Comparative Analysis of the Nutritional Composition of Three Commonly Consumed Fish Species in Lagos Markets, South West Nigeria

Fish constitutes a primary source of animal protein for a significant proportion of the Nigerian population, particularly in coastal communities in South West Nigeria. Lagos State, with its extensive Atlantic coastline and numerous inland water bodies, supports a thriving fish trade. This study conducted a comparative nutritional analysis of three commonly consumed fish species sold in Lagos markets: Clarias gariepinus (catfish), Scomber scombrus (mackerel), and Tilapia zillii (tilapia). Fresh samples of each species were purchased from Makoko Fish Market, Mushin Market, and Mile 12 Market. Proximate composition, amino acid profile, fatty acid composition, and mineral content were determined following standard Association of Official Analytical Chemists procedures. Results showed that Clarias gariepinus had the highest crude protein content (21.8 percent) and essential amino acid index among the three species. Scomber scombrus demonstrated the highest total fat content (12.4 percent) and the most favourable omega-3 to omega-6 fatty acid ratio, making it particularly valuable for cardiovascular health. Tilapia zillii showed moderate nutrient values with the highest calcium content (78.3 mg per 100g). All three species were found to be excellent sources of complete protein. The study provides consumers and public health practitioners with comparative data to support informed dietary choices in Lagos State. Keywords: fish, proximate composition, amino acids, omega-3, Lagos.