Litopenaeus vannamei, a highly adaptable shrimp species known for its growth, thrives in environmental conditions with proper water quality. However, salinity stress poses a significant challenge, compromising shrimp survival and growth. To optimize shrimp feed, the inclusion of alginate and Spirulina sp. offers benefits such as enhanced growth and resistance to environmental stress. This research aims to assess the impact of adding Spirulina sp., alginate, and their combination on the survival rate, resistance to the salinity shock test, and growth of L. vannamei. In this study, a completely randomized design (CRD) method with nine different feed doses was used. The treatments included control, supplementation of Alg 1 (alginate 1 g/kg feed), Alg 3 (alginate 3 g/kg feed), Alg 5 (alginate 5 g/kg feed), Sp 3 (spirulina 3 mg/kg feed), Sp 6 (spirulina 6 mg/kg feed), Sp 9 (spirulina 9 mg/kg feed), AS 1+1 (alginate 1 g/kg feed + spirulina 1 mg/kg feed), AS 2+3 (alginate 2 g/kg feed + spirulina 3 mg/kg feed), and AS 3+5 (alginate 3 g/kg feed + spirulina 5 mg/kg feed). The supplementation of feed was given during the fourteen-day rearing period. The results of the study show that the supplementation of Sp 9 (spirulina 9 mg/kg feed) led to a significant growth (α = 0.05). All treatments supplemented with alginate and/or Spirulina sp. water extract had a significant effect (α = 0.05) on the resistance to the salinity shock test. The different treatments in L. vannamei feed supplementation significantly influenced (α = 0.05) shrimp survival. Polysaccharides and antioxidant properties in alginate and Spirulina sp. have an important role in increasing the growth and resistance to salinity shock of L. vannamei.
