Paracaudina keablei O’Loughlin and Barmos, 2011

O'Loughlin, P. Mark, Barmos, Shari & VandenSpiegel, Didier, 2011, The paracaudinid sea cucumbers of Australia and New Zealand (Echinodermata: Holothuroidea: Molpadida: Caudinidae), Memoirs of Museum Victoria 68, pp. 37-65 : 56

Paracaudina keablei O’Loughlin and Barmos sp. nov.

Figures 11c , 14

Material examined. Holotype. Queensland, Moreton Bay, Stradbroke Island , Dunwich, sandbar, H. Silver, 2 Dec 1978, AM J13579 .

Other material. Queensland, Gulf of Carpentaria, SE corner, 17º24'55''S 140º42'35'' E, 4.6 m, CSIRO Rama prawn survey trawl stn 555, 16 Jan 1964, AM J17085 (1) ; 17º30'15''S 140º40'10'' E, 2.3 m, CSIRO Rama prawn survey trawl stn 494, 18 Dec 1963, AM J17051 (3).

Diagnosis. Paracaudina species up to 75 mm total length, diameter up to 18 mm, caudal taper and short discrete tail 25 mm long (preserved); body wall firm, not thin, smooth to wrinkled, partly transversely creased, slightly rugose, off-white (preserved); short caudal taper and discrete thin tail; no evidence of phosphatising; mid-body ossicles predominantly thin-walled octagonal plates with large central perforation, basal box with 4 supporting arms bridging one side of ossicle, cross with 4 supporting arms bridging outer side, short blunt spines only around marginal surface and on cross, not on box, lacking prominent marginal sub-digitiform projections and knobs, ossicles up to 70 µm across.

Type locality. Northeast Australia, Moreton Bay .

Distribution. Northeast Australia, Moreton Bay, Stradbroke Island, Gulf of Carpentaria; 0– 5 m.

Etymology. Named for Dr Stephen Keable, Collection Manager, Marine Invertebrates (Natural Science Collections), Australian Museum, in appreciation of his prompt and gracious assistance with loans from the Australian Museum for this and other research projects.

Remarks. The holotype specimen of Paracaudina keablei O’Loughlin and Barmos sp. nov. is damaged, but the ossicles are in good condition. The ossicles in the additional material are somewhat eroded, but the predominant ossicle form is diagnostically distinguishable. Four Paracaudina Heding species have a predominant ossicle form of octagonal plates with a basal box with four supporting arms bridging the ossicle on one side and a cross with four supporting arms bridging the ossicle on the opposite side. The predominant ossicle form in Paracaudina chilensis (Müller) is of moderate thickness with prominent knobs and sub-digitiform projections around the margin. The predominant ossicles in Paracaudina coriacea (Hutton) are thick buttons with rounded margin and small perforations. Parcaudina keablei sp. nov. is distinguished from both these species by having a predominant ossicle form of thin-walled plates with large perforations and lack of prominent marginal projections. The ossicles in Paracaudina delicata Pawson and Liao, 1992 are also thin-walled, but have numerous fine digitiform projections around the margin. Paracaudina keablei is further distinguished from the other three species mentioned here by having a short thin tail.

Figures

Figure 11. Photos of preserved specimens of species of Paracaudina (a, c–f): a, P. cuprea O’Loughlin and Barmos sp. nov. holotype (NMV F157396); b, photo of live specimens of P. cuprea including holotype (photo by P. Vafiadis); c, P. keablei O’Loughlin and Barmos sp. nov. holotype (AM J13579); d, P. luticola Hickman, 1962 (NMV F169342); e, P. tetrapora (H. L. Clark, 1914) (from Merricks, Westernport Bay, Victoria; NMV F76565); f, P. tetrapora (H. L. Clark, 1914) (from off Glenelg, South Australia; AM J24918).

Figure 14. SEM images of ossicles from the mid-body wall of the holotype specimen of Paracaudina keablei O’Loughlin and Barmos sp. nov. from Dunwich, Stradbroke Island, Moreton Bay, Queensland (AM J13579).