复合养殖系统中浮游动物种类丰度及其影响因素

利用人工湿地和养殖塘构建了复合养殖系统,通过设置不同塘间水质差异,调查了斑点叉尾鮰鱼鱼种培育段和成鱼养殖段不同梯度下的浮游动物种类丰度,并探讨了种类丰度与环境因子的关系.结果表明,2养殖阶段的循环塘中,轮虫的种类丰度随养殖密度的增加而升高,浮游甲壳动物随养殖密度的增加而降低.成鱼养殖阶段对照塘中轮虫的种类丰度高于循环塘P1、P2;枝角类和桡足类的丰度则低于P1、P2;高养殖密度塘P3中,3种形态浮游动物种类丰度均低于对照塘.15种环境因子的主成分分析以及种类丰度与环境因子的冗余度分析结果表明,影响浮游动物种类丰度的主要环境因素为水体的营养状态,水体的物理特征对种类丰度的影响较小.

Zooplankton species richness and impact factors in a compound aquaculture system

A compound aquaculture system, consisted of constructed wetland and culture ponds, was used to rear Ictalurus punctatus. Differences in water quality in the recirculating ponds was obtained by setting different stocking densities. The whole process of fish rearing was separated into two successive stages: juvenile and adult. Zooplankton species richness and water quality parameters were investigated during the two stages. Species richness of Rotifera increased with the increasing stocking densities, while species richness of Cladocera and Copepoda decreased with the increasing densities in the recirculating ponds. Among the adult stage, species richness of Rotifera in the control was higher than those in pond P1 and P2, which was adverse to both Cladocera and Copepoda, while species richness of the three types of zooplankton were all higher in the control than in pond P3. PCA and RDA analysis unraveled that zooplankton species richness depended on trophic status of water body strongly, while weakly on physical characterizations of the water quality.