Satsuma vallis, 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 : 478-480

SATSUMA VALLIS SP. NOV. ( FIGS 33 , 34 )

Material examined

Type specimen: Holotype: TMMT 0612 (from type locality, dry shell, tissue in alcohol). Five paratypes: all from type locality, TMMT 0664 (dry shell, tissue in alcohol, dissected); TMMT 0643 (dry shell, tissue in alcohol); BMNH 20060763 , ANSP 413682 , SMF 329390 (dry shell).

Type locality

Gekou, Taroko National Park , Hualien County, eastern Taiwan ( Fig. 1 , Table 1) .

Diagnosis

Shell and soft body yellowish without pedal stripe; pre-apertural constriction present behind outer lip; bursa stalk shorter than spermoviduct; spinule absent; principal pilaster short; proximal penis short, apparently expanded.

Etymology

L. vallis : a valley, after the type locality, ‘Taroko valley’.

Description

Shell ( Fig. 33 ): Dextral, conical, thin, semitranslucent, medium sized to small. Apex obtuse. Whorls expanded. Periphery bluntly angulated. Base expanded. Pre-apertural constriction present only behind outer lip. Shell colour pale yellow with unevenly distributed white stripes. Periostracum thin. Surface even, with fine axial and spiral striae. Aperture diagonal ovate. Junction between outer lip and inferior lip roundly angulated. Peristome thin, expanded at inferior lip and outer lip. Inferior lip curved downward. Columellar lip subvertical, reflected. Umbilicus mostly covered by columellar lip, crevice-like. Junction between columellar lip and inferior lip obtusely angulated.

Band or stain: Polymorphism exists in this taxon. Although some individuals exhibit neither colour banding nor staining, others possess a light brown stain at the umbilicus and the apex. Band formula = 0 0 0 0 0 0 0 0; 1 0 0 0 0 0 7 0 (rare) ( Fig. 2 ).

Reproductive system ( Fig. 34 ): Bursa stalk short, twothirds length of spermoviduct, tapering, not enlarged at base. Bursa copulatrix clavated. Proximal vagina short, swollen, with 16–19 folds; middle vagina very short, not particularly constricted, with 18–20 weak and wiggly folds inside; distal vagina long, nearly half length of vagina, same width as proximal vagina, constricted towards atrium, with low folds or fine wrinkles inside. Flagellum short, conical, swollen at base, with short, suddenly reduced and digitate tip. Epiphallus long, with four pilasters inside. Penial caecum moderate, conical, blunt, weakly furrowed on surface; cecal pilaster two in number; remaining inner walls of penial caecum contain six weak ridges. Proximal penis short, expanded, weakly furrowed externally, with one deep groove corresponding to principal pilaster internally; principal pilaster same length as penial caecum; middle penis constricted suddenly, regularly elongated, smooth externally, with six to eight strong pilasters; distal part short, with only weak folds or fine wrinkles inside. Spinules absent. Two individuals from the type locality were dissected.

Distribution

The species inhabits lowland (<200 m) forest around the Taroko valley , Hualien County, eastern Taiwan. The animals were usually found at the Gekou area

Figures

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

Figure 2. Band formula and colour stain demonstrating polymorphism of banding patterns. Numbers 1–8 show the position of the band. A ‘0’ means no bands or stains present. Digits in parentheses denoted a smear displayed between and connected with the bands or stains. See text for definition of bands and stains in detail.

Figure 33. Satsuma vallis sp. nov. A–D, holotype (TMMT 0612, shell height = 18.5 mm). E, F, paratype (TMMT 0643, shell height = 16 mm). G, living specimen. Arrow indicates the pre-apertural constriction.

Figure 34. Reproductive system of Satsuma vallis sp. nov. (paratype, TMMT 0664). A, whole genitalia; B, interior of genitalia. Scale bar = 5 mm. See text for abbreviations.