Population genetic differentiation of the ubiquitous brooding coral Pocillopora acuta along Phuket Island reefs in the Andaman Sea, Thailand

BMC Ecology and Evolution

Research

Christoph Held¹  Frank Melzner²  Marlene Wall³  Andrea L. Schmidt⁴  Anna Fiesinger⁵  Thorsten B. H. Reusch⁶  Lalita Putchim⁷ 

[1] Alfred-Wegener-Institut, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Research Unit Experimental Ecology - Benthic Ecology, Wischhofstraße 1-3, 24148, Kiel, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Research Unit Experimental Ecology - Benthic Ecology, Wischhofstraße 1-3, 24148, Kiel, Germany;Alfred-Wegener-Institut, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Research Unit Experimental Ecology - Benthic Ecology, Wischhofstraße 1-3, 24148, Kiel, Germany;Cooperative Institute for Marine and Atmospheric Research, University of Hawai‘i, 96822, Honolulu, HI, USA;GEOMAR Helmholtz Centre for Ocean Research Kiel, Research Unit Experimental Ecology - Benthic Ecology, Wischhofstraße 1-3, 24148, Kiel, Germany;Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Research Unit Marine Evolutionary Ecoloy, Wischhofstraße 1-3, 24148, Kiel, Germany;Phuket Marine Biological Centre, Wichit, 83000, Phuket, Mueang Phukt District, Thailand;

关键词: Population genetics;    Microsatellites;    Pocillopora;    Indian Ocean;    Bleaching;   

DOI  :  10.1186/s12862-023-02153-7

 received in 2023-03-16, accepted in 2023-08-17,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe widespread Indo-Pacific coral species Pocillopora acuta Lamarck, 1816 displays varying levels of asexual versus sexual reproduction, with strong repercussions on genetic diversity, connectivity and genetic structuring within and among populations. For many geographic regions, baseline information on genetic diversity is still lacking, particularly in the Andaman Sea. The region suffered a massive heat-induced bleaching event in 2010 with high coral cover loss of branching coral species such as P. acuta. A subsequent bleaching in 2016, however, revealed a mild bleaching response in pocilloporids compared to other coral taxa in the region, suggesting that rare, heat tolerant genotypes had been selected by the 2010 bleaching event. In order to test whether this potential ‘evolutionary rescue’ event has led to a low genetic diversity, we conducted a population genetic survey covering a total of nine different P. acuta populations (336 individuals) along a 50 km coastal stretch around Phuket Island, Thailand. We used six microsatellite markers to assess genotypic diversity and to determine the prevalent mode of reproduction (i.e. sexual or asexual recruitment).ResultsIn contrast to other Indian Ocean P. acuta populations, the majority of corals in this study adopted a sexual reproduction mode (75% across all populations). At the same time, substantial regional gene flow was observed around Phuket Island with strong genetic differentiation as indicated by three genetic clusters that were separated by only a few kilometers. Patterns of isolation by distance over 0.7 – 40 km suggest small-scale genetic barriers, such as changing currents throughout each monsoonal season, potentially contributing to locally restricted dispersal of P. acuta larvae.ConclusionsThe occurrence of distinct genetic clusters within short coastal stretches suggests that the 2010 bleaching event has not led to extreme genetic impoverishment. While more in-depth genomic analyses are necessary to investigate changes in genetic diversity following extreme bleaching events, our results will help guide conservation efforts to maintain genetic diversity of a coral species that likely will be dominant in future, warmer Andaman Sea reefs.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

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