Paragorgia maunga, 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 : 41-44

Paragorgia maunga sp. nov.

( Figs. 26–27 )

Material examined. Holotype: NIWA 3322, H­844, J210, Z10989 , 33° 53.2’S – 167° 56.3’E, “Wanganella Bank” 1082 m, 22 January 2002 (col. S. Smith, F/V Waipori, bottom trawl).

Paratypes: NIWA 3323, P­1403, J223, Z9779, 34° 0 7.1–07.55’S–174° 53.7–54.0’E, “Seamount #441” 808–1121 m, 25 June 1999 (col. C. Blincoe, FV Seamount Explorer 1236/26, bottom trawl); NIWA 3324, P­1404, J67, 35° 43.71' S, 178° 29.98' E, “Rumble III seamount”, 545–671m, 3 November 2000 (RV Kaharoa 0011/28, epibenthic sled).

Diagnostic characters. Delicate, soft, red cortex. Medulla perforated by only 2–3 small axial canals, densely surrounded by red sclerites; numerous even smaller canals throughout. Surface sclerites with an asymmetrical enlargement of most radial ornaments generating smoothly lobulated sub­ornaments in all rays.

Description. Colonies with a delicate, thin, soft, red cortex; all examined material partially eroded exhibiting the white medulla on surface. The holotype is a fragmented colony 210 mm in length ( Fig. 26 ); the paratypes are broken fragments less than 120 mm long. Branching possibly pseudo­dichotomous in one plane (no complete specimens available), with autozooid polyps towards one face. Autozooids forming irregular clumps of 3–5 polyps ( Fig. 26 B). Slimmer parts of branches down to 2–3 mm width. Medulla perforated by only 2–3 main small canals, tending central, and numerous even smaller canals in both the medulla and subsurface/outer medulla. Center of the medulla, around the main canals, with red sclerites, otherwise colorless with occasional red ones. Autozooid tentacles exhibiting the common red Paragorgia sclerites: ornate ovals up to 0.1 mm in length with conical ornaments throughout ( Fig. 27 A–C, J). Surface of the cortex, including autozooid aperture, with small, radiate sclerites up to 0.08 mm in length averaging 0.06–0.07 mm (0.006 SD, n=10, NIWA 3322=3324) ( Fig. 27 D–H, K). Surface radiates between 1.7–1.8 times longer than wide, averaging 0.04 mm in width (0.004 SD, n=10, NIWA 3322=3324). Asymmetrical enlargement of most radial ornaments generating smoothly lobulated sub­ornaments in all rays ( Fig. 27 D–H, K). Medulla with long, straight, ornamented (occasional large, irregular projections) spindles up to 0.35 mm in length ( Fig. 27 I).

Morphological variation. There were some small (<0.01 mm) but significant differences in the size of surface sclerites of two specimens (t=5.5, df=19, P <0.001, only 10 sclerites measured in each specimen) although no variance differences were found among the specimens (F=0.8, df=9, P>0.4). Since there is an expected variation in the surface sclerites, i.e., progressively larger towards the subsurface, and the examined specimens were highly eroded during the collection, the differences among specimens could be due to differential sampling in relation to the surface­subsurface. Nonetheless, all examined specimens clearly exhibit the species diagnostic characteristics (e.g., Fig. 27 A–I vs. J–K).

Distribution. The three specimens examined span a large area of the EEZ of New Zealand from the West Norfolk ridge to two seamounts North off the Bay of Plenty ( Fig. 1 ).

m); K, radiate sclerites from the colony surface (scales 10 m).

Species comparisons. Externally and in the shapes of the surface sclerites, P. maunga sp. nov. resembles P. kaupeka , and a close phylogenetic relationship is expected among these two species. However, it is rather easy to tell them apart by comparing their diagnostic characters. The form of the surface radiate sclerites can seem nearly identical under the light microscope but there is nearly 0.03 mm difference in the mean length of the two species’ sclerites, which can be determined using a micrometer and compound microscope. Under SEM it is also evident that the enlargement of the radial ornamentation in the surface sclerites of P. kaupeka is greatly irregular, generating a fairly rough surface, whereas in P. maunga it is smooth and lobate.

Etymology. The word maunga means “mount” in Maori, alluding to the collection of specimens from seamounts.

Figures

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

FIGURE 26. Paragorgia maunga sp. nov., holotype (NIWA 3322): A, whole colony; B, branch detail (calliper open at 20 mm).

FIGURE 27. Paragorgia maunga sp. nov., A – I, holotype (NIWA 3322): A, stereo pair of a sclerite from the polyps (scale 10 m); B – C, additional sclerites from the polyps (scales 10 and 20 m); D – H, radiate sclerites (D – G stereo pairs) from the colony surface (scales 10 m); I, sclerites from the colony medulla (scales 100 m). J – K, Paratype (NIWA 3324): J, sclerite from the polyps (scale 30