Lepidozona christiaensi Van Belle, 1982

Sirenko, B. I., 2016, New and rare species of the genus Lepidozona (Mollusca: Polyplacophora) from the South China, East China and the Philippine seas, The Bulletin of the Russian Far East Malacological Society 20, pp. 28-46 : 30-31

Lepidozona christiaensi Van Belle, 1982

Figs. 1–3

Lepidozona (Lepidozona) christiaensi Van Belle, 1982: p. 471 , figs. 1/1–16; Kaas, Van Belle, 1987, p. 251, fig. 113, map 35.

T y p e m a t e r i a l. The Natural History Museum,London, UK (formerly, BMNH), NHMUK 198244.

T y p e l o c a l i t y. China, Hong Kong, outside Tolo Channel.

M a t e r i a l e x a m i n e d. South China Sea : Vietnam, near Danang, 16 ° 11.802 ′ N, 108 ° 10.593 ′ E, sample 37, SCUBA, 5–12m, on Pinna sp. , 1 spm.,BL 10 mm, 16.05.2012, leg. O. Savinkin ; Hon Cau Island , 11 ° 13.322 ′ N, 108 ° 49.866 ′ E, sample 152, SCUBA, 12–13 m, in sand, 1 intermediate valve, 14.05.2013, leg. B. Sirenko ; sample 227, SCUBA, 7 m, in sand, tail valve, 07.05.2014, leg. S. Grebelniy.

D i s t r i b u t i o n. This material represents the first records of the species in Vietnam which enlarges its range from Hong Kong (22 ° 22 ′ N) south to Hon Cau Island (11 ° 13 ′ N), depth 7–12 m.

R e m a r k s. The whole specimen collected near Danang has 14 gills arranged from valve IV to valve VII, slit formula 13/1/13, radula 2.1 mm long with 30 transverse rows of mature teeth. The gut content containing detritus and foraminifers. The studied specimen has more various marginal spicules than in type specimen [ Van Belle, 1982]. Marginal fringe composed of different flattened spicules, grooved in two directions (feather-like) (40–67x20–24 μm), wedge shaped, obliquely grooved spicules (56x20 μm), and small, numerous, blunt-topped spicules (48x12 μm) with six longitudinal ribs on upper half. All marginal spicules embedded in a short chitinous sheath .

The species is well distinguished from other species of the genus Lepidozona by sculpture of tegmentum with keel in the jugal area and tridentate blade of major lateral tooth of radula.

Figures

Fig. 1. Lepidozona christiaensi, BL 10 mm, Vietnam, 5–12 m, on Pinna sp; A – valve I, dorsal view; B – valve V, dorsal view, C – valve VIII, dorsal view; D – valve V, rostral view; E – valve V, detail of tegmentum in central area; F – valve VIII, lateral view; G – valve IV, ventral view.

Fig. 2. Lepidozona christiaensi, BL 10 mm, Vietnam, 5–12 m, on Pinna sp; A – valve V, detail of tegmentum injugal area; B – dorsal scales; C – dorsal scales, marginal spicules and ventral scales; D – radula.

Fig. 3. Lepidozona christiaensi, BL 10 mm, Vietnam, 5–12 m, on Pinna sp; A – dorsal scale, B– F – marginal scales and spicules; G – ventral scale; H – central and first lateral tooth of radula; I – head of major lateral teeth of radula. Scale bar 100 µm.