Characterization of fungal biodiversity and communities associated with the reef macroalga Sargassum ilicifolium reveals fungal community differentiation according to geographic locality and algal structure
Marine environments abound with opportunities to discover new species of fungi even in relatively well-studied ecosystems such as coral reefs. Here, we investigated the fungal communities associated with the canopy forming macroalga Sargassum ilicifolium(Turner) C. Argardh (1820) in Singapore. We collected eight S. ilicifolium thalli from each of eight island locations and separated them into three structures—leaves, holdfast and vesicles. Amplicon sequencing of the fungal internal transcribed spacer 1 (ITS1) and subsequent analyses revealed weak but significant differences in fungal community composition from different structures. Fungal communities were also significantly different among sampling localities, even over relatively small spatial scales (≤ 12 km). Unsurprisingly, all structures from all localities were dominated by unclassified fungi. Our findings demonstrate the potential of marine environments to act as reservoirs of undocumented biodiversity that harbour many novel fungal taxa. These unclassified fungi highlight the need to look beyond terrestrial ecosystems in well-studied regions of the world, and to fully characterize fungal biodiversity in hotspots such as Southeast Asia for better understanding the roles they play in promoting and maintaining life on our planet.
KeywordsCoral reefs Fungal ITS Marine fungi Microbiome Singapore Southeast Asia
We thank Jack Darcy for the R script that allows sequence quality information to be ‘reattached’ to the processed ITSx data. Full script can be found at https://github.com/gzahn/Sargassum_Fungi/blob/master/R/itsx_fastq_extractor.r
This study was funded by the National Research Foundation, Prime Minister’s Office, Singapore, under its Marine Science R&D Programme (MSRDP-P03) and The Wildlife Reserves Singapore Conservation Fund (WRSCF). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable permits, international, national and/or institutional guidelines required to perform the work were followed. All samples were collected under permit NP/RP15-009-2a.
Sampling and field studies
All necessary permits for sampling and observational field studies have been obtained by the authors from the competent authorities. The study is compliant with CBD and Nagoya protocols. All samples were collected under permit NP/RP15-009-2a.
All sequences associated with this work have been deposited at the National Center for Biotechnology Information (https://www.ncbi.nlm.nih.gov/bioproject/) under BioProject ID: PRJNA504438.
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