Ovabunda crenata (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 : 17-19

Ovabunda crenata (Reinicke, 1997) comb. n. Fig. 10

Xenia crenata Reinicke, 1997: 41-42, figs 3c, 15; plates 5, 25.

Material.

Holotype: RMNH Coel. 23538, Sudanese Red Sea, Sanganeb Atoll, 20 km off Port Sudan, S-slope near jetty (19°21'33.81"N, 37°19'37.66"E), 10 m, April 1991, coll. G.B. Reinicke; additional material: RMNH Coel. 23517, Sudanese Red Sea, Sanganeb Atoll, lagoon slope, TQ II station, 8 m, March 1991, coll. G.B. Reinicke; type of Xenia viridis SMF 42, Indonesia, Ternate island, 1894, coll. Kükenthal; type of Xenia blumi SMF 44, Indonesia, Ternate island, 1894, coll. Kükenthal.

Description.

The holotype is 30 mm high and 10 mm wide at its base. The stalk splits into two branches. The first is 15 mm long, 6 mm wide at its base and 10 mm wide at its uppermost part; the second splits further into two branches, 15 and 7 mm long, each 5 mm wide at the base, and 10 and 7 mm wide at the upper part, respectively. Polyp’s body is up to 5 mm long and the tentacles up to 5 mm long. The pinnules are mostly arranged in two rows, with an occasional third row. There are 12-16 pinnules in the outermost row, 1 mm long and 0.14 mm wide, with a 0.2 mm space between adjacent pinnules. Sclerites are very scarce in all parts of the holotype; they are Ovabunda -type spheroids, measuring 0.012-0.028 × 0.018-0.036 mm in diameter (n = 35 sclerites). Occasionally, two sclerites are fused, reaching 0.050 mm in maximal diameter. SEM micrographs of sclerites were obtained only from the additional material due to low density of sclerites in the holotype. Reinicke (1997) recorded non-pulsating polyps for the species. The ethanol preserved holotype is light beige.

Remarks.

RMNH Coel. 23517 is similar in size to the holotype. Polyp’s body is up to 2 mm long, with 2 mm long tentacles, mostly bearing two rows of 1 mm long and 0.1 mm wide slender pinnules on each of the tentacle sides, and, rarely, a third row. The outermost row features 12-15 pinnules, up to one pinnule-width apart. Sclerites are of the Ovabunda -type, varying in shape from regular ( Fig. 10a ), egg-shaped ( Fig. 10c ) and more rectangular ( Fig. 10d ), ranging 0.016-0.026 × 0.028-0.040 mm (n = 25 sclerites) in diameter. Occasionally, two sclerites are fused, reaching 0.047 mm in maximal diameter ( Fig. 10b ).

Reinicke (1997) noted under the description of Xenia crenata sp. n. (p. 41): "? Xenia blumi Schenk 1896; Gohar 1940: 98, Plate 5 " and " Xenia blumi Schenk 1896 sensu Gohar - Reinicke 1995: 42, Fig. 31". Reinicke (1997) also noted: "? Xenia viridis Schenk 1896; Benayahu 1990: 115 (listed)". The description of Xenia blumi according to Gohar (1940) does not match Ovabunda crenata features. Examination of the types of Xenia blumi and Xenia viridis during the current study (see Table 1 ) revealed them to have platelet-shaped sclerites composed of dendritic rods, and to differ from Ovabunda crenata .

Conclusions.

The original description of the holotype indicated three rows of pinnules, whereas the present examination revealed mostly two rows, with an indication of a third one. There is agreement between our findings and the original description regarding the number of pinnules in the outermost row of the tentacles (12-16 vs. 12-15, respectively). Sclerites correspond to the original description in size but are Ovabunda -type spheroids; therefore, it is concluded that the species should be assigned to Ovabunda .

Similar species.

Ovabunda crenata is most similar to Ovabunda biseriata . Although they both have overlapping number of pinnules in the outermost row, 12-16 and 13-16, respectively, Ovabunda biseriata has two rows of pinnules and Ovabunda crenata occasionally presents a third row. They both have non-pulsating polyps in live colonies.

Distribution.

Red Sea: Gulf of Aqaba, Sudan.

Figures

Figure 5. Scanning electron micrographs of polyp sclerites of Xenia crista Reinicke, 1997 holotype (RMNH 18677). a Regular sclerites b-c Fused sclerites d White rectangle in c indicates magnified area. Scale bar 10 µm.

Figure 10. Scanning electron micrographs of polyp sclerites of Ovabunda crenata (Reinicke, 1997) (RMNH Coel. 23517). a Regular sclerites b Fused sclerites c Egg-shaped sclerites d Rectangular sclerite. Arrows indicate surface dents. Scale bar 10 µm.