The animal protein industry has exponentially grown, and intensive production practices cause unavoidable stress to the animals as a result of confinement, transport and handling. Stress generates a physiological condition characterized by suppressed immunity, and consequently, higher disease susceptibility. Yeast Beta Glucan in Aquaculture In aquaculture, in particular, fish are not easily observed by the stock person, and disease outbreaks are often overlooked. Therefore, novel ways to boost the immune response of fish are needed. One natural option that is highly effective is the use of beta glucan because they are considered modifiers of biological response due to their immunomodulatory