Psolidium marshae, O’Loughlin & Ahearn, 2008

O’Loughlin, P. Mark & Ahearn, Cynthia, 2008, Australian species of Psolidium Ludwig (Echinodermata: Holothuroidea: Psolidae), Memoirs of Museum Victoria 65, pp. 1-22 : 15-16

Psolidium marshae sp. nov.

Table 1 , Figures 1d , 3a , 6d–f

Material examined. Holotype: Western Australia, Cape Naturaliste, Geographe Bay, Bunker Bay , granite reef, brown algae canopy, Cystophora , 33°32.152'S 115°01.993'E, 5.4 m, A. Sampey, 15 Apr 2005, WAM Z31173 .

Paratype: Eagle Bay, granite reef, brown algae canopy, Sargassum , Cystophora , 33°33.387'S 115°04.078'E, 4.9 m, A. Sampey, 2 Feb 2005, Z31165 (1).

Other material. South Australia, Kangaroo I, b/wn Western River Cove and Snug Cove, 12–14 m, under rock, on coralline red alga or sponge , K. L. Gowlett-Holmes, 14 Mar 2004, SAM K2173 (1, live colour photo SAM PK0273 ) .

Description. Psolidium species up to 10 mm long (preserved); very uneven surface; dorsal and lateral scales thick, up to 1.5 mm wide; oral and anal scales small, tapering to rounded end distally.

Sole with peripheral band of tube feet, band up to 4 wide, size variable, outermost series slightly smaller; mid-ventral radial series irregular, up to 4 wide; peripheral series of tube feet variably continuous anteriorly and posteriorly.

Dorsal and lateral ossicles: multi-layered ossicles (scales) thick, tube foot canals; buttons numerous, thick, smooth, not knobbed, irregularly oval, 3-9 perforations, up to 216 μ m long; crosses small, deeply cupped, most quadri-radiate, some tri- or penta-radiate, abundant, typically 32 μ m long, arms distally spinous, spinelets long, spinelets sometimes joined to close rim to form cups; rosettes abundant, oval, typically 32 μ m long.

Sole ossicles: knobbed plates numerous, variable form, 4-16 perforations, thickly knobbed on surface and marginally, up to 240 μ m long; cups and cupped crosses shallow concave, with digitiform spinelets marginally only; cups and cupped crosses of 2 sizes, larger typically 72 μ m long, of variable form, some intergrading with knobbed plates, smaller typically 32 μ m long, quadri-radiate or tri-radiate base, marginal rim closed or not.

Tentacle ossicles include abundant rosettes, oval, up to 56 μ m long.

Colour. Live. Predominantly white with some brown patches.

Preserved: dorsally and laterally off-white with dark brown-black patches and flecks; sole off-white; tentacle trunks with dark brown markings.

Distribution. Western Australia, Cape Naturaliste, Geographe Bay; granite; 5 m; South Australia, Kangaroo I; 12– 14 m.

Etymology. Named for Loisette Marsh (Research Associate, Marine Invertebrates Section, Department of Aquatic Zoology, WesternAustralian Museum),in appreciation of her considerable contribution to echinoderm systematic and biogeographical research, and with gratitude for her gracious assistance with loans of echinoderm specimens for systematic research.

Remarks. The distinctive characters of Psolidium marshae sp. nov. are the presence of 2 size ranges of cupped crosses and cups in the sole, and presence of rosettes in the body wall.

Figures

Figure 1. Photos of live specimens of Psolidium Ludwig, 1886 (a–d, in situ by K.Gowlett-Holmes; e, in aquarium by L.Altoff):a, P. granuliferum H. L. Clark, 1938, Port Davey, Tasmania (14 mm long preserved; SAM K2174, PK0259); b, P. karenae sp. nov., Yorke Peninsula, South Australia (17 mm long preserved; holotype SAM K2177, PK0105); c, P. laperousazi sp. nov., Kangaroo I, South Australia (13 mm long preserved; paratype SAM K2179, PK0253); d, P. marshae sp. nov., Kangaroo I (10 mm long preserved; SAM K2173, PK0273); e, P. ravum Hickman, 1962, Portland, Victoria (17 mm long preserved; NMV F125379).

Figure 3. Photos of preserved specimens of Psolidium Ludwig, 1886 (by L. Altoff): a, P. marshae sp. nov., Geographe Bay, Western Australia (dorsal view; 8 mm long; holotype WAM Z31173); b, P. mccallumae sp. nov., slope off Point Cloates, Western Australia (lateral view; 7 mm long; holotype NMV F126891); c–d, P. nigrescens H. L. Clark, 1938, Gunnamatta Bay, New South Wales (40 mm long; AM J6821); c, lateral view; d, ventral view (sole); e–f, P. parmatus (Sluiter, 1901), Adele slope, Western Australia (9 mm long; NMV F151835); e, lateral view; f, ventral view (sole).

Figure 6. Photos of ossicles from Australian species of Psolidium Ludwig, 1886 (by Mark O’Loughlin and Chris Rowley): a, P. granuliferum H. L. Clark, 1938, multi-layered ossicles from the sole (SAM K2174); b–c, P. laperousazi sp. nov. (paratype SAM K2179); b, dorsal partly closed cup; c, cup and plate from sole; d–f, P. marshae sp. nov. (paratype WAM Z31165); d, dorsal small cupped crosses and rosettes; e, large cup and knobbed plate from sole; f, dorsal buttons, small endplate, large and small cupped crosses and rosette.