Amazonian buriti and pracaxi as potential functional feed additives to improve shrimp immunity and resistance to WSSV

Environmental and nutritional factors are critical in modulating the immune system of Penaeus vannamei, particularly under viral threats such as white spot syndrome virus (WSSV). This study evaluated the effects of two Amazonian plant-based feed additives, buriti (Mauritia flexuosa) and pracaxi (Pentaclethra macroloba) brans, on shrimp immunocompetence, oxidative balance, and resistance to WSSV. Shrimp were fed diets supplemented with 4 % or 8 % of each ingredient. The group receiving 8 % buriti (B8) exhibited the most consistent improvements in immunoparameters, including enhanced phenoloxidase activity, elevated serum protein concentration, and stronger agglutination responses against marine bacterial pathogens. In contrast, pracaxi-supplemented diets negatively affected shrimp performance and survival. Following WSSV challenge, shrimp fed the B8 diet showed a 25 % increase in survival compared to controls. Biochemical analyses revealed increased catalase activity, elevated reduced glutathione levels, and decreased lipid peroxidation, indicating enhanced antioxidant capacity and reduced oxidative stress in the hepatopancreas. Additionally, the expression of immune-related genes (PPAE1, PPAE2, TGII, CAT) and antiviral effectors (Vago4, Vago5, STING) was upregulated, suggesting activation of antimicrobial, redox-sensitive and interferon-like antiviral pathways. No significant changes in midgut bacterial microbiota were observed, the dietary safety of the B8 formulation. These findings demonstrate that dietary inclusion of buriti bran at 8 % emerges as a natural feed additive that enhances WSSV resistance in P. vannamei by promoting immune resilience and oxidative homeostasis. Moreover, its sustainable production and alignment with circular economy principles and the Blue Amazon initiative underscore its potential as a functional feed additive for eco-friendly aquaculture.