Ovabunda biseriata (Verseveldt & Cohen, 1971)

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 : 14-17

Ovabunda biseriata (Verseveldt & Cohen, 1971) Figs 8 ,9

Xenia biseriata Verseveldt & Cohen, 1971: 60, table 1; Benayahu 1990 table 1 listed only; Reinicke 1997: 33, plate 20.

Xenia obscuronata Verseveldt & Cohen, 1971: 60, table 1, fig 10; Benayahu 1990 table 1 listed only; Reinicke 1997: 33, 35, plates 2, 4, 7, 21.

Ovabunda biseriata ; Alderslade 2001: 51; Aharonovich and Benayahu 2011.

Ovabunda obscuronata ; Alderslade 2001: 5, syn. n.

Material.

Holotype and five paratypes: HUJ I Co. 72, northern Red Sea, Gulf of Aqaba, Marsa Murach (29°25'34.44"N, 34°50'10.46"E), 1-4 m, 15 September 1969, coll. Y. Cohen; holotype of Ovabunda obscuronata HUJ I Co. 120, northern Red Sea, Gulf of Aqaba, Ras el Muqebla (29°24'1.20"N, 34°48'41.99"E), 12 m, 16 August 1971, coll. Y. Cohen; holotype of Xenia ternatana SMF 43, Indonesia, Ternate island, 1894, coll. Kükenthal.

Description.

The holotype is 28 mm high, stalk is 15 mm long, 11 mm wide at its base and 10 mm wide at the uppermost part; it is attached to the skeleton of a stony coral. Polyp’s body reaches up to 8-10 mm, and the tentacles 6-7 mm, bearing pinnules up to 1 mm long and 0.24 mm wide, separated by less than a pinnule-width. Two rows of pinnules are aligned along each of the tentacles margins, with 13-15 pinnules in the outermost row. There are numerous sclerites, abundant in all parts of the colony except for the mid-line of the oral side of the tentacles, where they are scarce. The sclerites are Ovabunda -type ( Fig. 8 ), measuring 0.013-0.029 × 0.018-0.039 mm in diameter (n = 100 sclerites). Rarely, two sclerites are fused, reaching a maximum diameter of 0.048 mm and occasionally 0.060 mm. The paratypes are of similar size to the holotype, featuring tentacles with two rows of pinnules and 13-16 pinnules in the outermost row. The stalk of the smallest paratype is divided into two branches; the paratype tentacles bear two rows of pinnules with 10-12 pinnules in the outermost row. The sclerites of all paratype colonies are Ovabunda -type, ranging 0.018-0.025 × 0.023-0.039 mm in diameter. The original description of the species indicated non-pulsating polyps in live colonies. The preserved colonies are yellowish-light beige in colour.

Remarks.

In general the original description of the species corresponds to the current findings. SEM micrographs of the holotype sclerites ( Fig. 8 ) indicate that they are indeed Ovabunda -type, and therefore further confirm the previous assignment to that genus ( Alderslade 2001; Aharonovich and Benayahu 2011). The number of rows of pinnules, the number of pinnules in the outermost row, and the dimensions of the holotype colony of Ovabunda obscuronata (HUJ I Co. 120) correspond to the original description by Verseveldt and Cohen (1971). The sclerites are oval spheroids, Ovabunda -type, ranging 0.012-0.026 × 0.018-0.041 mm in diameter ( Fig. 9 , n = 61 sclerites). Rarely, two sclerites are fused, reaching a maximal diameter of 0.060 mm. The original description indicated a maximum diameter of 0.045 mm for the stalk sclerites, 0.060 mm for those of the anthocodiae and "irregular spicules" in the tentacles ( Verseveldt and Cohen 1971: 60). The latter probably referred to fused sclerites, which were not identifiable under light microscopy. The original description of Ovabunda obscuronata indicated non-pulsating polyps in live colonies, similar to Ovabunda biseriata . The ethanol-preserved holotype is light brown in colour.

Reinicke (1997) noted under the description of Xenia obscuronata (p. 33): "nec Xenia ternatana ; Kükenthal 1913: 8 (in part)". The type of Xenia ternatana was examined during the present study and its features do not agree with those of Ovabunda obscuronata . Xenia ternatana features platelets composed of dendritic rods, measuring up to 0.022 mm in maximal diameter. It should be noted that the description of Xenia ternatana by Kükenthal also does not correspond to the features of Ovabunda obscuronata .

Conclusions.

Examination of the holotype of Ovabunda biseriata and Ovabunda obscuronata revealed certain similarities, as already noted in the original description ( Verseveldt and Cohen 1971): two rows of pinnules, with 12-15 vs. 14-16 pinnules, respectively, in the outermost row. The original description noted differences in the size of sclerites; 0.018-0.035 mm in Ovabunda biseriata vs. 0.045 mm in the stalk and anthocodiae and 0.060 mm in the tentacles of Ovabunda obscuronata . The current examination revealed a similar size range in the two species (0.013-0.029 × 0.018-0.039 vs. 0.012-0.026 × 0.018-0.041, respectively). Therefore, it is concluded that Ovabunda biseriata and Ovabunda obscuronata are in fact synonyms, giving alphabetical priority to the former.

Similar species.

Ovabunda biseriata is most similar to Ovabunda impulsatilla and Ovabunda faraunensis . Although they all have two rows of pinnules and non-pulsating polyps in living colonies, the number of pinnules in the outermost row ranges from 13-16 in Ovabunda biseriata compared to 8-11 in Ovabunda impulsatilla and 17-24 in Ovabunda faraunensis .

Distribution.

Red Sea: Gulf of Aqaba, Gulf of Suez, Sudan.

Figures

Figure 8. Scanning electron micrographs of polyp sclerites of Ovabunda biseriata (Verseveldt & Cohen, 1971) holotype (HUJ I Co. 72). Arrow indicates surface dents. Scale bar 10 µm.

Figure 9. Scanning electron micrographs of polyp sclerites of Ovabunda obscuronata (Verseveldt & Cohen, 1971) holotype (HUJ I Co. 120). Scale bar 10 µm.