Effects of Dietary Supplementation with Kappaphycus alvarezii and Spirulina platensis on Growth Performance, Immunity, and Disease Resistance of Penaeus vannamei Challenged with Vibrio parahaemolyticus

This study investigated the effects of dietary supplementation with Spirulina platensis and Kappaphycus alvarezii on the growth performance, body composition, immune response, and disease resistance of Penaeus vannamei reared in HDPE-lined pond using hapas. Experimental diets containing inclusion levels of 10% S. platensis (T2) and 5% K. alvarezii (T1) and control diet (without any inclusion) were evaluated over a 100 day feeding trial. Shrimp fed an S. platensis–based diet showed significantly higher final body weight (23.15 ± 0.18 g), weight gain, specific growth rate, and protein efficiency ratio, along with the lowest feed conversion ratio (1.30 ± 0.02), compared to the control group (P < 0.05). Whole-body protein, lipid, and ash contents were significantly enhanced in T1 and T2. Following Vibrio parahaemolyticus challenge, shrimp fed algal-supplemented diets showed improved survival and reduced mortality than the control diet. Immune parameters, including total haemocyte count, prophenoloxidase, respiratory burst, superoxide dismutase, and catalase activities, were significantly elevated in T1 and T2 compared to the control. These findings demonstrate that dietary inclusion of S. platensis and K. alvarezii enhances growth, immunity, and disease resistance in P. vannamei, supporting their potential as functional feed additives for sustainable shrimp aquaculture.