 草型湖泊 河蟹 沉水植物 养殖容量

领　　域： [农业科学] [农业科学]