Abstract
Inter-module physiological integration of colonial organisms can facilitate colony-wide coordinated responses to stimuli that strengthen colony fitness and stress resistance. In scleractinian corals, whose colonial integration ranges from isolated polyps to a seamless continuum of polyp structures and functions, this coordination improves re sponses to injury, predation, disease, and stress and may be one of the indications of an evolutionary origin of Symbiodinium symbiosis. However, observations of species-specific coral bleaching patterns suggest that highly integrated coral colonies may be more susceptible to thermal stress, and support the hypothesis that communication pathways between highly integrated polyps facilitate the dissemination of toxic byproducts created during the bleaching response. Here we reassess this hypothesis by parameterizing an integration index using 7 skeletal features that have been historically employed to infer physiological integration. We examine the relationship between this index and bleaching response across a phylogeny of 88 diverse coral species. Correcting for phylogenetic relationships among species in the analyses reveals significant patterns among species characters that could otherwise be obscured in simple crossspecies comparisons using standard statistics, whose assumptions of independence are violated by the shared evolutionary history among species. Similar to the observed benefits of in creased coloniality for other types of stressors, the results indicate a sig - nificantly reduced bleaching response among coral species with highly integrated colonies.
Original language | English (US) |
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Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | Marine Ecology Progress Series |
Volume | 586 |
DOIs | |
State | Published - Jan 11 2018 |
Funding
Acknowledgements. We thank R. Bieler and J. Gerber of the Field Museum of Natural History for expertise and access to the FMNH museum collections and S. Cairns and T. Coffer of the National Museum of Natural History for expertise and access to the NMNH museum collections. Special thanks to D. Huang for providing us with the tree files for his comprehensive phylogeny of corals. This research was supported by the U.S. National Science Foundation (EFRI-1240416 and CBET-1249311) and U.S. National Institutes of Health (EB 003682). Additional funding came from 108 contributors to a crowdfunding campaign, and the Coral Reefs Challenge Grant, via Experiment.com.
Keywords
- Colony form
- Colony integration
- Coral bleaching
- Phylogenetically corrected analysis
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science
- Ecology