Journal article
Contrasting population structures of reef-building corals and their algal symbionts inform adaptive potential across the western Pacific
Current biology, Vol.First online, pp.1-24
20/05/2026
PMID: 42167243
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Abstract
The genetic diversity and connectivity of reef-building coral populations are key to their survival in warming oceans. Yet our understanding of corals' demographic resilience and adaptive potential is complicated by cryptic species diversity, wide geographic distributions, and complex coral-algal symbioses. To address these challenges, we investigated the genetic connectivity and diversity of the broadcast-spawning coral Acropora cf. spathulata and its associated Symbiodiniaceae across 29 reefs spanning the Great Barrier Reef, the Coral Sea, and New Caledonia, using whole-genome sequencing of 1,088 colonies. We identified four genetically distinct coral populations that diverged between 0.27 and 0.65 mya, likely due to geographic isolation across thousands of kilometers. These populations maintained asymmetrical gene flow along major ocean currents despite demographic isolation and sustained large local effective population sizes (∼2,900), supported by a high dispersal range of ∼100 km per generation. In contrast, their Symbiodiniaceae partners varied over finer spatial scales, with five distinct Cladocopium taxa distributed along latitudinal and cross-shore gradients, likely driven by local environmental conditions. These results suggest that high dispersal capacity and large local population size promote demographic resilience within reef systems, while environment-specific symbioses and long-distance gene flow across reef systems support adaptation and evolutionary rescue.
Details
- Title
- Contrasting population structures of reef-building corals and their algal symbionts inform adaptive potential across the western Pacific
- Creators
- Hugo Denis - Sorbonne UniversitéKatharine E Prata - Australian Institute of Marine ScienceHisatake Ishida - The University of QueenslandIva Popovic - Australian Institute of Marine ScienceVéronique J L Mocellin - Australian Institute of Marine ScienceMagali Boussion - University of New CaledoniaIlha Byrne - The University of QueenslandSteven W Purcell - Southern Cross UniversityLine K Bay - Australian Institute of Marine ScienceGaël Lecellier - University of New CaledoniaCheong Xin Chan - The University of QueenslandCynthia Riginos - The University of QueenslandEmily J Howells - Southern Cross UniversityVéronique Berteaux-Lecellier - University of New Caledonia
- Publication Details
- Current biology, Vol.First online, pp.1-24
- Publisher
- Elsevier Inc.
- Grant note
- Work undertaken in Australia was supported by the Reef Restoration and Adaptation Program, funded through a partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation. Work in New Caledonia was supported by CNRS and IRD funding and was part of the WINREEF (Reef Resilient Initiative/ Neo Caledonia Biodiversity Agency funding) and ReCoVer (Pacific Funds) projects.
- Identifiers
- 991013377950802368
- Copyright
- © 2026 The Authors
- Academic Unit
- Faculty of Science and Engineering; National Marine Science Centre
- Language
- English
- Resource Type
- Journal article