Waldeckia nudum (Imbach, 1967)

(Fig. 25 b)

Lepidepecreum nudum Imbach, 1967: 53, pl. 1. ― Barnard & Karaman, 1991: 496. Waldeckia elephas Hirayama & Kikuchi, 1980: 151, figs 1–5. ― Hirayama, 1985: 192. ― Barnard & Karaman, 1991: 542. Waldeckia nudum . ― Lowry, 2000: 322.

? Waldeckia australiensis . ― Ren, 2012: 174, fig. 76.

Types. Holotype, male, 10 mm, ZMUC CRU-7569.

Type locality. Off Nhatrang, Vietnam (12°16.91'N, 109°16.88'E), 18/03/1960, 17 m, coarse brown sand (NAGA Stn 256).

Material examined. 20 specimens, AM P.92567 and 20 specimens, RMBR, SS- 3498 (SW-137) between St Johns and Lazarus Islands, Singapore, baited trap, 25 m depth, N. Bruce & J.K. Lowry, 31 May 2013. 3 specimens, AM P.92568, north-west of Koh Phayam, Andaman Sea (approximately 09°47'49.3"N 98°22'52.3"E) coll. Montri Sumontha, 15 August 2013.

Diagnostic description. Head lateral cephalic lobe large, broad, subacute. Antenna 1 peduncular article 1 without anterodistal projection. Labrum, epistome and upper lip fused. Mandible palp article 2 anterodistal margin setose; article 3 with marginal and apical setae. Labium, apical stylets not known. Gnathopod 1 parachelate; basis with slender setae; propodus posterior margin smooth. Gnathopod 2 minutely chelate; carpus long; palm minute, obtuse; dactylus fitting palm. Pereopod 6 basis posteroventral margin rounded. Pereopod 7 basis, slightly rounded, minutely crenate, posteroventral margin oblique. Epimeron 3 posteroventral corner narrowly rounded. Urosomites 1–3 dorsally smooth. Uropod 1 rami subequal in length; uropod 2 rami subequal in length; uropod 3 rami subequal in length, inner ramus reaching article 2 of outer ramus.

Depth range. 17– 25 m.

Remarks. Imbach (1967) originally described W. nudum in the genus Lepidepecreum . When Hirayama & Kikuchi (1980) described W. elephas they did not consider W. nudum . We think that the type of W. nudum is not fully mature (the mandibular palp is weakly setose in comparison to the type of W. elephas), and is a senior synonym of W. elephas . Waldeckia nudum differs from other species in the genus in the smooth posterior margin of the gnathopod 1 propodus in combination with the minutely chelate gnathopod 2 and the oblique posteroventral margin of the basis of pereopod 7.

Distribution. Japan: Tomioka Bay. Vietnam: Nhatrang. Singapore: Singapore Straits. Thailand: Koh Phang, Andaman Sea.