Tuesday, June 7, 2016

[Cnidaria • 2014] Ovabunda andamanensis • A New Species of Ovabunda (Octocorallia, Xeniidae) from the Andaman Sea, Thailand with Notes on the Biogeography of this Genus

Ovabunda andamanensis 
 Janes, McFadden & Chanmethakul, 2014 

A survey of xeniid octocorals was carried out in the waters off Southwestern Thailand in September, 2007. Microscopic investigation of the colonies revealed that three specimens belonged to the genus Ovabunda. Gross morphological examination is presented here accompanied by scanning electron micrographs of the sclerites. Molecular phylogenetic analysis showed identical genotypes at mtMutS, COI, and 28S rDNA for all three specimens and supports their generic assignment. Colony size and shape, sclerite size, and pinnule arrangement differ from nominal species of Ovabunda and thus a new species, Ovabunda andamanensis is introduced here. This work also presents a new eastern geographical record for the genus Ovabunda.

Keywords: Cnidaria, Coelenterata, phylogeny, sclerites, SEM, soft coral, taxonomy

Systematic section
Order Alcyonacea Lamouroux, 1812
Family Xeniidae Ehrenberg, 1828

Genus Ovabunda Alderslade, 2001: 49–52
Ovabunda andamanensis sp. n.

Figure 1. In situ images of Ovabunda andamanensis sp. n.
type material Holotype (PMBC 11860):  a colony (smallest) b close up of polyps.
Paratype (PMBC 11862): 
c colony (smallest) d close up of polyps.

Etymology: The name is derived from the collection location, the Andaman Sea.

Distribution and ecology: This species was collected from Koh Doc Mai (Fig. 6) and Koh Phi Phi, Hin Bida located along the eastern coast of Phuket Island, Thailand. Colonies occur in low abundance, spaced 1-2 meters apart on small ledges of vertical walls growing among sea fans, corallimorpharians, and Dendronephthya sp. soft corals. Ovabunda andamanensis sp. n. has also been observed in situ in the Mergui Archipelago, Myanmar (T. Chanmethakul, personal observation).

Michael P. Janes, Catherine S. McFadden and Thanongsak Chanmethakul. 2014. A New Species of Ovabunda (Octocorallia, Xeniidae) from the Andaman Sea, Thailand with Notes on the Biogeography of this Genus. ZooKeys. 431: 1-17. DOI: 10.3897/zookeys.431.7751