Psolidium berentsae, 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 : 13

Psolidium berentsae sp. nov.

Table 1 , Figures 2a , 5a–c

Material examined. Holotype: Queensland, Lizard I., off western side of Palfrey I., washings from coral blocks, 14°40'S 145°28'E, 6 m, P. B. Berents and P. A. Hutchings, 12 Jan 1976, stn 76 LIZ 16B, AM J24098 .

Paratypes: type locality and date, J24099 (2); type locality and date, stn 76 LIZ 16A, J24100 (1).

Other material (up to 6 mm long; no cups detected): Chinamans Head, washings from coral blocks, 14°36'S 145°37'E, 6 m, P. A. Hutchings and P. B. Weate, 10 Jan 1976 , stn 76 LIZ 15, J24101 (1); off Chinamans Head , reef rock, 14°40'S 145°28'E, 7 m, P. A. Hutchings and P. B. Weate, 27 May 1976 , stn 76 LIZ B-00-03-3, J24102 (1); No Name Reef , southwest end, rubble from base of bommie, 14°40'S 145°39'E, 15 m, I. Loch, 19 Dec 1984, J24106 (1).

Other material (up to 11 mm long; no ossicles; presumably initial formalin preservation): Lizard I, off Chinamans Beach, coral block, 14°40'S 145°28'E, 7 m, P. A. Hutchings, Apr 1978, stn D15-27-1, J24104 (1); Outer Yonge Reef, 14°37'S 145°38'E, 18 m, P. A. Hutchings, 15 Jan 1977, stn 77 LIZ 47-4, J24105 (3).

Description. Psolidium species up to 12 mm long (preserved); body rounded in transverse section ventrally; dorsal and lateral scales thick, up to 1.3 mm wide; oral, anal and mid-body scales frequently tapering to projecting, bluntly pointed distal end, body surface very uneven.

Sole with peripheral band of tube feet, outer single series of slightly smaller tube feet, inner series 2 wide; mid-ventral radial series 2 wide; sole not discrete in very small specimens (4-6 mm long), small scales conspicuous.

Dorsal and lateral ossicles: multi-layered ossicles (scales), thick, with tube foot canals; buttons numerous, perforated, thick, irregularly oval, thickly knobbed, up to 176 μ m long, up to 12 perforations, intergrade with multi-layered ossicles; in larger specimens (12 mm long) cups numerous, deeply cupped, thick cruciform base, rim bluntly spinous, cups sometimes “bridged” with transverse branches from rim joined, cups 56–96 μ m long; in small specimens (4–6 mm long) numerous thin cupped crosses and cups, with elongate pointed spines on rim, cups up to 80 μ m long; rosettes numerous in larger specimens, densely branched, irregularly oval in form, up to 56 μ m long.

Sole ossicles: numerous knobbed plates, elongate, irregular in shape, large marginal and surface knobs, 3-12 perforations, up to 240 μ m long; rare smooth elongate, perforated plates, up to 240 μ m long.

Tentacle ossicles include abundant rosettes, densely branched, up to 40 μ m long.

Colour (preserved). Dorsal and lateral dark to pale brown, sometimes with brown flecking; sole off-white; tentacle trunks brown, dendritic branches off-white; introvert off-white.

Distribution. Queensland, Lizard I, 14°36'– 14°40'S 145°28'– 145°39'E, coral rocks and rubble; 6– 18 m.

Etymology. Named for Dr Penny Berents (Scientific Officer, Marine Invertebrates, Australian Museum), with appreciation of her contribution to Australian marine invertebrate research, and with gratitude for her gracious assistance with loans and research in the Australian Museum.

Remarks. Some of the paratype specimens are small, 4 mm long ( J24099 (2)). In this material the cups and cupped crosses are much finer than in the larger type material. This is judged to be a developmental difference. Some of the non-type specimens assigned to the new species are small, with specimen lengths 4 mm ( J24101 ), 5 mm ( J24102 ) and 6 mm ( J24106 ). No cups or cupped crosses were detected, and this was judged to be a sampling inadequacy for this very small material, since fine cups and cupped crosses were found in 4 mm long paratype. The specimens have the same appearance as the types, and are from the type locality and eco-niche. Further collecting and study might reveal the presence of an additional species.Other additional material judged to be P. berentsae sp. nov. has the body form and scale outlines of the species, but lacks calcareous material.The preservation history presumably included time in acidic formalin solution. Specimen lengths are 5 mm ( J24104 ) up to 11 mm ( J24105 ). A rounded ventrum, absence of discrete sole and presence of conspicuous scalesventrallyappeartobejuveniledevelopmentalcharacteristics. The distinguishing characters of P. berentsae sp. nov. are the tapered body scales, rounded ventrum, fine cups with long pointed spines in small specimens, and thick cups with blunt spines and sometimes “bridges” in large specimens.

Figures

Figure 2. Photos of preserved specimens of Psolidium Ludwig, 1886 (a, c–d by L. Altoff; b, e–f by S. Hinkley and D. Maric): a, P. berentsae sp. nov., Lizard I, Queensland (lateral view; 12 mm long; holotype AM J24098); b, P. granuliferum H. L. Clark, 1938, Smokey Bay, South Australia (dorso-lateral view, with mouth left; 19 mm long; SAM K2176); c–d, P. hutchingsae sp. nov., Split Solitary I, New South Wales (20 mm long; holotype AM J24107); c, dorso-lateral view; d, 10 tentacles, with 2 small ventral ones bottom; e, P. karenae sp. nov., Adelaide (lateral view, mouth left; 20 mm long; paratype SAM K2185); f, P. laperousazi sp. nov., D’Entrecasteaux Channel, Tasmania (dorso-lateral view, mouth right; 18 mm long; paratype SAM K2339).

Figure 5. Photos of ossicles from Australian species of Psolidium Ludwig, 1886 (by Mark O’Loughlin and Chris Rowley): a–c, P. berentsae sp. nov.; a, dorsal cupped crosses and cups (small specimen, paratype AM J24099); b, dorsal bridged cup (holotype AM J24098); c, dorsal cups and rosettes (holotype AM J24098); d–f, P. hutchingsae sp. nov.; d, dorsal cupped cross (paratype AM J24108); e, dorsal multi-layered ossicle (scale) with tube foot canals (AM J19665); f, tentacle plate and rosettes (AM J19665).