Abstract
Fish is considered one of the most important sources of animal protein in Egypt due to the extreme need for sources of proteins particularly with the steady increase of the population. In this study about 200 catfish were collected from four different canals ( El Maruttia, El Mansouria, El Ismailia and El Khanater ) of the metropolitan area of Cairo ( Cairo - Giza - Kalyobia) in Egypt and the results of this study were summarized into 12 figures. The results of this study point to the existence of a significant differences in the concentrations of copper, iron, zinc, chromium, nickel, lead, cadmium and mercury in the muscles of catfish among all the groups of the study. In a comparison between all the groups of the study for iron (Fe) levels in muscles of the catfish (males and females) it was found that 100% of the fish in El Maryottia canal have concentrations of iron higher than allowed levels .with regard to the copper (Cu) it was found that its levels in the muscles of fish collected from El Maruttia (males and females) were higher than admissible limits as the following (19.16 , 21.28) µg / g , respectively, while samples from all the other places such as El Mansouria, El Ismailia , El Khanater were contain different concentrations of copper, but within the permissible levels either in males or females .With reference to lead (Pb) it was found in all the muscles of catfish from all canals with rate 100% higher than the permitted levels except for El Khanater its levels in muscles were within the permissible limits, but lead was found in the liver samples of all groups from all canals. For mercury (Hg) it was noticed that the muscles of catfish collected from El Maruttia canal and El Mansouria contain a higher concentrations than the allowed levels. Also the results of this study refer to presence of significant differences in the concentrations of (iron, copper, lead and mercury) in between the liver samples of catfish from different groups of the study.

Key words: Key words: Cat Fish, heavy metals, muscle