Effects of dietary Pb at different levels on growth performance and Pb residues in tissues of tilapia (Oreochromis niloticus).

Four hundred eighty tilapia were randomly divided into four treatments exposed to 0,100,400 and 800 μg Pb·g-1 respectively in diet,and effects of dietary Pb on growth performance and Pb residues in tissues of tilapia were investigated.The results show that no significant differences in growth performance were observed between control and Pb-exposed treatment(P0.05) after 45-day trial.Pb residues in tissues of tilapia increased with the increase of dietary Pb concentrations and the prolongation of exposure period.Moreover,Pb accumulated in sampled tissues was the order as follows:intestine posterior kidney bone stomach liver gill spleen testis muscle brain.The results above reveal that tilapia has strong resistance to dietary Pb stress.Pb residues in kidney and bone exhibited high Pb burdens may be used as surrogate indicators of Pb pollution,and Pb residues in intestine and stomach can indicate specially Pb contamination in diet.