Paragorgia stephencairnsi, 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 : 57-60

Paragorgia stephencairnsi sp. nov.

( Figs. 39–41 )

Material Examined. Holotype: USNM 57982, 350 m, col. N. McDaniel, exact locality unknown, off British Columbia, Canada.

Paratype: USNM 94437, 490 m, Alvin DSR/V (Dive 2296), 16 October 1990, 32 ° 26’00”N – 127 ° 47’36”W, California, USA.

Diagnostic characters. Colonies with flattened branches. Surface sclerites mostly 7­ radiates (occasionally 8­radiates) with long (> 0.01 mm) lobulated, smooth rays ( Fig. 40 D–G, 41B–D), averaging 0.065 mm in length. Medullar sclerites highly ornate, forked, irregular, spindles usually less than 0.3 mm in length (e.g., Fig. 40 H).

Description. Robust flattened branches, white cortex and pink to purple autozooid apertures. Numerous conical, semi­closed, autozooid polyp apertures uniformly/randomly distributed throughout the branches ( Fig. 39 ). Tiny siphonozooid apertures tightly closed, not observable to the naked eye. Medulla in the terminal branches with 6–7 major canals. Autozooid polyp tentacles with blunt ovals up to 0.1 mm long, regularly ornate with notable conical rays ( Fig. 40 A–B) though different overall form in the paratype ( Fig. 41 A).

Surface sclerites mostly 7­radiates, and occasionally 8­radiates, with long (> 0.01 mm) lobulated, smooth rays ( Fig. 40 D–G, 41B–D), averaging 0.065mm in length (0.005 SD, n=10). Oval surface sclerites about 1.45 times longer than wider, averaging 0.045 mm in width (0.005 SD, n=10). Medulla with highly ornate, forked, and irregular, spindles usually less than 0.3 mm in length ( Figs. 40 H).

Morphological variation. Two characters exhibited a great deal of variation between the holotype and paratype: the form of autozooid ovals and the medullar sclerites, the most variable character in Paragorgia spp. The medulla sclerites of the holotype of P. stephencairnsi sp. nov. have a great array of forked and bent forms. Since both examined specimens present the same kind of surface sclerites, which is the prevailing diagnostic character in most Paragorgia spp., they can be considered as the same species until further specimens are available.

Distribution. Pacific Ocean, off British Columbia, Canada, 350– 490 m.

Species comparisons. Externally, P. stephencairnsi sp. nov. is similar to P. yutlinux , but the two can be differentiated using sclerite form. P. yutlinux has mostly 6­radiates and P. stephencairnsi 7­radiates.

Etymology: This species is named in honour of Dr. Stephen Cairns, one of the most prolific coral taxonomists.

Figures

FIGURE 39. Paragorgia stephencairnsi sp. nov., holotype (USNM 57982) (the colony fragment is 6.5 cm in height).

FIGURE 40. Paragorgia stephencairnsi sp. nov., holotype (USNM 57982): A – B, typical polyp sclerites (scales 10 m) (A is a stereo pair); C – G, radiates from the surface (scales 10 m) (C – E – G are stereo pairs); H – I, sclerites from the medulla (scales 100 m) (H is a stereo pair) (scale 30 m).

FIGURE 41. Paragorgia stephencairnsi sp. nov., paratype (USNM 94437): A, typical polyp sclerites (scales 10 m); B – D, radiates from the surface (scales 10 m) (C – D are stereo pairs); E, sclerites from the medulla (scales 30 m).