USE OF Spirulina IN SHRIMP (penaeus japonicus) DIET

Spirulina is a unicellular algae with good nutritional value. Its efficiency has been shown in Artemia salina and penaeid shrimp diets. To investigate the origin of this good nutritional value in shrimp, experiments were carried out on Penaeus japonicus juveniles. Pelleted diets containing various proportions of Spirulina from 0 to 8% were fed to shrimp. Good growth, survival and pigmentation were obtained with the diet containing 8% Spirulina. When replacing Spirulina completely by another single-cell ingredient source, lactic yeast, shrimp pigmentation was markedly reduced. Otherwise, growth performances were nearly similar. To identify the active fraction of Spirulina powder, an extraction was performed to separate two fractions, the lipidic and the lipid-free. Preliminary growth results of shrimp fed diets containing these extracted fractions showed that the active fraction of Spirulina was more likely found within the lipid-free fraction, rather than the lipidic fraction. Even though Spirulina can contribute positively to formulation of shrimp diets, it is too expensive (within the French economic context) to be incorporated at high percentage. But a substitution of lactic yeast for Spirulina is feasible as far as shrimp growth and survival are concerned.