Pseudostichopus tuberosus, 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 : 176-177

Pseudostichopus tuberosus sp. nov.

Figures 9b, f , 10i , 11g, h , 12i–l

Material examined. Holotype. North Pacific Ocean, off Oregon, 45°43'N, 125°13'W, 1920 m, Commando , 28 May 1964, USNM E16721 .

Paratypes. Holotype locality and date, USNM 1008333 (1); NMV F101864 (1) .

Other material. North Pacific Ocean , off southern California, 32°33'N, 118°04'W, 1937 m, USNM E17015 (1).

Description. Up to 140 mm long; body wall leathery, thin, firm; body flat ventrally, convex dorsally; prominent single series of ventrolateral protuberances (“warts”), irregularly rounded, typically 2.0 mm wide, domed, soft and thin-walled, or firm and flat, not surmounted by papillae, ventral to series of ventrolateral papillae; body transversely creased and wrinkled ventrally, sometimes dorsally, abundant grit attachments, ventrolateral margin with indentations and lobes created by transverse creases; irregular double rows of tapering papillae on both paired radii, up to 2.0 mm long; minute tube feet all over body, up to 0.2 mm long; ossicles in tentacles and gonad; tentacle ossicles abundant, predominantly small thick to thin curved rods, bluntly to finely spinous or smooth, swelling mid-rod sometimes, rare short branches, rods up to 340 µm long; gonad ossicles abundant, small unbranched rods, tapering to pointed ends, slightly spinous to smooth, typically with central swelling, up to 140 µm long.

Colour. Body, tube feet and protuberances off-white.

Etymology. From the Latin tuberosus (“full of lumps or protuberances”), referring to the distinct large protuberances along each ventrolateral margin.

Distribution. North-eastern Pacific Ocean, off Oregon and southern California, 1920–1937 m.

Remarks. The ventrolateral protuberances are wart-like ("fungiform papillae"), and resemble similar features in Bathyplotes moseleyi . Amongst Pseudostichopus species the distinguishing characters of P. tuberosus are: ventrolateral series of wart-like protuberances; presence of small unbranched tapered rods in the gonad.

Figures

Figure 9. Characters of Pseudostichopus. a, drawing of transverse section of mid-body (as in P. mollis); b, cylindrical longitudinal muscles detached from calcareous ring (P. tuberosus sp. nov., NMV F101864, paratype); c, dorsolateral radial papillae (P. elegans, NMV F97447, papillae up to 8 mm long); d, drawing of part of gonad, unbranched tubules, arising separately along gonoduct; e, two series of unbranched gonad tubules along gonoduct (P. mollis, TM H2004); f, gonad (P. tuberosus sp. nov., paratype, USNM 1008333).

Figure 10. a, Pseudostichopus hyalegerus, sponge spicule cover (P. japonensis, paratype, SMBL 314, junior synonym, 29 mm long). b–c, P. mollis; b, rugose ventrum (TM H3111, 145 mm long); c, calcareous ring (TM H2004). d–e, P. papillatus (RAS, syntype, 27 mm long); d, dorsal view of paired radial tubercles; e, ventrolateral view, tube feet. f–h, P. peripatus; f, ventral view, marginal tubercles, grit attachment, transverse creases (NMV F101840, 60 mm long); g, ventral view, marginal tubercles, grit attachment, transverse creases (NMV F101839, 45 mm long); h, cylindrical muscles (arrows), gonad tubules (P. tuberculatus, holotype, OMNH Iv1190, junior synonym). i, P. tuberosus sp. nov. (USNM E16721, holotype, 115 mm long), ventral view, lateroventral tubercles (arrow).

Figure 11. Tentacle ossicles (SEM). a–b, Pseudoshichopus aemulatus (USNM 1025525, paratype). c–d, P. elegans (USNM E16505). e–f, P. mollis (USNM E48656). g–h, P. tuberosus sp. nov. (USNM E16721, holotype). i–l, P. peripatus, i (USNM 12198), j (USNM E38794), k (USNM E38796), l (USNM E49349).

Figure 12. Gonad ossicles (SEM). a–d, Meseres villosus (USNM E9929). e–f, M. translucens sp. nov. (USNM E48652, holotype). g–h, Pseudostichopus peripatus, g (USNM 12198), h (USNM E48638). i–l, P. tuberosus sp. nov. (USNM E16721, holotype). m, P. aemulatus (USNM 1025525, paratype). Posterior lobe ossicles (compound microscope). n–p, P. hyalegerus, n–o (NMV F80181), p (NMV F80178). Tentacle ossicles (compound microscope). q–t, M. ustulatus sp. nov. (NMV F101858, paratype).