Leptochiton foresti ( Leloup, 1981 )

Sirenko, Boris I., 2020, New shelf and bathyal Philippine leptochitons (Mollusca: Polyplacophora Lepidopleurida), Zootaxa 4878 (3), pp. 467-500 : 469-471

Leptochiton foresti ( Leloup, 1981)

( Figs. 1–3 )

Lepidopleura [sic] foresti Leloup 1981: 321 , text fig. 2, pl. 2, figs 7–10.

Leptochiton foresti ; Kaas 1982: 88; Kaas & Van Belle 1985: 122–124, fig. 54; Kaas 1990: 176; Sigwart & Sirenko, 2012: 11 . Type material. Holotype (MNHN-IM-2000-5878) and 4 paratypes (MNHN-IM-2000-5945-5946 and MNHN-IM- 2000-5950-5951).

Type locality. Philippines: Verde Island Passage , 25, 14°02.7’N 120°20.3’E, 191–200 m.

Material examined. Holotype and paratypes; Philippines. PANGLAO 2005, Bohol Sea, Balicasag Id. stn CP2392, 9°29.0’N, 123°41.1´E, 242–400 m, 1 spm (MNHN-IM-2000-35000), BL 5.0 mm, 30.05.2005; PANGLAO 2004, stn P1, 9°36’N, 123°45’E, 90–200 m, 1 spm ( MNHN IM-2013-67053 ), BL 11.0 mm, May-July 2004 .

Distribution. Philippines, 137–1764 m.

Remarks. One of the studied specimens (MNHN-IM-2007-35000) possesses ten gills on each side and a radula 2.4 mm long with 29 transverse rows of mature teeth. Each granule of the tegmentum in this specimen has seven pores of aesthetes. The armature of the girdle of this specimen is slightly different from that of Leloup (1981) and of Kaas & Van Belle (1985). In the specimen from the Bohol Sea the girdle is dorsally covered not only by flattened dorsal spicules (up to 80 µm) with 5–6 riblets in its upper half but also by scattered smooth needles (up to 160 µm long); ventral scales with sharp top.

Figures

FIGURE 1. Leptochiton foresti, Philippines (MNHN-IM-2007-35000), BL 5.0 mm:A. Valve I, dorsal view; B. Valve II, dorsal view; C. Valve V, dorsal view; D. Valve VIII, dorsal view; E. Valve V, detail of tegmentum in central area; F. Valve V, rostral view; G. Valve VIII, lateral view; H. valve IV, ventral view.

FIGURE 2. Leptochiton foresti, Philippines (MNHN-IM-2007-35000), BL 5.0 mm: A. Dorsal and ventral scales and marginal needles; B. Dorsal scales and needle; C. Dorsal scales near suture; D. ventral scales.

FIGURE 3. Leptochiton foresti, Philippines (MNHN-IM-2007-35000), BL 5.0 mm: A. Radula; B. Central and first lateral teeth of radula.