Zooplankton are an excellent option for aquaculture nutrition due to their high nutritional value. The water flea Daphnia magna stands out for its high protein and fatty acid content. Among the microalgae that produce the highest quantities of astaxanthin is Haematococcus pluvialis. This pigment is renowned for its antioxidant and immunostimulant properties. Thus, combining the water flea with this microalga yields a potential nutraceutical food source. For this reason, this study aimed to evaluate the influence of supplementing the diet of pacific white shrimp Litopenaeus vannamei post-larvae with D. magna meal enriched with H. pluvialis (DHP) on shrimp immunity compared to a commercial supplement (CS), followed by a control treatment with only commercial feed (C). Hematological analysis, survival rate, total carotenoids, and astaxanthin were assessed at the end of 33 days culture in a synbiotic system. SPF (shrimp pathogeny free) post-larvae (PL15) of L. vannamei with an average weight of 0.005 ± 0.001 g were acquired from commercial hatcheries and stocked at a density of 3000 shrimps m-3. Total hemocytes count (THC), survival rate, total carotenoids, and astaxanthin were higher in DHP (Fig. 1). The mean THC found for treatments C, DHP, and CS were, respectively, 8.18 ± 2.22; 13.96 ± 1.48; and 11.71 ± 0.78 x 106 cells mL-1. Thus, it was shown that the addition of water flea meal improved the immune system, total carotenoids, and astaxanthin, which are biomolecules with immunostimulant properties. Our findings contribute to expanding the possibilities of alternative protein sources that have the potential to promote the health of aquatic organisms, especially in shrimp production.