Amphidromus madelineae Thach, 2020

Jirapatrasilp, Parin, Huang, Chih-Wei, Sutcharit, Chirasak & Lee, Chi-Tse, 2024, The arboreal snail genus Amphidromus Albers, 1850 (Eupulmonata, Camaenidae) of Southeast Asia: 1. Molecular systematics of some Vietnamese species and related species from Cambodia, Indonesia, and Laos, ZooKeys 1196, pp. 15-78 : 15

Amphidromus madelineae Thach, 2020

Figs 22B , 24H-M , 25C, D , 26

Amphidromus madelineae Thach, 2020a: 68-69, pl. 48, figs 592, 593; pl. 49 figs 594-596. Type locality: Quang Nam Province, Central Vietnam. Thach 2021: 68.

Material examined.

Vietnam: Sinistral , holotype of " Amphidromus madelineae ", MNHN-IM-2000-35566 (Fig. 24H ) .

Other material examined.

Vietnam: 5S specimens, Duy Xuyen District, Quang Nam Province, NMNS-8764-108- NMNS-8764-112 (Fig. 24I, J ); 10S specimens, Za Hung, Dong Giang District , Quang Nam Province, NMNS-8764-113- NMNS-8764-122 (Fig. 24K-M ) .

Diagnosis.

Shell small to medium, sinistral; apex tinted pink to purplish pink. Parietal callus transparent; lip whitish to purplish pink; columella and inner side of outer wall around columella purplish pink. Genitalia without appendix.

Differential diagnosis.

Amphidromus madelineae differs from the similar sinistral species A. haematostoma in having tinted-pink colour ~ 1-2 whorls from apex, and thin and transparent parietal callus, while A. haematostoma has a whitish apex, slightly thickened parietal callus with pale to dark rose-pink colour. This species also differs from the similar A. roseolabiatus in that the latter has a chirally dimorphic shell, a whitish apex and the genitalia with a very long appendix. The molecular phylogeny in this study reveals that A. madelineae is a distinct clade from its sister A. haematostoma (Figs 2 , 26 ). The COI and 16S p -distances between A. madelineae and A. haematostoma are 13.93% and 6.04%, respectively (Table 2 ).

Description.

Shell small to medium (height 27.7-38.0 mm, width 16.2-20.2 mm), sinistral, elongate to ovate conical, rather thin and glossy. Spire conical; apex acute, tinted pink to purplish pink and without black spot on tip. Whorls 5-6 nearly smooth; suture wide and shallow; last whorl rounded to nearly globose. Periostracum usually deciduous to yellowish green radial streaks, more conspicuous on last whorl and faded in earlier whorls. Last whorl with thin, dark green subsutural band, sometimes with irregular greenish spiral blotched bands below periphery; varix sometimes present. Parietal callus thin and transparent. Aperture ovate to elongate; peristome little thickened and expanded; lip generally whitish to purplish pink; inner side of outer wall whitish around columella with purplish pink colour. Columella straight, thickened and pale to dark purplish pink. Umbilicus imperforate.

Radula. Teeth arranged in anteriorly pointed V-shaped rows. Central tooth monocuspid and spatulate with truncated cusp. Lateral teeth bicuspid; endocone small, slightly elongate, with wide and deep notch, and dull cusp; ectocone large with slightly blunt to dull cusp. Lateral teeth gradually transformed to asymmetric tricuspid marginal teeth. Outermost teeth with small and multicuspid (Fig. 22B ).

Genital organs. Atrium relatively short. Penis stout, cylindrical, and short, ~ 1/2 as long as vagina. Penial retractor muscle thickened, short and inserting on epiphallus close to penis. Epiphallus stout tube and approximately as long as vagina. Flagellum short, extending from epiphallus and terminating in slightly curved tip; appendix absent. Vas deferens slender tube passing from free oviduct and terminating at epiphallus-flagellum junction (Fig. 25C ). Internal wall of penis corrugated, exhibiting prominent series of thickened and smooth surfaced longitudinal penial pilasters forming fringe around penial wall. Penial verge very short and with smooth surface (Fig. 25D ).

Vagina long cylindrical, and ~ 2 × longer than penis. Gametolytic duct long cylindrical tube then gradually tapering to slender tube terminally and connected to bulbus gametolytic sac. Free oviduct short; oviduct compact, forming lobule alveoli (Fig. 25C ). Internal wall of vagina possessing slightly corrugated ridges near genital orifice; ridges becoming roughly irregular vaginal pilasters in middle and close to free oviduct opening (Fig. 25D ).

Distribution.

This species is found in Quang Nam Province, Vietnam.

Remarks.

Specimens from Za Hung, Dong Giang, Quang Nam, Vietnam (Fig. 24L, M ) are superficially similar to A. haematostoma in having greenish shell colour and a purplish pink lip.

Figures

Figure 2. Bayesian phylogeny of Amphidromus spp. based on mitochondrial COI and 16 S genes. Nodal support values are given as SH-aLRT / aBayes / ultra-fast bootstrap (IQ-TREE, ML) / posterior probability (MrBayes, BI). An asterisk on each branch indicates a clade with all well-supported values (SH-aLRT ≥ 80 %, aBayes ≥ 0.95, BS ≥ 95 %, PP ≥ 0.95). Species numbers correspond to those in Fig. 1 and Tables 1, 2.

Figure 22. SEM images of the radula A Amphidromus metabletus Moellendorff, 1900 from Nha Trang, Khanh Hoa, Vietnam (NMNS- 8764 - 130) B Amphidromus madelineae Thach, 2020 from Duy Xuyen, Quang Nam, Vietnam (NMNS- 8764 - 110) C Amphidromus costifer Smith, 1893 from Ea Sup, Dak Lak, Vietnam (NMNS- 8764 - 048). Central teeth are marked in yellow. The left and right images show the outer and inner sections of each radula, respectively.

Figure 24. Shells of Amphidromus spp A-G Amphidromus haematostoma Moellendorff, 1898 A Lectotype of " Amphidromus haematostoma var. viridis " (SMF 7559) B lectotype of " Amphidromus haematostoma var. varians " (SMF 7561) C holotype of " Amphidromus attapeuensis " (NHMUK 20170278) D specimen from Samphanh, Phongsali, Laos (NMNS- 8764 - 056) E, F specimens from Ba Chien, Pakse, Champasak, Laos (NMNS- 8764 - 064, NMNS- 8764 - 076) G specimen from Kbang, Gia Lai, Vietnam (NMNS- 8764 - 080) H-M Amphidromus madelineae Thach, 2020 H holotype of " Amphidromus madelineae " (MNHN-IM- 2000 - 35566) I, J Specimens from Duy Xuyen, Quang Nam, Vietnam (NMNS- 8764 - 112, NMNS- 8764 - 108) K-M specimens from Za Hung, Dong Giang, Quang Nam, Vietnam (NMNS- 8764 - 114, NMNS- 8764 - 118, NMNS- 8764 - 122).

Figure 25. Genitalia of Amphidromus spp A, B Amphidromus haematostoma Moellendorff, 1898 from Ba Chien, Pakse, Champasak, Laos (NMNS- 8764 - 061), showing A general view of genitalia B interior structures of penis and vagina chamber C, D Amphidromus madelineae Thach, 2020 from Duy Xuyen, Quang Nam, Vietnam (NMNS- 8764 - 110), showing C general view of genitalia D interior structures of penis and vagina chamber. Red dots indicate the shape of the missing gametolytic sac. Green arrows indicate the genital openings. Abbreviations: e, epiphallus; fl, flagellum; fo, free oviduct; gd, gametolytic duct; gs, gametolytic sac; ov, oviduct; p, penis; pp, penial pilaster; pr, penial retractor muscle; pv, penial verge; v, vagina; vd, vas deferens; vp, vaginal pilaster.

Figure 26. Bayesian phylogeny of Amphidromus haematostoma Moellendorff, 1898 and Amphidromus madelineae Thach, 2020 based on mitochondrial COI and 16 S genes. Nodal support values are given as SH-aLRT / aBayes / ultra-fast bootstrap (IQ-TREE, ML) / posterior probability (MrBayes, BI). An asterisk on each branch indicates a clade with all well-supported values (SH-aLRT ≥ 80 %, aBayes ≥ 0.95, BS ≥ 95 %, PP ≥ 0.95).