Lipid and Fatty Acid Composition of Commercially Important Tropical Freshwater Fish Gonads: Guidelines for Specific Broodstock Diet

Fatty acids compositions were analyzed in neutral lipids (NL) and polar lipid (PL) of gonads of Nile tilapia, ayungin and African catfish to elucidate some guesses for the fatty acids requirements for broodstock. The high value detected for both C16:0, C18:1 n-9 in all samples reflects a requirement for energy metabolism during the course of gonad development. The Lower proportion of polyunsaturated fatty acids (PUFA) was found in the NL of all gonads samples compared to PL. The higher percentages of n-3 HUFA in PL with respect to NL, suggests the importance of HUFA in the reproductive processes. In PL and NL, arachidonic acid (ARA) was the most abundant n-6 PUFA (ranged from 2.59 to 11.33% and from 0.16 to 3.19%, respectively). A relatively higher particularly eicosapentaenoic acid (EPA)/ docosahexaenoic acid (DHA) ratio was obtained in both NL and PL. All wild species studied are characterized by high ARA/EPA ratio in PL ranged from 1.72 to 5.47. Therefore, it is necessary to take into consideration not only the individual levels of HUFA but also the correct ratio among them (ARA/EPA/ DHA) through controlling LA and LNA level and ratio in the diets of tropical freshwater broodstocks.