Psolus macquariensis, Davey, 2013

Davey, Nicola, 2013, The Psolidae of New Zealand and some additions to the Macquarie Ridge fauna (Echinodermata: Holothuroidea: Psolidae), Memoirs of Museum Victoria 70, pp. 51-67 : 55

Psolus macquariensis sp. nov.

http://zoobank.org/urn:lsid:zoobank.org:act:B0AC4334-A7DF-

4548-B5DB-D33715DB5A09

Table 1, Figures 1, 4A–C, 7A–F

Material examined. Holotype. Macquarie Ridge: NIWA 40314 (1) Stn TAN0803/69, 52.39°S 160.65°E, 438–451 m, 09/04/2008.

Paratypes. NIWA 68135 (2) same locality data as holotype.

Other material. Macquarie Ridge: NIWA 40050 (1) Stn TAN0803/53, 51.04°S 162.01°E, 398–489 m, 05/04/2008; NIWA 40326 (2) Stn TAN0803/69, 52.39°S 160.65°E, 438–451 m, 09/04/2008.

Description. Psolus species up to 16 mm long, 6 mm high, 5 mm wide. Body form oval, low profile, body wall thin and soft. Oral and anal openings inconspicuous with no distinctive valves.

Dorsal and lateral scales inconspicuous, glassy bead-like texture, up to 800 µm diameter, decreasing in size towards lateral edge. Sole elongate oval, thin walled, slight anterior taper. Tube feet on sole periphery in 2 rows; inner series close together, continuous, terminal disc up to 400 µm diameter; outer series smaller, terminal disc up to 250 µm diameter, sparsely arranged, not complete. Midventral single row of scattered tube feet, which can be long with terminal discs on ends of extended stalks, some extending over the sole margin.

Dorsal and lateral ossicles single-layered perforated plates (scales), some with secondary thickening and ribbing towards centre of plates, up to 810 µm wide; cups up to 45 µm long, 30 µm deep with a cross-type base, knobbed edges. Ventral ossicles single-layered, smooth perforated plates up to 150 µm long, sparse cups up to 65 µm long. Tentacle ossicles single-layered perforated plates only, up to 230 µm long.

Colour. Preserved: white.

Distribution. Macquarie Ridge, 398– 489 m.

Etymology. Named after the type locality, Macquarie Island.

Remarks. Psolus macquariensis sp. nov. is closest to southern Australian species Psolus steuarti Mackenzie and Whitfield, 2011 , with its similar granulated scales dorsally and laterally, and cups in the dorsal body wall. P. macquariensis sp. nov. differs from P. steuarti in the presence of midventral tube feet and in the dorsal and lateral ossicles consisting of only single-layered plates. Also, in P. macquariensis sp. nov., ventral ossicles are smooth perforated plates, while P. steuarti has knobbed plates.