Crustacean aquaculture has been an important and diversifying aquaculture sector that has seen sea changes ever since commercial aquaculture of penaeid shrimp grew leaps and bounds during the late 80s and 90s. The diversification and introduction of species beyond the tiger shrimp (Penaeus monodon) and Kuruma shrimp (Penaeus japonicus) intensified the cultural practices resulting in the emergence of various diseases. Though crab and lobster joined this spectrum of species under aquaculture, health-related problems were more visible and experienced in shrimp aquaculture. Shrimp belong to the decapod group of crustaceans, a major invertebrate class. Naturally, while lacking the specificity of the immune response, they are blessed with a variety of nonspecific defense factors such as the hard shell, regeneration capacity, fast blood clotting, etc. Shrimp and other decapod crustaceans have a well-defined mechanism of clearing bacteria and other invading foreign particles from their hemolymph. Modulator proteins in crustaceans can recognize various cell wall components of bacteria and fungi resulting in enhanced fighting capabilities against the invading pathogen. This mechanism of recognition of cell wall components of bacteria is being used in stimulating the immune responses in shrimp. Vibrio is one of the most important groups of Gram-negative bacteria present in brackish water and seawater environments. They possess an important cell wall component, the lipopolysaccharides (LPS), which have the capabilities of triggering and activating the shrimp immune elicitors. These components can activate both the transglutaminase and the phenoloxidase (PO) pathways of shrimp immune response. Hence, immunostimulation, supported by judicious water quality management, has immense potential in maximizing production from shrimp aquaculture systems.