Satsuma squamigera, Hwang, Chung-Chi & Wu, Shu-Ping, 2018

Hwang, Chung-Chi & Wu, Shu-Ping, 2018, Two new species of Satsuma A. Adams, 1868 from Taiwan (Pulmonata, Camaenidae), ZooKeys 795, pp. 115-126 : 118-119

Satsuma squamigera sp. n. Figures 1, 2, 3

Type material.

Holotype NMNS-7944-001, dry shell and dissected soft part in ethanol, coll. C. C. Hwang, 19 May 2016, collected from type locality; paratype NMNS- 7944-002, 1 specimen: dry shell and dissected soft part in ethanol, coll. S.P. Wu, 24 Jul 2014, collected from type locality; paratypes NMNS-7944-003, 5 specimens: 5 dry shells and 1 dissected soft part in ethanol, coll. S.T. Yang, 11 Feb. 2011, collected from type locality, paratypes NMNS-7944-004, 4 specimens: dry shells, coll. C. C. Hwang, 19 Aug 2014, collected from type locality, paratypes UTM2018001-5, 5 specimens: dry shells, coll. S. P. Wu, 11 May 2012, collected from type locality.

Type locality.

Taiwan: Pingtung County, Shih-tze, Ka-yo-fong waterfall (also named Nei-shih waterfall), 22°17.55'N; 120°41.88'E, alt. 170 m, secondary lowland broad-leafed forest (Figure 1A).

Diagnosis.

Shell sinistral with coarse and irregularly ridged and fine striations; surfaces with dense, fine, erected, triangular scales falling off easily; periphery angulated, umbilicus partly opened; penial caecum short, internally with elongated verge formed by two main pilasters.

Description.

Shell. Measurements (n = 11): SH 12.1-13.9 mm, SW 18.5-20.7 mm, AH 6.9-8.2 mm, AW 11.0-12.2 mm, W# 5.5-5.75, SH/SW 0.61-0.71; sinistral, with low conical spire, light brown to dark brown with red-brown peripheral band and umbilicus spot. Apex obtuse. Whorls regularly increasing, slightly convex. Periphery angulated. Base of shell convex. Surface completely covered with dense, fine, erected, curved, triangular, easily-dislodged scales and leaving crescent-shaped trace; upper surface with coarse, oblique axial ridges; spiral striation absent. Aperture roundly lunate. Peristome expanded; outer lip smoothly curved; columellar lip oblique, curve, joining curved basal lip smoothly or in an angle. Parietal callus smooth, thin, transparent. Umbilicus open, 2.6-3.2 mm in width, 1/5 covered by reflected columellar lip.

External morphology. Light brown with irregular, small, dark brown spots and a distinct yellowish line running from head between tentacles to collar. Tentacles dark brown.

Reproductive system. Bursa copulatrix oval with long pedunculus of 27-30 mm. Free oviduct short. Vagina muscular, furrowed externally corresponding to internal folds, 10-12 mm in length. Atrium short, finely wrinkled inside. Penis slender, 10-12 mm in length, evenly thickened, furrowed externally corresponding to 7-8 strong, straight, corrugated pilasters internally. Penial caecum short, protruding 2-3 mm. Verge extending along penial caecum, formed by two main pilasters, with wrinkled surface. Epiphallus slender, 15-17 mm in length, internally with 4 smooth pilasters. Penis retractor muscle attached at distal 1/4 of epiphallus. Flagellum short, tapering.

Etymology.

From squamigera (Latin, adjective in the nominative feminine singular case) meaning scale-bearing, for the scaly shell surface.

Distribution.

This species was found in southern Pingtung County, including the type locality, Da-han-shan forest road (22°24.20'N; 120°45.31'E, alt-1555 m), Mt. Bei-li-long (22°11.81'N; 120°43.63'E, alt-320 m) and Mu-dang (22°8.43'N; 120°48.34'E, alt-240 m) (Figure 1 A–D).

Ecology.

All specimens were collected in mountainous, lowland, broad-leafed forest. Mature adults were collected in mid-May and February, from ground, rocks or fallen tree trunks. This species is sympatric with the congeners Satsuma bacca (Pfeiffer, 1866), Satsuma batanica pancala (Schmacker & Boettger, 1891) and Satsuma longkiauwensis Wu, Lin & Hwang, 2007.

Remarks.

Satsuma squamigera sp. n. is distinguished from all other sinistral species by having dense and curved scales on the whole shell surface. When fully matured, the scales typically fall off, leaving crescent-shaped granules. Some intact scales may remain beside sutures, on the base of the last whorl or inside the umbilicus. The new species is similar to S. pekanensis (Rolle, 1911) and S. submeridionalis (Zilch, 1951) in shape of shell and angulated periphery. In comparison to S. pekanensis , the new species has a shortened spire and an extended flagellum ( Chang 1989). The new species differs from S. submeridionalis in having a slender base of pedunculus of bursa copulatrix and a regularly thickened proximal vagina ( Wang et al. 2014).