Leptoplax richardi ( Kaas, 1990 ) Sirenko & Saito, 2017

Sirenko, Boris I. & Saito, Hiroshi, 2017, New species of chitons of the superfamily Cryptoplacoidea (Mollusca: Polyplacophora) from Vietnamese waters, Zootaxa 4299 (4), pp. 451-506 : 469

Leptoplax richardi ( Kaas, 1990) n. comb.

Fig. 16

Notoplax (Notoplax) richardi Kaas, 1990: 178 –179, figs 1–10. Notoplax richardi: Kaas & Van Belle, 1998: 158 .

“ Notoplax ” sp. cf. richardi: Saito, 1998: 158 –160, fig. 8.

Type material. Holotype, MNHN-IM-2000-6111.

Type locality. Capel Bank, Coral Sea, 25°20´S, 159°44´E, 56 m.

Material examined. Southern Vietnam, Cau Id., 11°13.322´N, 108°49.866´E, 12–13 m, SCUBA, sand, tail valve, 14.05.2013, leg. B. Sirenko.

Distribution. Coral Sea; Southern Vietnam; Goto Islands, Japan, 6– 56 m.

Remarks. The tail valve ( Fig. 16 ) which is the only known specimen of this species collected during the survey of collected sand is identifiable to Notoplax richardi Kaas, 1990 [= Leptoplax richardi ( Kaas, 1990) n. comb.] described from Coral Sea, at the depth of 56 m by the outline of tegmentum, wavy margins of the jugum which has oblique sulci and 2–7 micraesthete pores distributed in the proximal half of the pustule.

The generic assignment of this species is changed from Notoplax to Leptoplax herein, based on the diagnostic features of the sutural laminae of the tail valve and the central part of the radula. The latter is shown in Saito (1998: 159, Fig. 8 A). This is the first record of this species from Vietnamese waters.

Figures

FIGURE 8. Notoplax odysseyi n. sp., Southern Vietnam, Off Phan Rang, holotype, BL 51 mm: A. Needle of tufts; B. Dorsal needles, C. Ventral spicules, D. Head of major lateral tooth of radula; E. Central and first lateral teeth of radula; F. Pustule of lateropleural areas of tegmentum. Scale bars: 100 µm.

FIGURE 16. Leptoplax richardi, Southern Vietnam, Cau Id.: A. Valve VIII, dorsal view; B. Valve VIII, lateral view; C. Valve VIII, detail of tegmentum in antemucronal area.