Abstract
Nile tilapia (Oreochromis niloticus) weighing 51.66 +/- 2.42 g were exposed to 0%, 20%, 40%, and 60% of LC50 to either lead nitrate (Pb(NO3)(2)) or copper sulfate (CuSO4) for 30 days. The Pb(NO3)(2) and CuSO4 concentrations employed in the treatments of this study were 8.8, 17.6, and 26.4 mg/L and 2.57, 5.14, and 7.71 mg/l, respectively, and multiple hematological variables were evaluated. The red blood cell (RBC) count for the control group was 2.41 +/- 0.13 while those of the treatment groups exposed to 8.8, 17.6, and 26.4 mg/L of Pb(NO3)(2) were 2.21 +/- 0.10, 1.94 +/- 0.16, and 1.36 +/- 0.10 x 10(6)/mu l, respectively, at the end of the study. Similarly, the hemoglobin (Hb), hematocrit (Hct), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), and platelet (PLT) levels significantly decreased as the Pb(NO3)(2) concentration increased (p < 0.05), while white blood cell (WBC) and mean cell volume (MCV) levels significantly increased. However, results of fish exposed to CuSO4, showed decrease in the levels of RBC, Hb, Hct, WBC, and PLT when the concentration of CuSO4 increased, while the MCHC, MCH, and MCV levels significantly increased.