Relationships between butterflyfish (Chaetodontidae) feeding rates and coral consumption on the Great Barrier Reef

This study explored differences in the feeding rate among 20 species of coral reef butterflyfishes (Chaetodontidae) from Lizard Island, Great Barrier Reef. Feeding rate, measured as bites per minute (b.p.m.), varied between 2.98 ± 0.65 and 12.29 ± 0.27 (mean ± SE) according to species and was positively related to the proportional consumption of coral (r ² = 0.40, n = 20, P < 0.01), independent of phylogeny (standardised independent contrasts r ² = 0.29, n = 19, P < 0.05). All species fed actively throughout the day, with obligate corallivores having a higher feeding rate at all times than either facultative corallivores or non-corallivores. The feeding rate of the obligate corallivores was also highest during the middle of the day. For eight of the species for which data was available, there was a positive correlation between bite rate and competitive dominance (r = 0.71, P < 0.05). Chaetodon ephippium was the only species for which the feeding rate of pairs was higher than for solitary individuals.