Sibogagorgia tautahi, JUAN ARMANDO SÁNCHEZ, 2005

JUAN ARMANDO SÁNCHEZ, 2005, Systematics of the bubblegum corals (Cnidaria: Octocorallia: Paragorgiidae) with description of new species from New Zealand and the Eastern Pacific, Zootaxa 1014, pp. 1-72 : 62

Sibogagorgia tautahi sp. nov.

( Fig. 43 )

Material examined. Holotype: NIWA 3327, H­847, J107, Z11229, 30° 1.891’S – 178° 48.061’W, “Giggenbach seamount”, 872–1086 m, 23 April 2002, (RV Tangaroa 0205/73, epibenthic sled).

Diagnostic characters. Sclerites from the medulla thick, blunt, short, mostly smooth, straight spindles that are ornate only at the tips, reaching usually less than 0.25 mm in length ( Fig. 43 F).

Description. Holotype is a small (defectively preserved) colony (<40 mm long), 5 mm diameter with 18 mm of base ( Fig. 43 G). Cortex pale brown. All sclerites colourless. Surface cortex with radiate sclerites (mostly 8­radiates) with star­like sub­radial ornamentation ( Fig. 43 A–D). Surface sclerites up to 0.09 mm long averaging 0.08 (0.007 SD, n=10). Surface radiates about 1.7 times longer than wide, averaging 0.047 mm in width (0.004 SD, n=10). Other intermediate forms in the boundary layer include irregularly enlarged radial ornamentation ( Fig. 43 E). Medulla with thick, blunt, short, mostly smooth, straight spindles, ornate only at tips, usually less than 0.25 mm in length ( Fig. 43 F).

Morphological variation. As in S. weberi , medullar spindles in S. tautahi sp. nov. are progressively less ornate towards the inner medulla, achieving higher variation at the boundary layer (e.g., Fig. 43 E). Some of the medullar sclerites are also quite robust and fatter than others ( Fig. 43 F).

Distribution. Only know from the Kermadec volcanoes seamount ridge, off the Bay of Plenty, New Zealand, 872–1086 m.

Species comparisons. S. tautahi sp. nov. has larger radiates than S. weberi , although overall they are very similar, but those of S. tautahi are more profusely ornate (sub­radial ornamentation). The diagnostic medullar spindles are shorter than those of S. weberi .

Etymology: The word tautahi means “solitary” in Maori and alludes to the sole small specimen of this species.

Figures

FIGURE 43. Sibogagorgia tautahi sp. nov., holotype (NIWA 3327): A – D, radiates from the surface (scales 10 m) (A – C are stereo pairs); E, intermediate sclerites from the subsurface / medulla (scales 10 m); F, sclerites from the medulla (scales 100 m); G. photograph of the entire colony (scale 20 mm).