Outline metal concentration and Nutritional traits of six fish species from the Oba reservoir in Ogbomoso, Benin-Nigeria

Abstract

The nutritional qualities and concentration of trace metals (Pb, Fe, Cu, Zn, and Cd) in six fishes
(Hemichromis fasciatus, Siluranodon auritus, Sarotherodon galileaus, Tilapia zilli, Chrysichthys
nigrodigitatus, and Hepsetus odoe) obtained from Oba reservoir in Ogbomoso, Nigeria were evaluated.
The value ranges of 55.95 to 68.80, 16.91 to 26.18, 5.46 to 18.18, 0.51 to 9.05, 7.67 to 10.14 and 0.97 to
1.41% were obtained for moisture, protein, fat, carbohydrate, ash and fibre contents, respectively.
Highest protein and fat contents were obtained from H. odoe. The trace metals in fishes were found at
various concentrations (P≤0.05). High levels of essential metals; Fe, Cu and Zn, were found in the
fishes. The concentrations of Pb and Cd were also high in the fishes, but not detected in the water
sample from the reservoir. A positive correlation was observed between fat and fibre (P≤0.01) as well as
Zn and Pb (P≤0.05) while fat and iron were negatively correlated. The results show that the fishes
evaluated are rich in essential nutrients. However, prior exposure of the fishes to pollutants was not
unlikely as shown by Pb and Cd levels. There is the need to initiate further study to identify sources of
these pollutants and their effects on biota from Oba reservoir.