Satsuma longkiauwensis, Wu, Shu-Ping, Lin, Yao-Sung & Hwang, Chung-Chi, 2007

Wu, Shu-Ping, Lin, Yao-Sung & Hwang, Chung-Chi, 2007, A new Satsuma species (Pulmonata: Camaenidae) endemic to Taiwan, Zootaxa 1608, pp. 59-68 : 61-65

Satsuma longkiauwensis sp. nov.

( Figs. 2–5 )

Type material. Type locality: TAIWAN: Pingtung County, Shuangliu, 22º13’7.3”N 120º47’35.9”E, alt. 280 m; TMMT 0 701 (holotype): adult with decaying soft body in ethanol, collected by S.-P. Wu, 20 Oct. 2005; TMMT 0 705 (paratype): adult dissected for genitalia, radula and jaw, remaining soft parts in ethanol, collected by S.-P. Wu, 13 Sept. 2005; TMMT 0 704 (paratype): sub-adult dissected for radula and jaw, remaining soft parts in ethanol, collected by S.-P. Wu, 13 Sept. 2005; TMMT 0 706 (paratype): sub-adult soft body in ethanol, collected by S.-P. Wu, 13 Sept. 2005; TMMT 0 707 (paratype): adult shell, collected by S.-P. Wu, 21 Feb. 2004; BMNH 20060795 and ANSP 413696 (paratypes): adult shell, collected by S.-P. Wu, 20 Oct. 2005. Other locality: TAIWAN: Pingtung County, Mudan, 22º07’55.4”N 120º47’18.5”E, alt. 225 m; empty adult shells: NMNS 5415-001–003 (three paratypes) and TMMT 0702–0703 (two paratypes): collected by C.-C. Hwang, 26–27 Aug. 1997.

Diagnosis. A large-sized, dextral Satsuma with light brown to olive background with depressed base and open umbilicus; Reproductive system with robust flagellum, swollen distal vagina, truncated oval verge, thick and muscular sheath tying male genitalia and expansive base of spermathecal stalk.

Etymology. Longkiauw (Langjiao) is the ancient name of nowadays Hengchun Peninsula and originates from the aboriginal race Paiwan.

Description. Shell ( Fig. 2 ): large, dextral, semi-spherical, thick, rigid; height 24–33 mm; width 34–41 mm; 5 7/8 –6 1/8 whorls. Apex obtuse. Whorls strongly inflated. Periphery bluntly angulated. Base of shell bulged outwards and flattened behind peristome; Surface of periostracum smooth, glossy, with faint oblique and spiral striations. Color of shell light brown to olive with red-brown stain. Peripheral band thin, sharp, redbrown. Surface above peripheral band brown, gradually lighter towards suture; area immediately below peripheral band yellowish white; basal band light brown colored, broad, gradually smear towards umbilicus. Umbilicus uncolored. Aperture diagonal, ovate. Peristome in lateral view concave. Lip thick, expanded; reflected at outer and inferior parts. Columellar lip oblique, straight; dilation of columellar lip not covering umbilicus. Lip color dark purple-red, glossy. Parietal callus thin, semitransparent. Umbilicus open, broad, deep. Holotype: height 28 mm, width 39 mm, 6 1/8 whorls ( Fig. 2 A–D).

Reproductive system ( Fig. 3 ): Spermathecal stalk as long as spermoviduct, swollen at basal half, slender till spermatheca, with a constriction dividing base into two expansions of equal length; basal expansion bacillary, with ten to twelve strong, corrugated folds along inside; distal expansion shuttle-shaped, with seven thin, strong zigzag folds inside. Spermatheca oval. Free oviduct long, about same length as basal expansion of spermathecal stalk. Proximal vagina muscular, smooth externally, gross, weaker than basal expansion of spermathecal stalk. Internal folds in proximal vagina continued with those of spermathecal stalk counting nine in number, strongly elevated, lamellate, smooth, gradually weakened towards atrium. Subsequent part of vagina gradually slender towards a sudden swell distally, with ten thin, wiggly folds inside. Distal 1/5 of vagina abruptly thickened, muscular, depressed, pale brown in color, with wide, flattened folds inside. Male genitalia twisted, wrapped by a thin, semi-translucent, muscular sheath. Flagellum moderate, robust, tapering, with thickened base. Epiphallus as strong as base of flagellum with four to six unequally strong pilasters along inside, terminated with a shortly projecting, truncated oval, finely wrinkled verge entering penis. Penial caecum (appendix) not definite, with only an angled expansion surrounding verge. Pilasters around verge weak, wiggly, numbered 15–19. Proximal part of penis strong, thickened with 13 smooth, well-defined, strong pilasters. Subsequent part of penis slender with nine low, wiggly, corrugated pilasters inside. Distal part of penis extended again, about same length as distal swell of vagina, with weak, zigzag, corrugated pilasters internally. Atrium short, finely wrinkled inside.

Radula and jaw: Radula ribbon length 7.6 mm, width 2.6 mm. Radula formula 56 + C + 56. Central tooth with blunt, wide, curved mesocone and two weak, symmetrical ectocones (Fig. 4A). Lateral teeth with narrower, outwardly directed mesocone and weak endocone and ectocone (Fig. 4B). Marginal teeth with more outwardly directed mesocone and prominently forked, pointed endocone and ectocone (Fig. 4C). Jaw dark brown, curved with high, wide vertical ribs, reduced on margins ( Fig. 5 ).

FIGURE 4. Radula of Satsuma longkiauwensis sp. nov. (paratype, TMMT 0705). A. Central tooth; B. Lateral tooth (15th, left); C. Marginal tooth (45th, left). Scale bar = 20 µm.

Distribution ( Fig. 1 ): All specimens were collected in mountainous lowland between the river basin of the rivers Fengangxi and Sichungxi. Living individuals were collected only in Shouangliu, the type locality. Ecology: Live specimens were observed active in the field in September. They were nocturnal and herbivorous feeding on decaying fallen leaves and gramineous shoots ( Fig. 2 E). They were found on ground and crawling on rocks or lower tree trunks.

Remarks: The reproductive system of Satsuma longkiauwensis sp. nov. differs from that of the largesized Satsuma species from Taiwan and Japan, e.g. S. bairdi ( H. Adams, 1866) , S. arisana ( Kuroda, 1941) ssp., S. nux ( Moellendorff, 1888) , S. sphaeroconus ( Pfeiffer, 1866) and S. mercatoria ( Pfeiffer, 1845) , in having a weak expansion instead of an elongated penial caecum externally and a hemispherical verge instead of elongated and thickened pilasters internally ( Minato 1975; Wu & Chang 1975; Azuma & Azuma 1987; Chang 1994, 1997). The reproductive system of the new species is similar to that of S. succincta ( H. Adams, 1866) , Pancala bacca ( Pfeiffer, 1866) and P. batanica pancala ( Schmacker & Boettger, 1891) ( Tabe 1937; Sinagawa 1979; Chang 1992; Hwang 1995), but differs from P. bacca and P. batanica pancala in having a larger shell, roundly angulated peripheries adjacent to the peristome, an angled and less swollen junction between epiphallus and penis, robust and non-twisted flagellum, a more dilated penis at the proximal part and a swollen distal vagina.

Shell morphology of the new species differs from other camaenid species distributed in Hengchun Peninsula, as P. bacca, P. batanica pancala, S. pekanensis ( Rolle, 1911) and S. contraria ( Pilsbry & Hirase, 1909) , in having a larger and/or dextral shell ( Hsieh et al. 2006).

Satsuma arisana tani ( Kuroda, 1941) , which is distributed in southeastern Taiwan, is also similar to the new species in shell dimensions (holotype: height 30.0 mm, width 41.0 mm) and shape. Unfortunately the type specimens were not traceable currently. However, it can be deduced from the original description and photographs of the holotype ( Kuroda 1941) that the umbilicus of S. arisana tani is perfectly covered by the reflected superior columellar lip and completely closed.

Among camaenid species from Taiwan, Satsuma succincta shows a high similarity in shell morphology and banding patterns. Nevertheless, this species is smaller (shell height 16.2–22.8 mm, shell width 23.0– 31.2 mm, 6 syntypes, BMNH 1866.5.9.9) in shell dimensions than the new species. Both species are ground-living in the low land forests of south Taiwan, but not sympatric. The smoothly rounded junction between the outer and inferior lips, yellowish coloration of shell, the robust and smoothly curved flagellum, and the swollen distal vagina of S. longkiauwensis sp. nov. distinguish it further from S. succincta . Satsuma succinct and its allies show an angulated junction at peristome, reddish coloration of shell mostly, slender and wiggly flagellum and slender distal vagina ( Chang 1989; Hwang 1995).

All the 26 valid (sub-)species of Camaenidae from Taiwan can be separated using the key below. This identification key is based on shell characters of type specimens examined except for Satsuma arisana takahasii ( Kuroda, 1941) , S. arisana tani ( Kuroda, 1941) , S. nux paiwanis ( Kuroda, 1941) and S. nux sericata ( Kuroda, 1941) . The type material of these four taxa could not be located. Anatomical characters are not used, as those are not available for all taxa.

Figures

FIGURE 1. Map of Taiwan showing the distribution of Satsuma longkiauwensis sp. nov. Solid asterisk, type locality; empty asterisk, locality of paratypes NMNS 5415 - 001 – 003 and TMMT 0702 – 0703; grey area around asterisks, distribution of Satsuma longkiauwensis; bold black line, Central Range; thin line, administrative boundary.

FIGURE 2. Satsuma longkiauwensis sp. nov. A – D. shell of holotype (TMMT 0701). Scale bar = 10 mm. A. Apertural view; B. Lateral view; C. Basal view; D. Top view; E. Living specimen (paratype TMMT 0704). Photograph by Chung- Yi Hsiao.

FIGURE 3. Reproductive system of Satsuma longkiauwensis sp. nov. (paratype TMMT 0705) A. Whole genitalia, vas deferens is cut to unfold the genitalia; B. Verge and penial caecum; C. Interior of genitalia. Scale bar for A and C = 10 mm, scale bar for B = 1 mm.

FIGURE 5. Jaw of Satsuma longkiauwensis sp. nov. (paratype, TMMT 0705). Scale bar = 600 µm.