MEPS 295:113-121 (2005)  -  doi:10.3354/meps295113

Fluctuating algal symbiont communities in Acropora palifera (Scleractinia: Acroporidae) from Taiwan

Chaolun Allen Chen1,2,*, Jih-Terng Wang3, Lee-Shing Fang4, Ya-Wen Yang1

1Research Center for Biodiversity, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
2Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan, ROC
3Department of Food Science and Technology, Tajen Institute of Technology, Yanpu, Pingtung 907, Taiwan, ROC
4National Museum of Marine Biology and Aquarium, Hengchun, Pingtung 946, Taiwan, ROC

ABSTRACT: Seasonal dynamics of algal symbiont communities from the reef flat-dwelling coral Acropora palifera was monitored from January 2000 to July 2001 at Tantzei Bay, Kenting National Park, southern Taiwan. Zooxanthellae density and pigment contents monitored throughout the 18 mo sampling period indicated that no significant bleaching occurred in A. palifera. Molecular phylotyping showed that 2 distinct symbionts, Phylotypes C and D, were associated with A. palifera, either individually or simultaneously. Population surveys throughout the bimonthly sampling period demonstrated that the symbiont community within A. palifera was highly dynamic with significant fluctuations; a drop in the Phylotype D percentage occurred in May, which was correlated with a rise in seawater temperature in the late spring/early summer at the sampled reef. Direct tracking of tagged corals provided evidence that seasonal fluctuations in the algal symbiont communities not only involve changes in zooxanthellae densities and pigment contents, but also a reshuffling of different Symbiodinium phylotypes. Our study highlights that stress tolerance among phylotypes urgently needs to be re-evaluated through a better understanding of the physiological traits of symbionts.

KEY WORDS: Symbiont community · Phylotype · Stress tolerance · nlsrDNA RFLPs · Symbiont reshuffling

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