Pseudostichopus spiculiferus ( O’Loughlin, 2002 ) O'Loughlin & Ahearn, 2005

O'Loughlin, P. Mark & Ahearn, Cynthia, 2005, A review of pygal-furrowed Synallactidae (Echinodermata: Holothuroidea), with new species from the Antarctic, Atlantic and Pacific oceans, Memoirs of Museum Victoria 62 (2), pp. 147-179 : 176

Pseudostichopus spiculiferus ( O’Loughlin, 2002) comb. nov.

Figure 1g

Pseudostichopus sp. MoV 2068.— O’Loughlin et al., 1994: 253–255.

Meseres spiculiferus O’Loughlin, 2002: 309–312 , figs 1a–f, 2a–d, tables 1–3.

Material examined. (See O’Loughlin, 2002). Antarctic Ocean , Weddell Sea, 1554 m, USNM 49279 (1) ; Antarctic Peninsula , 370–375 m , E48582 (1); 246–270 m, E49242 (2); 326 m, 49258 (2); 460–500 m, E49472 (4); Ross Sea , 73°58'– 78°23'S, 168°50’E – 161°57'W, 364–728 m , E48598 (2); E48643 (2); E49268, E49269 (7); 1005124 (1); E49287 (2); E49354 (1); E49358 (2); 485–490 m, 1005121 (4); 1005123 (3); New Zealand, Antipodes Is , 2010–2100 m , 1005113 (1).

Description. Up to 105 mm long; body typically encrusted with sponge spicules, sometimes globigerines; body flat ventrally, convex dorsally; lateroventral margin subacute, some reticulate ridges with small digitate projections, lacking prominent ventrolateral projections; irregular double rows of tube feet dorsolaterally, larger along ventrolateral margin in band up to 5 irregular rows wide and continuous around anterior body, sometimes contiguous, up to 3.0 mm long, 0.8 mm diameter; ossicles in tentacles, tube feet and gonad; tentacle ossicles thick to thin, curved to straight irregular rods, frequently swollen mid-rod, rarely swollen terminally, rarely branched, rarely bluntly spinous, up to 320 Μm long; tube feet with rods distally, same form as tentacle rods, up to 200 Μm long; “endplates” of close cluster of irregular rods, up to 130 µm wide; gonad ossicles abundant smooth rods, tapered to points at ends, variable shape, frequently with central swelling, X- or Yshaped or complex multiple branching, branches sometimes joined to create large perforations, ossicles frequently 120 Μm long, up to 300 Μm long.

Colour. Body off-white or grey or grey-brown; tube feet off-white to reddish-brown.

Distribution. Eastern Antarctica, off Wilkes, MacRobertson, Enderby Lands, 177–695 m ( O’Loughlin, 2002); Ross Sea, 364–728 m; Antarctic Peninsula, 246–500 m; Weddell Sea, 1554 m; New Zealand, Antipodes Is, 2100 m.

Remarks. Meseres spiculiferus has the diagnostic characters of Pseudostichopus above, and is reassigned. The above data extend the distribution of O’Loughlin (2002) from eastern Antarctica to the Weddell Sea and New Zealand Antipodes Is, and depth to 2100 m. Amongst Pseudostichopus species, the distinguishing characteristics of P. spiculiferus are: dense cover of sponge spicules; absence of large pygal lobe ossicles; lateral band of tube feet; complex branching gonad ossicles.

Figures

Figure 1. Characters of pygal-furrowed Synallactidae. a, ventral mouth and anus (M. helios sp. nov., USNM E31104, paratype, 91 mm long); b, ventral peltate tentacles, polian vesicle (P. mollis, TM H2004; anterior end dissected off); c, respiratory tree (P. mollis, TM H2004); d, drawing of dorsal posterior pygal furrow; e, posterioventral view of pygal furrow and anus (M. violaceus, BMNH 86.10.2.150); f, anterior dorsal madreporite (arrow) (P. peripatus, USNM 1008159); g, drawing of calcareous ring (radial plate right, as in P. spiculiferus); h, calcareous ring (M. crinitus sp. nov., USNM E48644, paratype); i, calcareous ring (M. violaceus, BMNH 86.10.2.145).