Satsuma sunlinksea, Hwang & Wu, 2024

Hwang, Chung-Chi & Wu, Shu-Ping, 2024, Three new species of Satsuma Adams, 1868 (Gastropoda, Camaenidae) from Taiwan, Zoosystema 46 (3), pp. 61-76 : 70-73

Satsuma sunlinksea n. sp.

杉"溪栗ª

( Fig. 6 )

urn:lsid:zoobank.org:act:C33584AB-0830-4929-84DC-27A1204300BD

Satsuma sp. 7 – Hoso et al. 2010: suppl. fig. S1, suppl. data 2.

TYPE MATERIAL. — Holotype. Taiwan • Nantou County, Lugu Township, Longfongsia ; 23°39’17”N, 120°46’53”E; alt. 1700 m a.s.l.; 28.IX.2019; S. P. Wu leg.; NMNS-8676-010 ; SH 27.0 mm, SW 32.9 mm.

Paratypes. Taiwan • 2 specimens; from type locality; 22.VII.2022; S. P.Wu leg.; NMNS-8676-011 , MNHN-IM-2022-13917 • 1 specimen; from type locality; 1.VIII.2010; S. P. Wu leg.; NMNS-8676- 012 • 2 specimens; from type locality; 28.VII.2011; S. P. Wu leg.; NMNS-8676-013 , UTM-2023003 • 6 specimens; from type locality; 3.IX.2019; S. P. Wu leg.; NMNS-8676-014 • 1 specimen; Nantou County, Lugu Township, Sunlinksea, Songlongyen ; 23°37’12”N, 120°48’6”E; alt. 1720 m a.s.l.; 24.IV.2019; S. P. Wu leg; NMNS-8676-015 .

ETYMOLOGY. — The species is named for its type locality, where is close to the Sunlinksea Vacation Resorts; treated as a simple noun in apposition.

TYPE LOCALITY. — Taiwan, Nantou County, Lugu Township, Longfongsia ; 23°39’17”N, 120°46’53”E; alt. 1700 m a.s.l.

DISTRIBUTION. — This species was found in type locality and Sunlinksea, 4 km apart.

DIAGNOSIS. — Shell dextral, conical, medium sized (SW <35 mm); spiral striation, fine above periphery, weakly malleated immediately below periphery; periphery roundly angulated; upper lip weakly sinuated; columellar lip oblique, almost straight; basal lip straight and slightly downward; umbilicus partly open; penis with a muscular expansion distally, penial pouch absent; penial caecum conical and short; epiphallus swollen basally.

DESCRIPTION

Shell dextral, with conical spire, brown to dark brown with red-brown peripheral band and umbilicus spot; thin and yellowish area visible immediately below suture and peripheral band. Apex acute. Whorls regularly increasing, slightly convex, not descending behind aperture. Periphery almost round, very weakly angulated. Base of shell convex. Surface covered with small, dense, elongate, axial granules on apical four whorls, becoming loose, coarse, continuous, oblique axial ridges that are weak on base ( Fig. 7C ); spiral striation fine above periphery, weakly malleated immediately below periphery, clear and loose on base of shell. Aperture roundly lunate, light purplish inside. Peristome expanded; upper lip weakly sinuated; columellar lip oblique, almost straight, joining straight and slightly downward basal lip in an angle. Parietal callus thin. Umbilicus partly open, c. 1/2 covered by reflected columellar lip.

Measurements

SH 23.0- 27.9 mm, SW 26.4-36.3 mm, AH 12.1-16.1 mm, AW 16.8-21.8 mm, W# 5.75-6.5, protoconch 2.5 whorls, SH/SW 0.800 -0.894 (n = 13).

External morphology

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

Reproductive system

Bursa copulatrix elongated oval. Pedunculus of bursa copulatrix as long as spermoviduct, 30.7-32.4 mm, thickened and expanded basally, gradually slender toward bursa copulatrix. Free oviduct short, 3.5-5.3 mm. Vagina 24.9-29.1 mm, thick, becoming slender towards atrium, smooth externally, with 9-11 thin internal pilasters. Atrium short, coarsely wrinkled inside. Penis elongated, 35.4-41.7 mm in length, 1.4 times as long as vagina; slender basally, continued with an expanded portion having 6-8 smooth and muscular internal pilasters, penial pouch absent; thickened near epiphallus, twice the thickness of basal portion, smooth externally, with strong, corrugated longitudinal pilasters internally, numbered 7 at distal portion, gradually becoming 23 around penial verge. Penial caecum conical, short, 1.7-2.4 mm. Verge low conical, elongated, formed by six pilasters, extending along penial caecum. Epiphallus slender, 11.3-14.0 mm in length, internally with 3 major and 2 minor pilasters along the entire length. Penis retractor muscle attached at basal 1/3-1/5 of epiphallus. Flagellum 7.1-7.5 mm; swollen basally, internally with thick swelling extending from epiphallic pilasters, opening into vas deferense at base; tapering toward tip, internally with 3-4 pilasters.

REMARKS

Satsuma sunlinksea n. sp. is similar to S. nivnu n. sp. and S. nux ( Fig. 4A ) in the shape of the shell. Satsuma nivnu n. sp. differs from S. sunlinksea n. sp. in having a larger shell, greater number of whorls, smoothly curved outer and basal lips, malleated upper surface above periphery, distinct penial pouch, and shorter penis relative to shell height. Satsuma nux differs from the new species in having a malleated surface above the periphery, latticed shell base, less covered umbilicus (1/3), a horizontal basal lip, and smaller shell sizes (23.6 × 29.0 mm, lectotype SMF 8826, photographed in Zilch 1966, plate 5, fig. 24). The genitalia of S. nux ( Fig. 4 B-E) shows a shorter penial caecum, fewer penial pilasters (7-11), more epiphallic pilasters (4-6), and a stronger protrusion on the radix of the flagellum than S. sunlinksea n. sp. The gene sequences of these species have been examined for the evolution of chirality ( Hoso et al. 2010: supplementary fig. S1, Satsuma sp. 7 ). The phylogenetic tree shows its sister species is an undescribed species ( Hoso et al. 2010: supplementary fig. S1, Satsuma sp. 3 ) collected from Tengchih, a mountainous area in Kaohsiung City, rather than S. nux .

Figures

FIG. 6. — Shell and reproductive system of Satsuma sunlinksea n. sp.: A, shell of holotype (NMNS-8676-010); B, C, genitalia (paratype NMNS-8676-012): whole genitalia (B), opened genitalia (C). Scale bars 10 mm. Abbreviations: see Material and methods.

FIG. 7. — Shell sculptures on the 3rd whorl (A, B, C); surface of the last whorl (D, E, F); shell base (G, H, I): A, D, G, Satsuma hsuehshan n. sp.; B, E, H, Satsuma nivnu n. sp.; C, F, I, Satsuma sunlinksea n. sp. Scale bars: A-C, 0.5 mm; D-I, 1 mm.

FIG. 4. — Shell and reproductive system of Satsuma nux (MÖllendorff, 1888): A, shell (HCC-1925); B, whole genitalia (HCC-14121a); C, male genitalia showing penial caecum (HCC-1925); D, opened genitalia (HCC-14121a); E, opened male genitalia showing verge (red outlined, HCC-1925). Scale bars: 10 mm, unless otherwise noted. Abbreviations: see Material and methods.