Latitudinal variation in algal symbionts within the scleractinian coral Galaxea fascicularis in the South China Sea

Abstract

The diversity of symbiotic algae of the genus Symbiodinium (Symbiodinium sp.) within a widespread ranging scleractinian coral Galaxea fascicularis along latitudinal gradients in the South China Sea was examined using restriction fragment length polymorphism (RFLP) of the large subunit rDNA and sequencing. It revealed that G. fascicularis was associated with two distinct zooxanthellae clades. Galaxea fascicularis sampled in Daya bay in Guangdong province harboured Symbiodinium Clade C, while G. fascicularis sampled in Sanya Bay of Hainan Island, Yongxing Island of Xisha Islands, and Zhubi Reef of Nansha Islans harboured Symbiodinium Clade C and D either simultaneously or sequentially, indicating symbiosis flexibility. A distinct latitudinal distribution of Symbiodinium sp. in G. fascicularis was also revealed. Galaxea fascicularis hosting two clades of Symbiodinium sp., especially Symbiodinium clade D, may provide hosts with a flexible mechanism for adaptation to environmental change and can more easily survive mass coral bleaching events.

Keywords:

• Galaxea fascicularis
• restriction fragment length polymorphism
• Symbiodinium
• symbiotic algae

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,University of Copenhagen, Denmark

Acknowledgements

The authors express their thanks to anonymous reviewers whose comments helped improve the final version of the manuscript. This work was supported by grants from the National Natural Science Foundation of China (Nos. 40776085 and 40576052), State Oceanic Administration of China (908-ST-01-08-Coral Reefs Survey) and Bureau of Science and Technology for Resources and Environment (YTZJJ0502).

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,University of Copenhagen, Denmark