Sinularia choui, Benayahu & van Ofwegen, 2011

Benayahu, Y. & van Ofwegen, L. P., 2011, New Species Of The Genus Sinularia (Octocorallia: Alcyonacea) From Singapore, With Notes On The Occurrence Of Other Species Of The Genus, Raffles Bulletin of Zoology 59 (2), pp. 117-125 : 118-122

publication ID	https://doi.org/ 10.5281/zenodo.4508418
DOI	https://doi.org/10.5281/zenodo.4508943
persistent identifier	https://treatment.plazi.org/id/820C87A0-FFA9-255E-FEAA-4EEDFDB1D810
treatment provided by	Carolina
scientific name	Sinularia choui
status	sp. nov.

Treatment

Sinularia choui View in CoL , new species

( Figs. 1 View Fig a–4)

Material examined. – Holotype ( ZRC 1999.2249 View Materials ) and four microscope slides deposited at TAU ( ZMTAU Co 35103), Terumbu Penpang Tengah, 2–4 m, coll. Y. Benayahu, 14 Jul. 1999.

Diagnosis. – The holotype is a stalked colony, with a maximum cross-section of 2 × 4 cm and 5 cm high ( Fig. 1a View Fig ). The polypary consists in densely placed lobes that bear lobules with a rounded tip. Some of the polyps are partially retracted and visible on the surface of the lobules.

The polyps have a collaret and eight points. The point sclerites have poorly developed heads, up to 0.19 mm long ( Fig. 2a View Fig ). The collaret spindles are slightly bent, 0.13–0.24 mm long, featuring sparse tubercles on their surface ( Fig. 2b View Fig ).

The surface layer of the lobules has leptoclados - type clubs, 0.10–0.26 mm long, whose heads mostly feature pointed leaf-like processes ( Fig. 2c View Fig ). In addition, there are clubs, up to 0.24 mm long, with heads featuring a prominent warty ornamentation ( Fig. 3a View Fig ), and others that are even longer, up to 0.38 mm ( Fig. 3b View Fig ). The surface of the lobes has spindles, up to 0.51 mm long, with warty tubercles that are occasionally more common at one end of the spindle than the other ( Fig. 3c View Fig ).

The clubs with leaf-like processes on the surface layer of the colony base are 0.10–0.17 mm long ( Fig. 4a View Fig ). They have wider handles and are shorter compared to those of the lobules’ surface. Some of these clubs, up to 0.30 mm long, feature heads with a warty ornamentation ( Fig.4b, c View Fig ). In addition, there are capstan-like sclerites, 0.10–0.16 mm long ( Fig. 4d View Fig ). The spindles of the surface of the base are shorter than those of the surface of the lobes, up to 0.37 mm long ( Fig. 4e View Fig ).

The interior of the lobules has spindles, up to 1.95 mm long, some bent and with a side branch ( Fig. 3d View Fig ). Most of the spindles have sparsely dispersed small tubercles ( Fig. 3e View Fig ), but a few have more densely located and larger ones ( Fig. 3f View Fig ). The spindles in the interior of the base are up 1.90 mm long ( Fig. 4f View Fig ) with a dense tubercular sculpture ( Fig. 4g View Fig ).

Colour. – The preserved holotype is light cream.

Etymology. – The species name honours Prof. L. M. Chou, National University of Singapore, a prominent coral reef scientist, in appreciation of his initiative to conduct a soft coral survey in Singapore and in recognition of his immense contribution to the study of the Singapore reefs.

Remarks. – Based on the presence of leptoclados - type clubs, collaret and point sclerites we assigned S. choui to clade 5C of McFadden et al. (2009). Within this clade, S. pumila Dautova et al., 2010 reveals two types of clubs in the surface layer of the lobes, with head either featuring pointed leaf-like processes or a warty ornamentation. In S. choui the clubs are larger than in S. pumila : the leafy ones reach up to 0.26 mm compared to 0.15 mm; the warty ones, 0.38 mm compared to 0.26 mm, respectively. Similarly, in S. choui most of the clubs of the surface layer of the base are longer than 0.10 mm ( Fig. 4a View Fig ), whereas in S. pumila they are 0.10 mm long or less ( Dautova et al. 2010: Fig. 18). Hence, we conclude that S. choui has unique sclerite features, and does not resemble any congeneric species already described.