养鳗池塘生态系统中矿物元素及其影响因素

The mineral elements in Japanese eel(Anguill japonica) pond ecosystem and the influence factors

对比分析了6口处于不同养殖阶段的日本鳗鲡(Anguill japonica)池塘水体、水源、底泥及饲料中的矿物元素,探讨了池塘生态系统中矿物元素的主要影响因素和生产管理对策,结果表明:1)养鳗池塘水体矿物元素与所处养殖阶段投入饲料的品种相关,底泥中矿物元素部分在养殖过程中积累而来;2)主成分分析结果表明钙、镁、铝元素是池塘水体、底泥样本聚类的主因子,而不同养殖阶段投入的黑仔鳗料、幼鳗料和成鳗料三种饲料中铝、镁、钙三种矿物元素含量差异较大,间接证明了养殖过程中投入的饲料品种对池塘生态系统中矿物元素具有较大影响;3)水源和6口池塘水体样本都未检测到锰元素,水源样本中磷元素也未检测到,说明在养殖初始阶段需要补充磷元素,整个养殖过程中需要补充锰元素,以促进藻类繁殖生长;4)换水和底泥扰动等日常管理工作可使池塘生态系统中矿物元素含量发生变化,底泥扰动促进了泥与水之间矿物营养交换,其中磷、铁、钙变化显著(P<0.05),底泥扰动应成为鳗鱼健康养殖中一个重要的日常管理措施。

The mineral compositions of the pond water,water supply and bottom mud from 6 ponds for eel in different culture stage,as well as the minerals of the feeds were comparatively analyzed to study the main influential factors for the minerals in the pond system and the management measures.The results showed：1） the minerals composition of pond water was associated with the feeds in the culture stage.Parts of the minerals in bottom mud were accumulated in the course of culture.2） Calcium,magnesium and aluminum were the main factors for hierarchical cluster of water body samples and bottom mud samples,moreover,the Ca,Mg and Al contents of three eel feeds（the black eel feed,the elver feed and the adult feed） used in different stages were significantly different,which indirectly demonstrated that the feed type had relatively higher influence on the minerals in pond ecosystem.3） No manganese was detected in all 6 pond water bodies,and no phosphorus was detected in all water supplies,which indicated that phosphorus needed to be replenished in the primary culture stage,and manganese needed to be replenished in the whole culture course to enhance the reproduction and growth of algae.4） The daily management including changing water and disturbing bottom mud can alter the contents of the minerals in the pond ecosystem.Bottom mud disturbing promoted the minerals exchange between mud and water.The content of phosphorus,iron and calcium changed significantly（P0.05）.Therefore,bottom mud disturbing should be an important daily management measure in the healthy culture of eel.