Sinularia australiensis, Ofwegen, Leen P. van, Benayahu, Yehuda & McFadden, Catherine S., 2013

Ofwegen, Leen P. van, Benayahu, Yehuda & McFadden, Catherine S., 2013, Sinularia leptoclados (Ehrenberg, 1834) (Cnidaria, Octocorallia) re-examined, ZooKeys 272, pp. 29-59 : 32-34

Sinularia australiensis sp. n. Figs 1-4

? Sinularia leptoclados ; Lüttschwager, 1915: 3 (West Australia); Macfadyen: 37 (Great Barrier Reef Australia).

Sinularia leptoclados ; Ofwegen, 2008a: 131; McFadden et al.: 320 (Gulf of Carpentaria, West Australia).

Material examined.

Holotype: NTM C14519, Australia, Northern Territory, Gulf of Carpentaria, West of Bremer island, 12°05.660'S, 136°47.754'E, depth 1-3 m, coll. P. Alderslade & party, 17 December 2003. Paratypes: NTM C14492,C14520, C14521, same data as holotype.

Description.

The holotype is 6 cm high and 9.5 cm wide, attached to a piece of rock (Fig. 1A). The middle part of the colony is devoid of lobes, possibly a colony in the process of colony fission. The primary lobes branch off once or twice, lobules knob- to finger-shaped, up to 4 mm wide and 1 cm long.

The polyps have a collaret and eight points. Points with poorly developed clubs, up to 0.15 mm long (Fig. 2A). Collaret has bent spindles, up to 0.20 mm long (Fig. 2B). Tentacle sclerites were not present.

The surface layer of the lobules has leptoclados-type clubs, the smallest are 0.07 mm long, most are around 0.10 mm, but some even reach a length of 0.15 mm (Fig. 2C); in addition, longer wart clubs are present, up to 0.25 mm long (Fig. 2D). Furthermore, the surface layer of the lobules has spindles, up to 0.40 mm long, with simple tubercles (Fig. 2E).

The sclerites of the surface layer of the base of the colony resemble those of the surface layer of the lobules but the clubs have wider handles and the spindles are wider (Fig. 3).

The interior of the colony has mostly unbranched spindles; a few have one or two side branches. In the lobules the spindles are up to 2.5 mm long (Fig. 4A), almost all having simple tubercles (Fig. 4B). In the base of the colony they are up to 3 mm long (Fig. 4C), with more complex tubercles (Fig. 4D).

Colour.

The preserved specimen is brown.

Etymology.

Named after Australia, where the type was collected.

Intraspecific variation.

NTM C14492 (Fig. 1B) and NTM C14521 (Fig. 1D) have stouter lobules, up to 1 cm wide.

Remarks.

The species resembles Sinularia leptoclados regarding clubs and colony shape. It differs in having small surface lobule spindles with uniformly placed tubercles and many internal lobule spindles with simple tubercles. Other species resembling Sinularia australiensis are Sinularia acuta Manuputty & Ofwegen, 2007, S. corpulentissima Manuputty & Ofwegen, 2007 and Sinularia longula Manuputty & Ofwegen, 2007, all three described from Ambon. Sinularia acuta and Sinularia longula have more slender spindles and wart clubs in the surface layer of the lobules ( Manuputty and Ofwegen 2007: Figs 3, 19). Sinularia corpulentissima , like Sinularia leptoclados , differs in having many internal spindles with complex tubercles (Manuputty and Ofwegen: Fig. 7c). Moreover, in the current molecular study Sinularia corpulentissima is assigned to a distinct subclade together with Sinularia maxima , while Sinularia acuta and Sinularia longula fall into a separate well-supported subclade (Figs 16, 17). Sinularia australiensis sp. n. does not belong to either of those subclades, but is close genetically to Sinularia leptoclados and Sinularia abrupta . The latter species has clubs resembling those of Sinularia leptoclados and Sinularia australiensis , but a totally different colony shape, with ridges instead of lobes with lobules.

Lüttschwager (1915) and Macfadyen (1936) had Sinularia material from Australia that could belong to Sinularia australiensis , but re-examination of sclerites of these specimens is necessary to confirm this possibility