Preliminary Study on Accumulation and Depuration of Copper, Zinc, and Lead in Tilapia (Oreochromis mossambicus) under Laboratory Conditions

Abstract: Tilapia (Oreochromis mossambicus) was studied for the uptake and elimination of single metals namely Copper (Cu), Zinc (Zn) and Lead (Pb) under laboratory conditions. Tilapia was acclimatised at 25 ± 2°C for 4 days. The dissolved oxygen and pH of water samples were maintained at 6 - 7 mg/L and 7.6 ±0.1 respectively. The exposures to Cu (0, 5, 10, 15 and 20 mg/1), Zn (0, 10, 15, 20 and 25 mg/L) and Pb (0, 1, 2, 3 and 4 mg/L) over a period of 4 days were followed by 4 days of depuration. The accumulation and depuration patterns of Cu and Zn were not apparent and statistical analysis (t-test) did not show any significant difference (p 0.05) for both phases. The results indicate that tilapia can be used as a biomonitor for Pb as there was significant difference (p 0.05) between accumulation and depuration of Pb, particularly for higher exposures (3 mg/L and 4 mg/L Pb).