Pages: (86-105 )
Abstract
The Silver catfish (Chrysichthys nigrodigitatus) used for this study were bought from the local fisher men at Makoko and Clarias gariepinus juvenile which were purchased from a private fish farm at Iyana Ipaja, Lagos State. The fish samples were cleaned, filleted and placed in a clinical bottle; the morphometric analysis was determined before transporting them in a labelled container to the laboratory for fatty acid composition and determination of heavy metals. Total fatty acid composition in the sampled fish muscle were compared. Saturated fatty acids (SFA) 14.80 and 6.73±0.91, Monounsaturated fatty acids (MUFA) 20.96±3.8 and 47.00±6.52, polyunsaturated (PUFA) 36.30±3.07 and 28.40±4.42 were found in Chrysichthys nigrodigitatus and Clarias gariepinus of total fatty acids respectively, Moderate concentrations of Cd, Cr, Pb, Zn, and Cu were detected in the tissue of Clarias gariepinus which the parameters where lower than WHO limit (0.05) for cadmium and chromium, but Pb was not detected in the sampled Clarias gariepinus in the month of March and April. Zn had a higher concentration than the rest of the heavy metals detected in Clarias gariepinus. The heavy metal concentrations in the tissue of Chrysichthys nigrodigitatus in March April and May were distributed according to the following pattern: Zn > Ni > Cr > Pb > Cd Likewise in Clarias gariepinus with lower concentrated amount compared to Chrysichthys nigrodigitatus. The study of the fatty acids profile of Chrysichthys nigrodigitatus and Clarias gariepinus revealed that they are Bacteria, Biosynthesis, Macromolecules, Medicine, Monomers rich in protein and have low to high fat contents.
Keywords: Catfish, Metallic elements, Fat composition, Makoko, Iyana-ipaja,