Satsuma polymorpha, Wu & Hwang & Lin, 2008

Wu, Shu-Ping, Hwang, Chung-Chi & Lin, Yao-Sung, 2008, Systematic revision of the arboreal snail Satsuma albida species complex (Mollusca: Camaenidae) with descriptions of 14 new species from Taiwan, Zoological Journal of the Linnean Society 154 (3), pp. 437-493 : 460-465

SATSUMA POLYMORPHA SP. NOV. ( FIGS 17–20 )

Material examined

Type specimen: Holotype: TMMT 0606 (from type locality, dry shell, tissue in alcohol). Thirty-four paratypes: 27 paratypes from type locality: TMMT 0680 (dry shell, tissue in alcohol, dissected); TMMT 0627–0630 , TMMT 0632 , TMMT 0673–0674 (dry shell, tissue in alcohol); NMNS 005405-7 – 005405-11 , BMNH 20060776–20060781 , ANSP 413689 , ANSP 413690 (N = 2), ANSP 413691 (N = 2), ANSP 413692 , SMF 329397–329398 (dry shell); two paratypes from Mataian, Hualien: TMMT 0631 , TMMT 0671 (dry shell, tissue in alcohol); one paratype from Ruisui, Hualien: TMMT 0633 (dry shell, tissue in alcohol); two paratypes from Fushan , Yilan: TMMT 0625 (dry shell, tissue in alcohol), BMNH 20060775 (dry shell); one paratype from Youluo , Hsinchu: TMMT 0626 (dry shell, tissue in alcohol); one paratype from Shenmihu , Yilan: TMMT 0672 (dry shell, tissue in alcohol, dissected).

Type locality

Beinan, Taitung County, eastern Taiwan ( Fig. 1 , Table 1) .

Diagnosis

Shell and soft body white with grey pedal stripe; shell height/diameter ratio close to 1.0; number of whorls few, five in most individuals; proximal penis and principal pilaster distinctly short, weak, almost vanishing, absent in individuals from Shenmihu; internal spinules absent in most individuals, present only in a specimen from Shenmihu.

Etymology

Gr. polus: much; Gr. morph: shape, referring to the high polymorphism of banding patterns.

Description

Shell ( Figs 17 , 18 ): Dextral, conical, thin, medium sized. Apex obtuse. Whorls inflated. Periphery bluntly angulated. Base expanded. Pre-apertural constriction behind outer and inferior lips present. Surface even, glossy, with faint spiral striae. Shell colour milky white. Periostracum fine, with polymorphic banding patterns in most individuals. Aperture diagonal, ovate-lunate to rectangular. Peristome thin, inflated, reflected at inferior lip. Superior columellar lip slanted, reflected covering most of umbilicus. Junction between oblique columellar lip and inferior lip angulated.

Band or stain: The taxon demonstrates the highest polymorphism of its group. The banding patterns and stains are varied among individuals. Band formula = 0 0 0 0 0 0 0 0; 0 (0 0) 0 (0) 0 0 0; 0 0 0 0 0 0 7 0; 1 0 0 0 0 0 7 0; 1 0 0 0 0 0 7 8; 1 0 0 0 5 0 7 8; 1 0 (0 4) 5 0 7 8; 1 0 0 4 0 0 7 0; 1 0 0 4 0 0 7 8; 1 0 3 0 5 0 7 8; 1 0 3 0 5 6 0 0; 1 0 3 0 5 0 7 8.

Reproductive system ( Figs 19 , 20 ): Bursa stalk long, slender, with expanded base. Proximal vagina barely widened, furrowed externally, with 11–15 strong, wiggly folds internally; middle vagina varied in length, not as distinguishable as proximal vagina, usually muscular sometimes with thick walls, constrictive, with ten weak, dense folds inside; distal vagina long, two-fifths to three-fifths length of vagina. Flagellum long, tapering, not swollen at base. Pilaster in epiphallus three in number, wide, low. Penial caecum long, robust, tapering, with blunt tip; cecal pilaster two in number, weakly to strongly prominent. Principal pilaster short, almost vanishing. Proximal penis short, muscular, twisted, unevenly furrowed externally, with principal pilaster and eight to ten strong, corrugated pilasters; middle and distal penis short, constrictive near atrium, with gradually vanishing pilasters inside. Spinules observed only in a dissected individual from Shenmihu, Yilan ( TMMT 0672, Fig. 20 ). Five individuals from the type locality, Beinan ( Fig. 19 ), two from Fushan, two from Shenmihu and one immature specimen from Ruisui were dissected. The samples from Shenmihu are different in having (1) an indistinct middle vagina where only a short constriction was seen, (2) weak pilasters in the penial caecum, (3) spinules and in lacking (4) a proximal penis and principal pilaster ( Fig. 20 ).

Distribution

This is the most widespread taxon of its group, distributed in mid-altitude (800–1600 m) forest in east Taiwan (from Shenmihu, Yilan County, to Taimali, Taitung County) and in north Taiwan of lower altitude (from Dananshi , Miaoli County, to Fushan , Yilan County) ( Fig. 1 , Table 1) .

Remarks

Perches 5 m above the ground; at times animals are active in the tree canopy. Adults were found in summer. Brood is frequently 20 ( Fig. 18C–I ).

The shells of northern populations (Miaoli, Hsinchu, Taoyuan, Taipei and north Yilan County) are solely white. Regardless of anatomical characters, they share a common genetic structure with the polymorphic populations distributed in eastern Taiwan (data not shown) .

The species has a similar shell height/diameter ratio to S. hagiomontis sp. nov., but the shell dimensions are smaller than that of the latter species. Most specimens of this species have a smaller shell and lower number of whorls than other white-shelled species in west Taiwan.

SATSUMA MOLLICULA ( PILSBRY & HIRASE, 1909)

( FIGS 21 , 22 )

Ganesella albida mollicula Pilsbry & Hirase, 1909 [1908]: 593–594 (3 March 1909)

Ganesella albida mollicula, Kuroda, 1941: 145 , no. 1062; Sinagawa, 1980: 6–8, figs 4, 5.

Coniglobus (Luchuhadra) albida mollicula, Chang, 1984: 15 .

Satsuma albida mollicula, Richardson, 1985: 268 ; Hsieh et al., 2006: 232.

Luchuhadra albida, Chang, 1985: 7 . [wrong identification]

Satsuma albidum molliculum, Lai, 1990: 49 . [incorrect gender ending]

Material examined

Type specimen: Holotype: ANSP 95753 (dry shell), fixed by monotypy ( Baker, 1963).

Additional material: Specimens were collected from Nanrenshan, eastern Hengchun peninsula, Pingtung County, southern Taiwan. Four specimens were deposited as vouchers: TMMT P- 0282 (dry shell, tissue in alcohol, dissected); TMMT P- 0281 (dry shell, tissue in alcohol); BMNH 20060784, ANSP 413695 (dry shell).

Type locality

Toshun, South Cape of Formosa (south-east of Hengchun Peninsula, Pingtung County, southern Taiwan at present) .

Diagnosis

Shell colour honey yellowish to greenish gold; soft body yellowish without pedal stripe; periphery keeled; number of whorls more than six; base of bursa stalk conic; bursa stalk shorter than spermoviduct; principal pilaster long.

Etymology

L. mollis: soft; - cula: diminutive suffix.

Description

Shell ( Fig. 21 ): Dextral, conical, thin, fragile, semitranslucent, medium sized. Apex obtuse. Whorls inflated. Periphery angulated with keel. Base

Figures

Figure 1. Sampling localities of all taxa in Taiwan. Bold line, Central Range; thin line, administrative boundary.

Figure 17. Satsuma polymorpha sp. nov. A–D, holotype (TMMT 0606, shell height = 14.2 mm). E, F, paratype (TMMT 0625, shell height = 16.7 mm). G, H, paratype (TMMT 0626, shell height = 16 mm). I, J, paratype (TMMT 0627, shell height = 14.6 mm). K, L, paratype (TMMT 0628, shell height = 14 mm). M, N, paratype (TMMT 0629, shell height = 14.5 mm). O, P, paratype (TMMT 0630, shell height = 15.1 mm). Q, R, paratype (TMMT 0631, shell height = 13.8 mm). S, T, paratype (TMMT 0632, shell height = 14.9 mm). Arrow indicates the pre-apertural constriction.

Figure 18. Satsuma polymorpha sp. nov. A, B, paratype (TMMT 0633, shell height = 17.1 mm). C–I, living specimens.

Figure 19. Reproductive system of Satsuma polymorpha sp. nov. from Beinan, Taitung (paratype, TMMT 0680). A, whole genitalia; B, interior of genitalia. Scale bar = 5 mm. See text for abbreviations.

Figure 20. Reproductive system of Satsuma polymorpha sp. nov. from Shenmihu, Yilan (paratype, TMMT 0672). A, whole genitalia; B, interior of genitalia. Scale bar = 5 mm. See text for abbreviations.

Figure 21. Satsuma mollicula. A–D, holotype (ANSP 95753, shell height = 21.2 mm). E, living specimen.

Figure 22. Reproductive system of S. mollicula (TMMT P-0282). A, whole genitalia; B, interior of genitalia. Scale bar = 5 mm. C, spinules (scale bar = 0.5 mm). See text for abbreviations.