Ovabunda ainex (Reinicke, 1997) Halász & McFadden & Aharonovich & Toonen & Benayahu, 2014

Halasz, Anna, McFadden, Catherine S., Aharonovich, Dafna, Toonen, Robert & Benayahu, Yehuda, 2014, A revision of the octocoral genus Ovabunda Alderslade, 2001 (Anthozoa, Octocorallia, Xeniidae), ZooKeys 373, pp. 1-41 : 7-8

Ovabunda ainex (Reinicke, 1997) comb. n. Fig. 3

Xenia ainex Reinicke, 1997: 45-48, figs 19a-b, plates 6, 26.

Material.

Holotype: RMNH Coel. 23539, Sudanese Red Sea, Sanganeb Atoll, 20 km off Port Sudan, southern-slope near jetty (19°21'33.81"N, 37°19'37.66"E), 6 m, April 1991, coll. G. B. Reinicke; paratype: RMNH Coel. 23540, same location, 5 m S- jetty, October 1992, coll. G. B. Reinicke; additional material: RMNH Coel. 23535, Red Sea, Gulf of Aqaba, Aqaba, Saudi Arabian border Bay (29°21'37.31"N, 34°57'39.48"E), October 1989, coll. G. B. Reinicke; NHMW 2250, Saudi Arabia; holotype of Xenia crassa SMF 39, Indonesia, Ternate island, 1894, coll. Kükenthal; holotype of Xenia ternatana SMF 43, Indonesia, Ternate island, 1894, coll. Kükenthal.

Description.

The holotype is 45 mm high; its stalk is 15 mm long and splits at the base into three branches, two of which split again into two, 22 and 18 mm above the colony base; the latter branches are 35 and 30 mm long, 8 and 10 mm wide at their base, 4 and 6 mm wide at their uppermost part, respectively. The third branch splits 20 mm above the base into three branches, and is 40 mm long and 7 mm wide at its base and 5-7 mm wide at the uppermost part. The polyp’s body is up to 10 mm long, and the tentacles are up to 5 mm long, featuring three rows of pinnules on each side. The pinnules are relatively slender, up to 1 mm long and 0.08 mm wide, 17-20 in the outermost row with a space of one to two pinnule widths between adjacent pinnules. The spheroidal sclerites, typical regular Ovabunda sclerites, are scarce in all parts of the colony, measuring 0.011-0.030 × 0.018-0.042 mm in diameter (n = 25), composed of a mass of corpuscle-shaped microscleres. The original description indicated non-pulsating polyps for the live colonies. The ethanol-preserved holotype is light yellowish-beige, almost transparent.

The paratype is 20 mm long; its stalk is 15 mm wide at its base, splitting into two branches, each 5 mm long and 10 and 8 mm wide at the base. The polyp’s body is up to 5 mm long, and the tentacles up to 5 mm long, bearing three rows of pinnules and 15-17 pinnules in the outermost row. The pinnules are 1.6 mm long and 0.16 mm wide, with a gap between adjacent pinnules ranging from one to three pinnule widths. The sclerites are Ovabunda vabunda -type, regular or irregular in shape ( Fig. 3a, c ), 0.012-0.026 × 0.02-0.04 mm in diameter (n = 21 sclerites). When two sclerites fuse they reach 0.039 mm in maximum diameter ( Fig. 3b ). The original description indicated non-pulsating polyps for live colonies. The ethanol-preserved colony is light beige.

Remarks.

RMNH Coel. 23535 features polyps with three rows of pinnules on each side of the tentacles and 16-19 pinnules in the outermost row. The sclerites are Ovabunda -type, measuring 0.016-0.026 × 0.022-0.030 mm in diameter (n =13).

Reinicke (1997) noted under the species Xenia ainex n.sp. (p. 44): "nec Xenia ternatana ; Kükenthal 1913: 8 (partim. NHMW 2250)" and " Xenia crassa ; Reinicke 1995: 43, Fig. 32". The description of Xenia ternatana given by Kükenthal (1913) indicated two rows of pinnules, with 18 pinnules on average, and sclerites measuring 0.017 mm in diameter, thus differing from the features of Ovabunda ainex (see above). The NHMW 2250 specimen of Xenia ternatana was examined and found to match Ovabunda ainex , as stated by Reinicke (1997). Xenia crassa was suggested to be a synonym of Ovabunda ainex ( Reinicke 1997). The current examination of the types of Xenia crassa and Xenia ternatana indicates that their sclerites distinctly differ from those of Ovabunda ainex , and thus those species’ original generic assignment should be retained.

Conclusions.

Our findings confirm the original description of Reinicke (1997) of Ovabunda ainex , but the structure of its sclerites justifies the generic re-assignment of the species to Ovabunda .

Similar species.

Ovabunda ainex is most similar to Ovabunda macrospiculata . Although they both have three rows of pinnules, the number of pinnules in the outermost row ranges from 15-20 in Ovabunda ainex compared to 14-18 in Ovabunda macrospiculata . The major difference between them, however, is that Ovabunda macrospiculata has pulsating polyps in live colonies and Ovabunda ainex does not.

Distribution.

Red Sea: Gulf of Aqaba, Sudan.

Figures

Figure 3. Scanning electron micrographs of polyp sclerites of Ovabunda ainex (Reinicke, 1997) paratype (RMNH Coel. 23540). a Regular sclerites b Fused sclerites c Irregular sclerite. Arrows indicate surface dents. Scale bar: 10 µm.