Asian Journal of Fisheries and Aquatic Research

Fish oil is the primary dietary lipid source for fish. However, its high cost and limited availability present challenges for aquaculture. Using plant-based oils as an alternative to fish oil could represent a sustainable development path for aquaculture. This study aimed to evaluate the effects of Neocarya macrophylla oil on the fertility of Nile tilapia (Oreochromis niloticus) broodstock. Three isoproteic and isolipidic diets were formulated: a control diet without N. macrophylla oil (R1), and two diets containing 3% (R2) and 6% (R3) N. macrophylla oil. One hundred and eight (108) Nile tilapia broodstock with an average weight of 77.88 g were distributed into nine fiberglass tanks at a density of 9 females and 3 males (sex ratio 3:1) per tank. The broodstock were fed in triplicate with the designated diets twice a day at 9:00 a.m. and 4:00 p.m. at 2% of their biomass for 84 days. Control fishing was performed every 21 days to carry out biometric measurements and evaluate fertility and growth. At the end of the experiment, the fish were dissected and their liver and gonads were weighed. Growth, reproduction parameters, and the length-weight relationship were assessed. Statistical analysis of the growth parameters showed no significant differences between the three diets in terms of weight and length gain. Likewise, no significant differences were found in the gonadosomatic and hepatosomatic indices.Statistical analysis of larval production data revealed that the control diet (R1) was significantly higher (p<0.05) from the 3% and 6% Neocarya oil diets during the fourth control. Thus, incorporating 6% Neocarya macrophylla oil into fish feed results in higher larval production compared to the 3% diet.Regarding reproduction, individuals fed diet R3 produced the highest number of fry (11,977), followed by those fed diet R2 (10,758 fry), and finally diet R1 (8,893 fry). The results indicate that incorporating Neocarya macrophylla oil improves the fertility of Oreochromis niloticus, especially during the fourth control, when only fish fed diets R2 and R3 with Neocarya oil reproduced. The gonadosomatic index ranged from 0.017 to 0.020, the hepatosomatic index ranged from 0.0013 to 0.016. There were no statistically significant differences were found for either index between the diets. Additionally, for the length-weight relationship, tilapia fed diets R1 and R2 had allometric coefficients below 3 (negative allometry), while those fed diet R3 had a coefficient above 3 (positive allometry). This study demonstrated that the incorporation of Neocarya macrophylla oil had a positive effect on the fertility of Oreochromis niloticus.