Buskey 9314036 This study will examine the effects of food quantity and quality on the growth, feeding and bioluminescence of several species of Protoperidinium. Selective feeding of these pallium, feeding dinoflagellates (which capture large food particles extracellualarly) and the role of sensory perception in this selection process will also be examined. In addition, the study will determine the abundance of heterotrophic dinoflagellates in the western Gulf of Mexico, and examine the relationship between growth rate and bioluminescence capacity for field collected Protoperidinium incubated at ambient food concentrations. ***