A preliminary survey of zoantharian endosymbionts shows high genetic variation over small geographic scales on Okinawa-jima Island, Japan

Hatsuko Noda; John Everett Parkinson; Sung-Yin Yang; James Davis Reimer

doi:10.7717/peerj.3740

A preliminary survey of zoantharian endosymbionts shows high genetic variation over small geographic scales on Okinawa-jima Island, Japan

PeerJ. 2017 Oct 3:5:e3740. doi: 10.7717/peerj.3740. eCollection 2017.

Authors

Hatsuko Noda¹, John Everett Parkinson^{1

2}, Sung-Yin Yang^{1

3

4}, James Davis Reimer^{1

5}

Affiliations

¹ Molecular Invertebrate Systematics and Ecology Laboratory, Department of Biology, Chemistry and Marine Sciences, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
² Department of Integrative Biology, Oregon State University, Corvallis, OR, USA.
³ Microbiology and Biochemistry of Secondary Metabolites Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan.
⁴ Biodiversity Research Center, Academia Sinica, Nankang, Taipei, Taiwan.
⁵ Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa, Japan.

Abstract

Symbiotic dinoflagellates (genus Symbiodinium) shape the responses of their host reef organisms to environmental variability and climate change. To date, the biogeography of Symbiodinium has been investigated primarily through phylogenetic analyses of the ribosomal internal transcribed spacer 2 region. Although the marker can approximate species-level diversity, recent work has demonstrated that faster-evolving genes can resolve otherwise hidden species and population lineages, and that this diversity is often distributed over much finer geographical and environmental scales than previously recognized. Here, we use the noncoding region of the chloroplast psbA gene (psbA^ncr) to examine genetic diversity among clade C Symbiodinium associating with the common reef zoantharian Palythoa tuberculosa on Okinawa-jima Island, Japan. We identify four closely related Symbiodinium psbA^ncr lineages including one common generalist and two potential specialists that appear to be associated with particular microhabitats. The sea surface temperature differences that distinguish these habitats are smaller than those usually investigated, suggesting that future biogeographic surveys of Symbiodinium should incorporate fine scale environmental information as well as fine scale molecular data to accurately determine species diversity and their distributions.

Keywords: Biogeography; Diversity; Palythoa tuberculosa; Symbiodinium; Symbiosis.

Grants and funding

J.E.P was funded by the Japan Society for the Promotion of Science (JSPS). J.D.R was supported by the SATREPS P-CoRIE Project funded by the Japan Science and Technology Agency and the Japan International Cooperation Agency in cooperation with PICRIC and Palau Community College, by a JSPS ‘Zuno-Junkan’ grant entitled ‘Studies on origin and maintenance of marine biodiversity and systematic conservation planning’, as well as by a JSPS ‘Kiban-B’ grant entitled “Global evolution of Brachycnemina and their Symbiodinium”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.