ABSTRACT
Calcium, copper, magnesium, manganese, iron, and zinc were assessed in water, sediment and some organs [exoskeleton, gills, and digestive gland] of crayfish, Procainharus clarkii, from four sites [I: Gezyrat El-Warrak, II: Manial Sheeha, III: Al-Hawamdia and IV: Helwan] along the River Nile at Greater Cairo, Egypt. Samples of water, sediment and P. clarkii organs were analyzed by atomic absorption spectrophotometer. The results show that the highest concentrations of metals in different sites [I-IV] of the Nile water were in the following order: site IV>III>I>II for Ca and Mg, site II>IV>III>I for Fe, Mn and Zn, and site II>III>IV>I for Cu, respectively. Meanwhile, the highest concentrations of the studied metals in the Nile sediment were in the following order: site IV>I>II> III for Ca, site II>III>IV>I for Fe, site I>II>III>IV for Cu, site I>II>IV>III for Zn, site IV>III>I>II for Mn and site IV>III>II>I for Mg, respectively. The bioaccumulation factor [BCF] of these metals in the exoskeleton and digestive gland of P. clarkii revealed the following order: Fe> Mn > Cu > Mg> Zn > Ca. However, the order of accumulation of these metals in the gills was Fe>Cu > Mn > Mg> Ca > Zn. These results indicate that the analysis of such metals in various body parts of P. clurkii is useful as a bioindicator for pollution in the freshwater system.