Paragorgia regalis Nutting, 1912

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 : 25-29

Paragorgia regalis Nutting, 1912

( Figs. 13–15 )

Paragorgia regalis Nutting 1912: 100 .

Paragorgia dendroides Bayer 1956: 69 (sensu Bayer 1964: 526) ; Grasshoff 1979: 120.

Material examined. Holotype: USNM 30018, 34°15’N –138°E, 869–924 m, Honshu island, Omae Zaki, 19 October 1906 (col. Albatross R/V), Saizuoka, Japan.

Other material: USNM 98789 (previously identified as P. dendroides by. F.M. Bayer), 20° 46’ 57”N – 157° 08’ 56”W, 1018 m, 20 September 1996 ( Pisces DSR/ V 5­301, LAD 115), col. S. France & E. Bertson, Hawaii, USA; USNM 1014743 (previously identified as P. dendroides by. F.M. Bayer), 19 44 12 N­ 158 17 43W, 452 m, Cross Seamount (River Basin), 5 February 2003 (col. R.B. Moffitt­OES 03­01 & E.H. Cave), USA.

Diagnostic characters. Autozooid polyps clustered in distinct and smooth globular nodules up to 2–3 mm high ( Fig. 13 ). Surface cortex sclerites are small 7­ and 8­radiates, up to 0.08 mm including rays, with smooth surfaces. The small ones are greatly asymmetrical and integrating rays with distinctive small lumps (e.g., Figs. 14 B–D, 15C–E).

Description. Profusely branching colonies up to 300 mm in length with slender terminal branches down to 2–4 mm in diameter (Grasshoff 1979: Figs. 2–3 ). A few long, lateral branches arise from the main branches and have a clavate appearance. Medulla perforated by 3–4 large canals ( Bayer 1956b: 69). Autozooid polyps on all sides of branches ( Bayer 1956b: 69) but with tendency towards one side ( Fig. 13 ). Autozooids clustered in distinct globular nodes up to 2–3 mm in height; siphonozooids much smaller (0.5 mm in height) but distributed throughout the surface ( Bayer 1956b: 69). Salmon pink color. Autozooid polyp tentacles contain ovals up to 0.1 mm in length, irregularly ornate with small conical tubercles ( Figs. 14 A: 15A–B). Surface of the cortex, including autozooid apertures, with small 7­ and 8­radiate sclerites up to 0.08 mm long but averaging 0.06–0.07 mm (0.003 SD, n=10, Holotype; 0.005 SD, n=10, USNM 98789). Rays with smooth surfaces but greatly asymmetrical in the smaller 7­radiate forms ( Figs. 14 B–D: 15C–E). Surface radiates about 1.6–1.7 times longer than wider, averaging 0.035–0.043 mm in width (0.002– 0.003 SD). The subsurface/outer medulla with larger, chiefly 8­radiates, up to 0.1 mm in length ( Bayer 1956b: 69). Medulla with ornate, coarsely warted spindles, oftentimes forked and ramified, up to 0.5 mm in length but frequently smaller ( Figs. 14 E; 15F).

Morphological variation. Surface sclerites, which include the diagnostic forms for most Paragorgia species, are quite variable in P. regalis . The sclerite drawings by Bayer (1956b: Fig. 1 ) are clearly the forms from the subsurface, which are usually large 8­radiates, and were also observed in the studied material (e.g., Fig. 14 B–D). Since only two specimens were examined, a larger survey is needed to determine if Japanese specimens (type locality) differ from Hawaiian populations (e.g., P. dendroides, Bayer 1993 ).

Distribution. Pacific Ocean, Hawaii and Japan, 452–1018 m.

Species comparisons. Bayer (1964: 526) was the first who suggested that P. dendroides (Bayer 1956) should be a junior synonymy of P. regalis based on sclerite morphology. It is clear that sclerites from the type material of P. regalis ( Japan) resemble those of the Hawaiian specimens identified by F.M. Bayer as P. dendroides . Nonetheless, a detailed revision of specimens throughout the Pacific is needed to clarify the synonymy of P. d e n ­ droides and/or the presence of a morphological cline across the Pacific. In comparison with other Paragorgia species, the 8­radiates from the subsurface/outer medulla of P. regalis resemble those from P. johnsoni and P. splendens , but the smaller forms in P. johnsoni are smoother without the irregular ornamentation observed in P. regalis and the colonial features from P. splendens are quite different to those of P. regalis .

Figures

FIGURE 1. Geographical locations of the known Paragorgiidae species (see Fig. 2 for New Zealand detail).

FIGURE 2. Map of New Zealand and overall underwater landscape showing the locations and distribution of Paragorgiidae species.

FIGURE 3. Major types of surface cortex radiate sclerites: A – B, 6 ­ radiates; C, 7 ­ radiate; D, 8 ­ radiate.

FIGURE 13. Photograph of Paragorgia regalis Nutting (USNM 98789).

FIGURE 14. Paragorgia regalis Nutting, holotype (USNM 30018): A, sclerites from the polyps (scales 10 m); B – D, radiate sclerites from the colony surface (scales 10 m) (B – C are stereo pairs); E, sclerites from the colony medulla (scales 100 m and 20 m).

FIGURE 15. Paragorgia regalis Nutting (USNM 98789): A – B, sclerites from the polyps (A is a stereo pair) (scale 20 m); C – E, radiate sclerites from the colony surface (scales 10 m) (C – D are stereo pairs); F, sclerites from the colony medulla (scales 100 m).