A total of 374 striped parrotfish (Scarus croicensis) were tagged from the reefs surroundihg Isla Pico Feo on the Caribbean coast of Panama. Many of these fish were followed individually in the field for up to 3 months. Three different behavioral categories were recognized: stationary, territorial, and foraging. Fish tend to aggregate in foraging groups in a particular pattern relative to reef structure and have a predictable set of associated species. Transfer experiments showed that striped parrotfish have strong ties to a home reef. Striped parrotfish migrate diurnally from shallow—water feeding areas to deeper nocturnal resting areas along constant pathways. Direct counts of fish on migration pathways provided information on the structure and size of the striped parrotfish population at Pico Feo. The numbers of male striped parrotfish may regulate the phenomenon of sex reversal in the scarids.