Effects of juvenile coral-feeding butterflyfishes on host corals
- 243 Downloads
Corals provide critical settlement habitat for a wide range of coral reef fishes, particularly corallivorous butterflyfishes, which not only settle directly into live corals but also use this coral as an exclusive food source. This study examines the consequences of chronic predation by juvenile coral-feeding butterflyfishes on their specific host corals. Juvenile butterflyfishes had high levels of site fidelity for host corals with 88% (38/43) of small (<30 mm) juveniles of Chaetodon plebeius feeding exclusively from a single host colony. This highly concentrated predation had negative effects on the condition of these colonies, with tissue biomass declining with increasing predation intensity. Declines were consistent across both field observations and a controlled experiment. Coral tissue biomass declined by 26.7, 44.5 and 53.4% in low, medium and high predation intensity treatments. Similarly, a 41.7% difference in coral tissue biomass was observed between colonies that were naturally inhabited by juvenile butterflyfish compared to uninhabited control colonies. Total lipid content of host corals declined by 29–38% across all treatments including controls and was not related to predation intensity; rather, this decline coincided with the mass spawning of corals and the loss of lipid-rich eggs. Although the speed at which lost coral tissue is regenerated and the long-term consequences for growth and reproduction remain unknown, our findings indicate that predation by juvenile butterflyfishes represents a chronic stress to these coral colonies and will have negative energetic consequences for the corals used as settlement habitat.
KeywordsCorallivore Chaetodontidae Settlement Chronic stress Coral condition Tissue biomass
Funding for this project was provided by the ARC CoE for Coral Reef Studies. The authors thank D. McCowan and K. Chong-seng and the staff at LIRS logistical support and field assistance. This paper benefited from helpful comments provided by S. Wilson and two anonymous reviewers.
- Baird AH, Marshall PA, Wolstenholme J (2002) Latitudinal variation in the reproduction of Acropora in the Coral Sea. Proc 9th Int Coral Reef Symp 1:385–389Google Scholar
- Cole AJ, Lawton RJ, Pratchett MS, Wilson SK (2011) Chronic coral consumption by butterflyfishes. Coral Reefs. doi: 10.1007/s00338-010-0674-6
- Holbrook SJ, Schmitt RJ, Brooks AJ (in press) Indirect effects of species interactions on habitat provisioning. Oecologia. doi: 10.1007/s00442-011-1912-5
- Munday PL, Wilson SK (1997) Comparative efficacy of clove oil and other chemicals in anaesthetization of Pomacentrus amboinensis, a coral reef fish. J Fish Biol 51:931–938Google Scholar