Effect of Rationing on Oreochromis niloticus (Linnaeus, 1758) Tilapia Larvae Reared in Happas (Dabou, Ivory Coast)

Effective feeding-rate management remains an important concern in tilapia larval culture in Côte d’Ivoire. This study examined the effects of three daily biomass-based feeding rates on the growth and survival of Oreochromis niloticus larvae reared in happas at the Layo Experimental Aquaculture Station. The 35-day trial was conducted from 10 March to 14 April 2025. A total of 225 larvae, with an initial mean weight of 30.67 ± 7.40 mg and mean length of 12.63 ± 0.57 mm, were distributed among nine 50-L happas, with 25 larvae per happa. Feeding rates of 10%, 20% and 30% of biomass were each tested in triplicate. The larvae received a commercial feed containing 47% protein, distributed three times daily. Ten larvae from each happa were randomly selected, weighed and measured weekly. Survival was recorded, and water physicochemical parameters were monitored. At the end of the trial, the 20% group achieved the highest mean final weight (1,745.33 ± 297.71 mg) and length (45.00 ± 2.50 mm), with 100% survival. Mean final weights were 1,574.15 ± 381.57 mg and 1,712.00 ± 250.70 mg in the 10% and 30% groups, respectively. Differences in survival among treatments were not statistically significant. Under the conditions investigated, feeding at 20% of larval biomass was associated with the most favourable combined growth and survival outcomes. Further assessment during the grow-out phase, including economic evaluation, is warranted.