Plumarella alternata ( Nutting, 1912 ), 2013

TAYLOR, M. L., CAIRNS, S. D., AGNEW, D. J. & ROGERS, A. D., 2013, <strong> A revision of the genus <em> Thouarella </ em> Gray, 1870 (Octocorallia: Primnoidae), including an illustrated dichotomous key, a new species description, and comments on <em> Plumarella </ em> Gray, 1870 and <em> Dasystenella </ em>, Versluys, 1906 </ strong>, Zootaxa 3602 (1), pp. 1-105 : 97-98

Plumarella alternata ( Nutting, 1912)

Fig. 37 a,b

Thouarella alternata Nutting, 1912: 69–70 , pl. 9, figs 1, 1a, pl. 19, fig. 3; Aurivillius 1931: 255–256

Thouarella attenuata Kükenthal 1919: 438 (spelled incorrectly); 1924: 301

Thouarella (Thouarella) alternata Cairns & Bayer 2009: 27 (listed)

Plumarella alternata Cairns 2011:8

Material examined: Holotype, USNM 30053, R/ V Albatross, Northwestern Pacific Expedition , sta. 5080, west of Izu Islands, Honshu Island, Japan, 34˚10’30”N, 138˚40’E, 924 m, 19 Oct 1906 ; Paratype, USNM 30054, R/ V Albatross, Northwestern Pacific Expedition , sta. 5079, south of Omae Zaki, Honshu Island, Japan, 34˚15’N, 138˚E, 869–924 m, 19 Oct 1906 .

Diagnosis

Identical to P. recta (identical sclerites to Fig. 38 ), except the polyps are upwardly facing at 45˚ and roughly alternating in arrangement.

Distribution

This species is currently only known from Honshu Island, Japan, at depths of 869–924 m.

Remarks

The alternating polyps and a lack of keels on the marginal scales suggest that this species be placed within Plumarella , as suggested in Cairns (2011).

Comparisons

Without further material or knowing the importance of polyp orientation, we are hesitant to synonymise P. alternata and P. recta despite their identical sclerite and polyp sizes and shapes. This is in contrast to Cairns (2011), where these species are synonymised.

Figures

FIGURE 37. Plumarella alternata, holotype, USNM 30097: a) colony, approx. 16 cm long; b) close up of polyps. Plumarella recta, holotype, USNM 30040: c) colony 5.5 cm long; d) close up of polyps. Photos by RZG.

FIGURE 38. Plumarella recta, holotype, USNM 30040, identical sclerites to those of P. alternata: a) inner and b) outer surface of accessory operculars; c,d) inner and e) outer surface of opercular scales; f,g) inner and h) outer surface of marginal scales; i) outer and j,k) inner surface of body-wall scales; l) coenenchymal scales—first column of scales show the inner surface, remainder are the outer surface; m) lateral view of polyp; n) stereo opercular view of polyp. SEM taken by ZGR.