The ultimate goal of the project is to advance practical diet development for California yellowtail (CY). This is important given the great potential to expand the culture of CY commercially. The specific goals of this project are to (1) develop and validate an open formulation for the CY based on modifications of the existing commercial diet being fed to CY; (2) evaluate the response of CY to a diet with increasing levels of soy protein concentrate, and (3) evaluate the response of CY to a diet with increasing levels of soy oil as a fish oil replacement while keeping other nutritional factors constant.