Lipotrapeza litusi O’Loughlin, 2012

O’Loughlin, P. Mark, Barmos, Shari & VandenSpiegel, Didier, 2012, The phyllophorid sea cucumbers of southern Australia (Echinodermata: Holothuroidea: Dendrochirotida: Phyllophoridae), Memoirs of Museum Victoria 69, pp. 269-308 : 275

Lipotrapeza litusi O’Loughlin sp. nov.

Figures 1c , 3

Material examined. Holotype. Western Australia, Cottesloe Beach , 32°00'S 115°45'E, beach washed, L. M. Marsh, Aug 1990, WAM Z13475 .

Diagnosis. Up to 70 mm long, 22 mm diameter (preserved, tentacles withdrawn); form cylindrical, upturned oral and anal rounded tapers; 20 tentacles, 5 outer pairs large, 5 inner pairs small; tube feet all around body, scattered dorsally, close ventrally, across introvert, diameters up to 0.7 mm; calcareous ring stout, irregular, with some short posterior composite projections arising jointly from radial and inter-radial plates, not tubular, lacking thin radial composite posterior elongations; short stone canal, madreporite close to vascular ring; single polian vesicles; thin branched gonad tubules arise in series along gonoduct on each side of dorsal mesentery.

Mid-body wall lacking ossicles; tube feet with endplates, support rods, abundant rosettes, few small plates; endplate diameters up to 536 µ m; support rods stout, distally enlarged and perforate, up to 144 µ m long; rosettes oval, up to 48 µ m long, intergrade with small plates; small plates irregular, perforate, denticulate margin, up to 104 µ m long; tentacles with rods and rosettes, rods stout, distally enlarged and perforate, up to 200 µ m long, abundant rosettes up to 64 µ m long.

Colour (preserved). Body off-white, body and tube feet with some residual red; tentacle trunks white, branches pale brown.

Distribution. Southwest Australia, Cottesloe beach, off-shore sediments.

Etymology. Named from the Latin litus (beach) with reference to the beach-washed source of the type specimen.

Remarks. Lipotrapeza litusi O’Loughlin sp. nov. is distinguished from other Lipotrapeza species in the key (above). The single specimen that this species is based on was found on a beach and the species presumably lives in off-shore sediments.

Figures

Figure 1. Photos of preserved type specimens. a, Lipotrapeza eichleri O’Loughlin sp. nov. (holotype NMV F174906); b, Lipotrapeza eichleri calcareous ring (paratype NMV F161502); c, Lipotrapeza litusi O’Loughlin sp. nov. (holotype WAM Z13475); d, Thyonidiella kungi O’Loughlin sp. nov. (holotype NMV F76637) (insert: form of the calcareous ring plates); e, Phyllophorella notialis O’Loughlin sp. nov. (holotype NMV F132691) (insert: form of the calcareous ring plates); f, Phyllophorella notialis calcareous ring (holotype).

Figure 3. SEM images of ossicles from holotype of Lipotrapeza litusi O’Loughlin sp. nov. (WAM Z13475). Tube foot endplate (top right), rosettes, endplate support rods, rare perforated plate (bottom right).