Assimilation and Excretion of Copper Contained in Food by Soil Collembolan (Folsomia candida)
土壤跳虫(Folsomia candida)对食物中铜污染物的吸收和排泄

Accumulation,transfer and transport of heavy metals in organisms have attracted increasing attention recently.As an important species in soil ecosystem,it is of great concern to investigate the process and mechanism of uptake,accumulation and excretion of heavy metals by collembolan.The study on the assimilation-excretion efficiency of copper by Folsomia candida（Collembola） was carried out.It is found that Cu content in F.candida increased significantly with the extension of exposure time(r2 = 0.8878,F1,5 = 29.59,P <0.01),whereas Cu content in F.candida decreased significantly with the extension of excretion time(r2 = 0.7836,F1,3 = 7.13,P <0.01)。Moreover,the assimilation-excretion budget results showed that only a small amount of Cu entered into F.candida body.The minor part was assimilated by F.candida tissues,the major part might be eliminated out of F.candida through exuviation of midgut cells and oviposition.It is concluded that exuviation and oviposition were important pathways to excrete Cu by F.candida.The low assimilation efficiency（8.13%） and high excretion efficiency（57.3%） of copper suggested the relative high tolerance of F.candida to copper pollution.