Paragorgia aotearoa, 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 : 44-47

Paragorgia aotearoa sp. nov.

( Figs. 28–29 )

Material examined. Holotype: NIWA 3325, H­845, J206, 42°50.26’– 42°49.99’S, 176°54.96’– 176° 55.17’W, “Mt Muck seamount” 700–900 m, August 1996, (RV Tangaroa 9609/40, bottom trawl, col. D. Tracey).

Diagnostic characters. Medulla with ornate but smooth and blunt spindles usually less than 0.3 mm in length. Surface of the cortex, including autozooid aperture, with comparatively (among Paragorgia spp.) large 8­radiate sclerites up to 0.09 mm.

Description. Profusely branching colonies up to 230 mm in length (holotype) with terminal branches down to 3–4 mm in diameter ( Fig. 28 A). Numerous short, lateral branches arise from the main branches with an irregular but clavate appearance ( Fig. 28 A). Autozooid (and siphonozooid) polyps located towards one side of the colony ( Fig. 28 B) whereas the other side has only siphonozooids ( Fig. 28 C). There is a regular trend for the autozooids to form clumps, but many autozooids are several millimeters apart from each other. Cortex red and thick (~> 0.5 mm) containing siphonozooids fairly uniformly­distributed ~ 0.5 mm apart. Medulla perforated by 3–4 main axial canals at terminal branches, usually surrounded by red sclerites. Autozooid polyp tentacles with blunt ovals, slightly thicker than in most Paragorgia spp., up to 0.1 mm in length and 0.5 mm width, regularly and profusely ornate with conical tubercles ( Fig. 29 A–C). Surface of the cortex, including autozooid aperture, with comparatively (among Paragorgia spp.) large 7­ to 8­radiate sclerites up to 0.09 mm averaging 0.076 mm in length (0.008 SD, n=10) ( Fig. 29 D–F). Rays nearly symmetrical with smooth surfaces but occasional lobulated ( Fig. 29 D–F). Surface radiates between 1.65 times longer than wider, averaging 0.04 mm in width (0.004 SD, n=10). Medulla with ornate (red and colorless) but smooth and blunt spindles up to 0.33 mm in length averaging 0.28 mm (0.03 SD, n=10) ( Fig. 29 G). Holotype with a commensal white anemone.

Morphological variation. Unfortunately, it is not possible to make specimen comparisons since only one specimen of P. aotearoa sp. nov. was available. Overall, intracolonial variation of sclerites and other features is very low, with rather low variation in surface radiates: a character where most of the variation in form is present in Paragorgia spp.

Distribution. Only known for the type location, Chatham Rise between the New Zealand’s North Island and the Chatham islands.

Species comparisons. Some features of P. aotearoa closely resemble P. johnsoni Gray and P. re g a l i s Nutting. For instance, the sclerites from the cortex surface are chiefly 8­radiates with smooth but slightly lobate radial ornamentation ( Figs. 17 D–F; 18B) (see also Bayer, 1956: Fig. 1 ). However, the diagnostic character of P. aotearoa , short medullar sclerites up to 0.3 mm, are surpassed by P. regalis with spindles up to 0.4 mm ( Fig. 27 C). In addition, P. re g a l i s colonies are salmon pink (Bayer, 1956; pers. obs.) with larger branches and polyps (autozooids/siphonozooid) (e.g., Fig. 13 ). The surface sclerites of P. aotearoa are very similar in shape to the surface sclerites of P. johnsoni ( Fig. 10 C–F). However, P. aotearoa sclerites are clearly larger than those of P. johnsoni (0.08 vs 0.05 mm in average respectively); in fact, P. aotearoa has the largest surface sclerites in all species of Paragorgia . Autozooid polyp sclerites of P. johnsoni also differ from those of P.

aotearoa in the irregular ornamentation. Nonetheless, the phylogenetic affinity between P. regalis , P. johnsoni , and P. aotearoa is clear.

Etymology. The word Aotearoa means in Maori, “the land of the long white cloud” as the first Maori settlers called what is today known as New Zealand.

Figures

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

FIGURE 10. Paragorgia johnsoni Gray (USNM 73767): A, stereo pair of a sclerite from the autozooid polyps (scale 10 m); B, additional sclerites from the autozooid polyps (scales 20 m); C – F, radiate sclerites (C – D are stereo pairs) from the colony surface (scales 10 m); F, additional sclerites from the colony surface and intermediates towards the medulla (scales 10 m); G, sclerites from the colony medulla (scales 100 m); H, sclerites from the subsurface / outer medulla (scales 20 and 30 m).

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

FIGURE 17. Paragorgia alisonae sp. nov.: A – B, holotype (NIWA 3312); C – D, paratypes (NIWA 3316 – 3317 respectively). Calliper opened at 2 cm.

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

FIGURE 28. Paragorgia aotearoa sp. nov., holotype (NIWA 3325): A, whole colony; B, branch detail apolypar side; C, polypar (autozooid) side (calliper open at 20 mm).

FIGURE 29. Paragorgia aotearoa sp. nov., holotype (NIWA 3325): A – B, stereo pairs of the sclerites from the polyps (scale 10 m); C, additional sclerites from the polyps (scales 20 and 10 m); D – F, radiate sclerites from the colony surface (scales 10 m) (E and F are stereo pairs); G, sclerites from the colony medulla (scales 20 m).