We study an abundant 'herbivorous' fish on Pacific coral reefs: the striated surgeonfish, Ctenochaetus striatus. Understanding its role in the reef ecosystem, and what it eats, is critical given its decline on some reefs. This charismatic fish helps keep the reef 'clean' which facilitates coral settlement, but we don't know exactly how. We aim to combine genetic barcoding of feces with behavioral studies to provide some answers about its diet.