Department of Marine Sciences, University of Lagos, Lagos State, Nigeria
Ayoola, S.O., Department of Marine Sciences, University of Lagos, Lagos State, Nigeria; Dansu, F.M., Department of Marine Sciences, University of Lagos, Lagos State, Nigeria
Human activities have led to the accumulation of toxic metals in the aquatic environment. Heavy metals are serious pollutant in the aquatic environment because of their environmental persistence and ability to be accumulated and cause deleterious impact on aquatic organism. This study was carried out to investigated the levels of some selected heavy metals (Cd, Cr, Cu, Fe, Pb and Zn) in two fish species: Chrysicthys nigrodigitatus and Pythonichthys macrurus obtained from Makoko area of the Lagos lagoon between the months of July-September, 2012 and also to determined the effects of these metals on haematological parameters and enzymes activity of the fish species. The mean concentration of heavy metals in mg/l obtained for C. nigrodigitatus were Cd (ND), Cr (0.010±0.001), Cu (0.036±0.022), Fe (0.580±0.137), Pb (0.001±0.001), Zn (0.218±0.346) and P. macrurus; Cd (0.001±0.002), Cr (0.005±0.005), Cu (0.046±0.066), Fe (0.359±0.270), Pb (ND), Zn (0.228±0.376) were below the standards of WHO/FAO/FEPA permissible limit. The mean level of the enzymes recorded in (IU/L) for C. nigrodigitatus were Aspartate aminotransferase AST (71.95 ± 26.76), Alanine Aminotransaminase ALT (22.367±12.83), Alkaline phosphatase ALP (164.61 ± 26.65) and for P. macrurus were AST (115.82±41.04), ALT (37.79± 25.16) and ALP (59.80±21.99) respectively. Statistical significance difference (P <0.05) occurred in serum ALP between the two fish species. There was no statistically significant difference (P>0.05) recorded in all haematological parameters, the values revealed a high Haemoglobin and PCV concentration for both fishes. Results for C. nigrodigitatus were Hb (12.34 ± 2.15g/dl), PCV (37.00±6.45%), RBC (3.57± 0.92106 mm-3), WBC (136.20±59.06104mm-3), MCV (108.06±28.46FL), MCH (35.99 ±9.45Pg), MCHC (33.32 ± 0.03g/l), Neutrophils (35.33±8.76%), Lymphocytes (64.67±8.76 %) and P.macrurus values were Hb (13.84 ±2.65g/dl), PCV (41.50± 7.94%) RBC (4.18±1.04 106mm-3), WBC (115.87 ± 28.04 104mm-3), MCV (101.37± 16.92FL), MCH (33.86±5.62Pg), MCHC (38.87±13.59 g/l), Neutrophils (39.00± 13.87%) and Lymphocytes 60.67±13.60 (%). Deductions from this study revealed an alteration in the haematological parameters and enzymes activity of C. nigrodigitatus and P.macrurus. The result indicated that the concentrations of these heavy metals fall within their respective acceptable permissible limits recommended by the WHO/FAO/FEPA. Hence the consumption of these fish species may not pose any threat to human health. However periodic monitoring of these metals in the fish and water is highly essential to public health due to bioaccumulation. © IDOSI Publications, 2014.