Vol. 57, 2018

(update: 2018.10.19; 12.03) 

The Octocorals of Dongsha Atoll (South China Sea): An Iterative Approach to Species Identification Using Classical Taxonomy and Molecular Barcodes

Yehuda Benayahu^1,*, Leendert Pieter van Ofwegen², Chang-feng Dai³, Ming-Shio Jeng⁴, Keryea Soong⁵, Alex Shlagman¹, Samuel W. Du⁶, Prudence Hong⁶, Nimrah H. Imam⁶, Alice Chung⁶, Tiana Wu⁶, and Catherine S. McFadden⁶

¹School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, 69978, Israel. E-mail: shlagman@post.tau.ac.il (Shlagman)
²Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands. E-mail: ofwegen@naturalis.nl
³Institute of Oceanography, National Taiwan University, Taipei, Taiwan. E-mail: corallab@ntu.edu.tw
⁴Biodiversity Research Center, Academia Sinica, Taipei, Taiwan. E-mail: jengms@gate.sinica.edu.tw
⁵Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung, Taiwan. E-mail: keryea@gmail.com
⁶Department of Biology, Harvey Mudd College, Claremont, CA 91711-5990, USA. E-mail: samuelwdu@gmail.com (Du); phong@g.hmc.edu (Hong); nimrahimam@gmail.com (Imam), ahc2004@med.cornell.edu (Chung), 8timowu@gmail.com (Wu), mcfadden@g.hmc.edu (McFadden)

(Received 7 August 2018; Accepted 16 September 2018; Communicated by Benny K.K. Chan)

Yehuda Benayahu, Leendert Pieter van Ofwegen, Chang-feng Dai, Ming-Shio Jeng, Keryea Soong, Alex Shlagman, Samuel W. Du, Prudence Hong, Nimrah H. Imam, Alice Chung, Tiana Wu, and Catherine S. McFadden (2018) Surveys of octocorals from Dongsha Atoll, Taiwan were conducted during 2011, 2013 and 2015 by SCUBA at a depth range of 6-25 m. The collections yielded ~540 specimens, encompassing the variety of taxa occurring in the explored sites; estimates of their abundances were also recorded. Dongsha features a highly diverse octocoral fauna, and octocorals are the dominant benthic organisms in the surveyed reef sites, often covering the majority of the hard substratum. Specimens were identified to the genus and species levels based on an iterative approach that integrates classical taxonomy with character-based molecular barcodes. A total of 51 nominal species representing 20 genera belonging to seven families were recorded, plus ~30 colonies that could only be assigned to a genus. Members of the family Alcyoniidae were the most abundant and diverse taxa, with 27 nominal species plus at least one potentially new, undescribed species of Sinularia, and 5-7 species each of Cladiella, Lobophytum and Sarcophyton. Problems with the taxonomic identification and phylogenetic relationships of species in these genera are discussed. The peculiarity of the Dongsha octocoral species composition is noted, and the composition is also compared to the other Taiwanese reef systems.

Key words: Alcyonacea, Coral reefs, DNA barcoding, Pure characteristic attributes, Taiwan, Species diversity, New records.

*Correspondence: E-mail: yehudab@tauex.tau.ac.il