Quantification and Characterization of Omega-3 Fatty Acids in FishTissues of Congeneric Species, Sardinella maderensis and Sardinella aurita(Clupeidae, Clupeiformes) in the Mauritanian Coast

Introduction: The study focused on measuring omega-3 levels in the tissues of two fish species, Sardinella maderensis and Sardinella aurita, and examining the influence of size and weight on the concentration of fatty acids, particularly omega-3 types such as docosahexaenoic acid (DHA, C22:6n-3) and eicosapentaenoic acid (EPA, C20:5n-3). Methods: Fatty acids were quantified using gas chromatography coupled with flame ionization detection (GC-FID), and the quantification was achieved after oil extraction using the Bligh and Dyer method. Results: The results show that in Sardinella aurita, there is a significant correlation between the percentage of lipids, DHA, and EPA according to weight (percentage of lipids (r = 0.537; p = 0.031), DHA percentage (r = 0.664; p = 0.023), and EPA percentage (r = 0.635; p = 0.025). For Sardinella maderensis, these correlations are also present but less marked (percentage of lipids: (r = 0,517; p = 0.046), DHA percentage (r = 0.504; p = 0.046), and EPA percentage (r = 0.517; p = 0.041)). Size has a strong correlation with the percentage of lipids in Sardinella aurita (r = 0.507; p = 0.018), while this correlation is negligible in Sardinella maderensis (r = 0.06; p = 0.052). Finally, the correlation between size and DHA/EPA is moderate in both species. Discussion: The study provided a better understanding of the relationship between weight and omega-3 content in the muscles of Sardinella aurita and Sardinella maderensis along the Atlantic coast of Mauritania. Conclusion: These results provide a starting point for identifying and quantifying omega-3 in Sardinella aurita and Sardinella maderensis. This increases the value of these products and can also assist exporters in commercialization and marketing.