Evaluación de moringa Moringa oleifera (Lam.,1783) como aditivo dietético para el cultivo de semillas de ostra perlera, Pteria sterna (Gould,1851), en ambiente controlado

Abstract

Microalgae are the natural diet par excellence during the hatchery mollusks seed nursery, but they can be supplemented with artificial diets to increase production efficiency and reduce production costs. The effects of the use of moringa flour (Moringa oleifera) and cornstarch (maicena®) as dietary additives supplied as a function of dry weight (%) of tissues in pearl oyster spat Pteria sterna, were evaluated for one month. Cornstarch provides energy mainly in the form of carbohydrates, while moringa provides essential fatty acids and amino acids. The experimental design included six diets in triplicate: D1 (Mix 50:50 Chaetoceros gracilis and Tetraselmis suecica = MM), D2 (MM + 5% cornstarch), D3 (MM + 5% moringa), D4 (MM + 2.5 % cornstarch + 2.5% moringa), D5 (5% moringa) and D6 (5% cornstarch), considering 42 individuals for experimental unit (aquarium). Spat growth in weight, size and survival percentage was recorded every fortnight. At the end of the laboratory bioassay (phase 1), the seeds were transferred to a cultivation farm suspended in the sea (phase 2) for 50 days, to accumulate a total of 80 days. As the main and relevant result, diet 4 produced the highest significant increase in dry tissue mass and dry mass of the shell, surpassing the natural diet which are microalgae (D1). Survival of oysters fed D5 progressively decreased until reaching 0% at the end of phase 1 (30 days), ruling out moringa meal as a useful mono-diet. The highest average values were obtained with D4, in terms of survival (97.6%), dry tissue mass and dry shell mass, which suggests a synergistic and positive effect of its components. The superior efficiency of diet 4 was confirmed by obtaining more competent seeds, once transferred to a suspended culture system in the sea. The results of this research allow us to assume that diet 4 (microalgae + 2.5% cornstarch + 2.5% moringa), has potential productive application for the nursery of P. sterna seeds, and possibly other species of bivalve mollusks of commercial interest.