Zoological Studies

Vol. 57, 2018

(update: 2018.11.01; 11.20) 

Repeated and Prolonged Temperature Anomalies Negate Symbiodiniaceae Genera Shuffling in the Coral Platygyra verweyi (Scleractinia; Merulinidae)

Kuo-Wei Kao1,2, Shashank Keshavmurthy1,*, Cing-Hsin Tsao1,2, Jih-Terng Wang3, and Chaolun Allen Chen1,2,4,*

1Academia Sinica, Biodiversity Research Center, Taipei, Taiwan. E-mail: weberkao@gmail.com (Kao); coralresearchtaiwan@gmail.com (Keshavmurthy); stevetaso123@gmail.com (Tsao); jtwtaiwan@gmail.com (Wang)
2National Taiwan University, Institute of Oceanography, Taipei, Taiwan
3Tajen University of Science and Technology, Institute of Biotechnology, Pingtung, Taiwan
4Academia Sinica, Taiwan International Graduate Program (TIGP) - Biodiversity, Taipei, Taiwan

(Received 16 May 2018; Accepted 15 October 2018; Communicated by Benny K.K. Chan)

Kuo-Wei Kao, Shashank Keshavmurthy, Cing-Hsin Tsao, Jih-Terng Wang, and Chaolun Allen Chen (2018) With climate change, global average sea surface temperatures are expected to increase by 1.0-3.7C by the end of this century. Even a 1.0C increase in seawater temperature from local long-term summer maxima lasting for weeks to months results in bleaching and/or mortality in reef-building corals. Studies on coral resistance mechanisms have proposed a correlation between shuffling of different Symbiodiniaceae genera (changing the dominant Symbiodiniaceae genera) and putative thermal tolerance in corals. Although it was suggested that some corals can increase their tolerance by 1.0-1.5C through shuffling to thermally tolerant Durusdinium trenchii (formerly D1a), the effects of accumulated thermal stress due to prolonged high temperatures on the survival of corals that have shuffled have not been investigated. We show herein that prolonged exposure to high temperature (> 10.43 degree heating weeks) can drastically reduce coral survival rate even after it has shuffled to stress-tolerant Symbiodiniaceae genera. Our study suggests that there is a limit to the capacity of for shuffling, and hence is likely to lose its efficacy in the future as repeated and prolonged thermal stress events become more frequent and pronounced.

Key words: Climate change, Seawater temperature fluctuations, Degree of heating weeks, Reciprocal transplantation, Kenting-Taiwan.

*Correspondence: E-mail: cac@gate.sinica.edu.tw; coralresearchtaiwan@gmail.com

Supplementary Materials: Fig. S1 | Table S1 | Table S2 | Table S3 | Table S4 | Table S5 | Table S6 | Table S7 | Table S8