Psolidium oloughlini, Mackenzie, Melanie & Whitfield, Emily, 2011

Mackenzie, Melanie & Whitfield, Emily, 2011, An overview of the Australian psolid sea cucumbers (Echinodermata: Holothuroidea: Psolidae) with the description of 5 new species, Zootaxa 3037, pp. 21-36 : 26

Psolidium oloughlini sp. nov.

Table 1 , Figures 2 a–f.

Material examined. Holotype. Australia, Tasmania, King I., Currie Harbour, below Golf Course, 39º56'S 143º51'E, Marine Study Group, 10 Mar 1980, NMV F169347.

Paratypes. Type locality and collection date, NMV F169348 (2).

Description. Psolidium species up to 21 mm long, 8 mm wide, 8 mm high (holotype, preserved); elongate in form and curved ventrally creating a high vertical profile; no discrete oral or anal valves, multiple oral scales in layers, thickened and digitiform with a mostly granular surface except for tip which is smooth and lighter in colour, anal scales are thinner than oral or body wall scales; tentacles 10, 8 large, 2 small ventrally; large, irregular dorsolateral scales up to 4 mm long with coarsely granuliform surface and macroscopically visible low-pointed spires, ventral margin scales smaller and less conspicuous at 1–2 mm in length, body wall scales strongly imbricated dorsally; dorso-lateral tube feet macroscopically inconspicuous; transparent sole, bare mid-ventrally, surrounded by roll of skin and a single series of large withdrawn tube feet separated from ventral margin by up to 2 mm of ribbed skirting, series of smaller withdrawn tube feet towards the ventral margin.

Large dorso-lateral multi-layered ossicles (scales) up to 1.3 mm long and 0.8 mm wide, or up to 256 µ m long and 190 µ m wide when tube foot canals are present, and variably with up to two tall (40 µ m) spinous spires, distally digitiform; tube foot support plates and end plates also present dorso-laterally. Sole ossicles include singlelayered flat perforated plates variably thick or thin, knobbed or smooth up to 168 µ m long; flat-bottom bowls up to 176 µ m long with perforations, and blunt, spinous edges; smaller tube foot end plates.

Colour (preserved). Off-white

Distribution. Australia, Tasmania, King I., Bass Strait; shallow sub-littoral zone.

Etymology. Named for P. Mark O’Loughlin (NMV Honorary Associate) in recognition of his initial research into the Australian Psolidae , which was of great assistance in this paper, and his significant ongoing contribution to holothuroid taxonomy and research.

Remarks. Psolidium oloughlini sp. nov. appeared initially to be a species of Psolus as the dorsal and lateral tube feet were not evident. Microscopic examination of ossicles revealed the tube foot canals and end plates of a Psolidium . It is distinguished from other Australian Psolidium species by a combination of: a greater number of oral scales; wide, ridged skirting surrounding the sole; the presence of spinous spires on many of the multi-layered dorso-lateral ossicles; the presence of flat-bottom bowls with blunt, spinous edges in the sole.

Figures

FIGURE 2. Psolidium oloughlini sp. nov. holotype (a – c, NMV F 169347): a, dorsal view; b, lateral view; c, ventral view; paratype (d – f, NMV F 169348): d, sole ossicles; e, dorsal scales with spires and perforations for tube feet (insert – tip of spire); f, dorsal tube foot support plates.