In order to provide the best possible nutrition to developing marine larvae, we must understand both the nutritional needs of the larvae at all developmental stages as well as the capacity of a larva to digest food with a very simple digestive system. Our group is working both to understand the physiological responses of larval marine fish to the act of feeding and the limitations of the larvae to utilize complex feed ingredients. Only by understanding these factors can we improve the diets currently used by commercial larviculturists and thereby help reduce the single largest roadblock to increased aquaculture production in the United States.