Leptochiton schwabei Sigwart & Sirenko, 2012

Sirenko, Boris I., 2020, New shelf and bathyal Philippine leptochitons (Mollusca: Polyplacophora Lepidopleurida), Zootaxa 4878 (3), pp. 467-500 : 479

Leptochiton schwabei Sigwart & Sirenko, 2012

( Figs. 14–16 )

Leptochiton schwabei Sigwart & Sirenko 2012: 23 , figs 4G, 17, 18.

Type material. Holotype (MNHN-IM-2000-23703) and 15 paratypes (MNHN-IM-2000-23704) and 1 paratype ( ZISP).

Type locality. Solomon Islands, 8°32.8’S, 160°41.7’E, 399–700 m ;

Material examined. Philippines. PANGLAO 2005, Bohol / Sulu seas, stn CP2385, 8°51’N, 123°10’E, 982–989 m, 3 spms (MNHN-IM-2013-67040), BL 5.0–6.0 mm, 29.05.2005 .

Distribution. Vanuatu (641–900 m), the Solomon Islands (500–839 m) and now the Philippines (982–989 m). Found living and feeding on sunken terrestrial plant remains.

Remarks. The studied specimen (MNHN-IM-2013-67040) conforms well with the type material. It has four gills on each side, and a radula 2.5 mm long with 34 transverse rows of mature teeth. Each granule of the tegmentum of the studied specimen has five pores of aesthetes.

This species differs distinctly from its congeners by having 4 gills, quincuncially arranged granules on the tegmentum and intersegmental areas and marginal chitinous bristles with needle-like spines at their tip.

Figures

FIGURE 14. Leptochiton schwabei, Philippines (MNHN-IM-2013-67040), BL 6.0 mm: A. Valve I, dorsal view; B. Valve II, dorsal view; C. Valve V, dorsal view; D. Valve VIII, dorsal view; E. Valve IV, ventral view; F. Valve V, detail of tegmentum in central and lateral areas; G. Valve VIII, lateral view; H. Valve V, rostral view.

FIGURE 15. Leptochiton schwabei, Philippines (MNHN-IM-2013-67040), BL 6.0 mm: A. Dorsal and ventral scales and marginal needles; B, C. Dorsal scales and needles; D. Sutural scales and needles.

FIGURE 16. Leptochiton schwabei, Philippines (MNHN-IM-2013-67040), BL 6.0 mm: A. Radula; B. Central and first lateral teeth of radula.