Psolus salottii, 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 : 30-31

Psolus salottii sp. nov.

Table 1 , Figures 5 a–f.

Material examined. Holotype. South Australia, Great Australian Bight, approximately 120 nautical miles due West of Cape Wiles, 34º56'S 133º19'E, trawled 772–820 m, FW Longva III, K. Gowlett-Holmes, 8 Nov 1989, SAM K2175.

Paratypes. Australia, North of Macquarie I., 52º59'36''– 53º00'30''S 159º59'48''– 160º00'36''E, epibenthic sled, 400–600 m, RV Southern Surveyor SS01/99, stn 129, CSIRO Fisheries Research Cruise, 31 Jan 1999, NMV F157397 (4).

Description. Psolus species up to 60 mm long, 40 mm wide and 20 mm high (damaged paratype, preserved); oval to circular form with domed profile, no oral or anal cone, lacking distinct oral or anal valves though 5 or more irregular, bluntly pointed oral scales present, with encroaching body wall scales; tentacles 10, 8 large, 2 small ventrally; thin, calcareous, coarsely granuliform body wall scales irregular in shape and arrangement, up to 10 mm long but variable in size and smaller on ventral margin; scales with macroscopically visible, low, dome-like lumps, slightly constricted at base, more evident laterally; non-calcareous parchment-like sole, bare mid-ventrally though tube feet extend variably at oral and anal ends onto the mid-ventral line; inner paired to zig-zag rows of larger tube feet and a peripheral band of sparsely placed and embedded, smaller tube feet.

Dorsal and lateral ossicles consist of large multi-layered ossicles (scales) up to 1.4 mm long, less common perforated plates with anastomosing secondary developments and multi-layering up to 0.9 mm long, and rare half cylinder perforated plates up to 144 µ m long and 72 µ m wide. Sole ossicles, rare, small, irregular single-layered plates with large round perforations often forming from cross-like initial plate of ~ 40 µ m; larger single-layered perforated plates up to 160 µ m long and 120 µ m wide, flat to curved with up to 13 irregular perforations and some blunt spines on margins. Largest tentacle ossicles up to 280 µ m long and variable in shape, thick to thin plates with multiple irregular perforations, some curved; some smaller dendritic branch endplates ~56 µ m long.

Colour (preserved). Off-white.

Distribution. South Australia, 34º56'S 133º19'E, 772–820 m (holotype only); southern ocean north of Macquarie I. 400–600 m (paratypes only).

Etymology. Named for Mark Salotti (Marine Invertebrates Section, Department of Aquatic Zoology, Western Australian Museum), in appreciation of his gracious assistance with echinoderm data and loan material from the Western Australian Museum.

Remarks. Psolus salottii sp. nov. is distinguished morphologically from other Australian Psolus species by a combination of: multiple irregular, bluntly pointed oral scales; large, conspicuous body wall scales with dome-like lumps; and the presence of perforated half-cylindrical ossicles dorso-laterally.

Figures

FIGURE 5. Psolus salottii sp. nov. holotype (a, b, c, d in part, e, SAM K 2175): a, dorsal view; b, lateral view; c, ventral view; d, sole ossicle (larger curved plate from holotype, others from paratype); e, dorsal ossicles (multi-layered scales and perforated cylinders); paratype (d in part, f, NMV F 157397): d, sole ossicles (3 smaller ossicles from paratype); f, tentacle ossicles, including end plates.