Activity budget of the princess parrotfish (Scarus taeniopterus): a comparison between daylight and sunset periods


Most animals are active either during the day, night, or twilight, and transition periods between these times exhibit interesting behavior. Actions may be related to avoiding predators, seeking shelter, defending territory, feeding, or other interests. Herbivorous fishes on coral reefs, such as parrotfishes, forage constantly throughout daylight periods due to inefficient feeding and reliance on light. At sunset, parrotfishes seek cover under which to rest at night, to conserve energy and avoid predation. To do so, parrotfish decrease feeding and increasing migration and aggression to do so. This study compared how initial phase (IP) and terminal phase (TP) princess parrotfish (Scarus taeniopterus) allocate time between daylight and sunset periods, specifically regarding time spent feeding and being aggressive. Observations were performed using SCUBA at Yellow Sub dive site on Bonaire, Dutch Caribbean. Individuals of S. taeniopterus were followed for 1 min (to allow for acclimatization), followed by 5 min of behavioral observation. Percent time spent on each behavior was calculated and averaged across each category (e.g. IP, daylight), and mean percent time spent feeding and being aggressive were tested using a two- way analysis of variance (ANOVA), with phase and time of day as factors. Both IP and TP fish had a higher mean percent time feeding and a lower mean percent time being aggressive in the morning than at sunset, and time of day and phase were both significant factors affecting variation in both behaviors. The results of this study give insight into the adaptations parrotfish have developed to increase survival. 

Back to search results