The coastal waters of Singapore support coral reefs that are biodiverse but characterized by high turbidity and sedimentation. Here, we used internal transcribed spacer two (ITS2) amplicon sequencing to investigate the Symbiodiniaceae communities associated with this marginal reef system, as turbid reefs may serve as potential refugia from future thermal stress. Using the analytical framework SymPortal, we identified a predominance of Cladocopium among the five coral species studied across six reef sites. Durusdinium was present in comparatively lower abundances and was composed of multiple Durusdinium trenchii strains. In contrast to other marginal environments, the Cladocopium communities exhibited low diversity and lacked the host-specificity of strains reported elsewhere. Nevertheless, we identified a site-specific strain across three species, which was supported by sequencing of the non-coding region of the psbA minicircle (psbAncr). The overall low diversity of the symbiont communities suggests that, although Singapore’s reefs may provide habitat for a diverse coral assemblage, the strong selective pressure exerted by the prevalent turbidity likely limits the diversity of the associated symbiont community.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was partially carried out using the Core Technology Platforms resources at New York University Abu Dhabi, including the High Performance Computing Cluster and Sequencing Core Technology Platforms. Collection of coral samples was authorized by Singapore National Parks (NP/RP15-061). We would like to thank the Agri-Food and Veterinary Authority of Singapore for providing CITES export permit 15SG012731CE, and the UAE Ministry of Environment and Climate Change for providing the CITES import permit 15MEW4457. This study was supported by the AXA Fellowship (R-154-000-649-507) to AGB and the National Research Foundation, Prime Minister’s Office, Singapore under the Marine Science Research and Development Programme (R-154-001-A25-281 MSRDP-P03).