Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes
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Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes (Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reefs: present-day reefs that are vulnerable to climate-induced coral bleaching, and reefs with more bleaching-robust coral taxa, thereby simulating the likely future of coral reefs under a warming climate. Fish communities were allowed to establish naturally on the reefs during the summer recruitment period. Climate-robust reefs had lower total species richness of coral-reef fishes than climate-vulnerable reefs, but total fish abundance was not significantly different between reef types (pooled across all species and life-history stages). The nature of aggressive interactions, measured as the number of aggressive chases, varied according to coral composition; on climate-robust reefs, juveniles used the substratum less often to avoid aggression from competitors, and interspecific aggression became relatively more frequent than intraspecific aggression for juveniles of the coral-obligate P. moluccensis. This study highlights the importance of coral composition as a determinant of behaviour and diversity of coral-reef fishes.
KeywordsBenthic composition Habitat degradation Intraspecific and interspecific aggression Species richness Community dynamics
We thank Tessa Hempson, Aaron MacNeil and Karen Chong-Seng for assistance with building the patch reefs and for census data of fish on the patch reefs collected in early December 2013 and late January 2014. We also thank Grace Frank, Alex Vail, Kirsty Nash and staff of Lizard Island Research Station for assistance during fieldwork, and two anonymous reviewers whose comments helped to clarify the interpretation of our results. Funding for this project was provided by the Australian Research Council and James Cook University.
- Barley AJ, Coleman RM (2010) Habitat structure directly affects aggression in convict cichlids Archocentrus nigrofasciatus. Zoology 56:52–56Google Scholar
- Hoegh-Guldberg O (2004) Coral reefs in a century of rapid environmental change. Symbiosis 37:1–31Google Scholar
- Randall JE, Allen GR, Steene RC (1997) Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press, Honolulu, p 557Google Scholar
- Veron JEN, Stafford-Smith M (2000) Corals of the World, volumes 1–3. Australian Institute of Marine Science, TownsvilleGoogle Scholar