Amphidromus bozhii Wang, 2019

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 bozhii Wang, 2019

Figs 4C , 8D-F , 9A-C , 10

Amphidromus bozhii Wang, 2019: 300-301, pl. 3, figs a, b. Type locality: Phu Yen Province, Vietnam.

Material examined.

Vietnam: 10D specimens, Phu Hoa District, Phu Yen Province, NMNS-8764-004- NMNS-8764-013 (Fig. 8D, E ); 8S specimens, Tuy Hoa District , Phu Yen Province, NMNS-8764-014- NMNS-8764-021 (Fig. 8F ) .

Diagnosis.

Shell large conical and chirally dimorphic. Shell surface with coarse growth lines; last whorl nearly absent of spiral depression area and keel. Genitalia with appendix.

Differential diagnosis.

This species is similar to A. ingens in most of the shell form and sculpture. The distinguishing characters are the shell colour which is generally rose-pink to dark colour. The last whorl is stained with dark brown colour below periphery and ~ 1/2 of upper periphery. The shell sculpture has a very weak spiral depression area and sometimes with or without keel. This species looks like an intermediate form between A. ingens and A. placostylus . Amphidromus bozhii is also recognised by a distinct clade in the molecular phylogeny (Fig. 2 ), with the closest p -distance to A. placostylus in COI (9.61%) and A. ingens in 16S (2.76%) (Table 2 ).

Description.

Shell large (height 69.1-82.9 mm, width 38.3-42.0 mm), chirally dimorphic, solid, and ovate conical shape. Spire elongate conical with pale colour; apex acute without black spot on tip. Whorls 5-7 convex; suture wide and depressed; last whorl ovate. Periostracum brownish to thin corneous. Shell surface generally with irregular and coarse growth lines; very weak to nearly absent of spiral depression area and keel. Shell colour generally rose-pink to stained with dark brown colour below and ~ 1/2 of upper periphery. Parietal callus thickened, white, and dilated at umbilical area. Aperture broadly ovate; inner side of outer wall with yellow or pale brown colour; peristome thickened, expanded, and reflexed but not attached to last whorl; lip whitish. Columella white, straight, or little twisted. Umbilicus imperforate.

Radula. Teeth arranged in anteriorly pointed V-shaped rows. Central tooth monocuspid and short-spatulate with truncated cusp. Lateral teeth bicuspid; endocone small, with wide notch and slightly curved and dull cusp; ectocone large with truncated to blunt cusp. Lateral teeth gradually transformed to asymmetric tricuspid marginal teeth. Outermost teeth with small and curved cusp on endocone and ectocone; mesocone large, with curved cusps (Fig. 4C ).

Genital organs. Atrium very short. Penis slender, conical, and short ~ 1/2 of vaginal length. Penial retractor muscle thickened and inserting on epiphallus close to penis. Epiphallus long and slender tube. Flagellum short, extending from epiphallus and terminating in slightly enlarged tube. Appendix short, slender tube, approximately as long as flagellum, and ~ 1/3 of epiphallus length. Vas deferens slender tube passing from free oviduct and terminating at epiphallus-flagellum junction (Fig. 9A ). Internal wall of penis corrugated, exhibiting series of swollen longitudinal penial pilasters forming fringe around penial wall, and with nearly smooth to weak folds around base of penial verge. Penial verge conical with nearly smooth surface (Fig. 9B ).

Vagina slender, long cylindrical, ~ 2 × longer than penis. Gametolytic duct enlarged cylindrical tube then abruptly tapering to slender tube terminally and connected to gametolytic sac (missing during dissection). Free oviduct short; oviduct compact, enlarged to form lobule alveoli (Fig. 9A ). Internal wall of vagina possesses strong corrugated ridges near genital orifice, ridges become weaker corrugated vaginal pilasters, and swollen with irregularly shaped deep crenelations close to free oviduct opening (Fig. 9C ).

Haplotype network.

There were seven COI haplotypes of A. bozhii in this study, and the highest number of mutational steps in the COI minimum spanning network is ten (Fig. 10 ).

Distribution.

This species is found in Phu Yen Province, Vietnam.

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 4. SEM images of the radula of Amphidromus spp A Amphidromus ingens Moellendorff, 1900 from Ea Sup, Dak Lak, Vietnam (NMNS- 8764 - 100) B Amphidromus asperoides sp. nov. from Ea Tu, Buon Ma Thuat city, Dak Lak, Vietnam (NMNS- 8764 - 001) C Amphidromus bozhii Wang, 2019 from Tuy Hoa, Phu Yen, Vietnam (NMNS- 8764 - 016). Central teeth are marked in yellow. The left and right images show the outer and inner sections of each radula, respectively.

Figure 8. Shells of Amphidromus spp A-C Amphidromus asperoides sp. nov. from Ea Tu, Buon Ma Thuat city, Dak Lak, Vietnam A holotype (NMNS- 8764 - 001) B, C paratypes (NMNS- 8764 - 002 and NHMUK 20230613) D-F Amphidromus bozhii Wang, 2019 D, E specimens from Phu Hoa, Phu Yen, Vietnam (NMNS- 8764 - 009, NMNS- 8764 - 013) F specimen from Tuy Hoa, Phu Yen Vietnam (NMNS- 8764 - 014) G-J Amphidromus ingensoides sp. nov G holotype from Cu'Mta, Mdrak, Dak Lak, Vietnam (NMNS- 8764 - 106) H paratype from Cu'Mta, Mdrak, Dak Lak, Vietnam (NHMUK 20230614) I, J paratypes from Hon Ba, Khanh Son, Khanh Hoa, Vietnam (NMNS- 8764 - 107, NMNS- 8764 - 106).

Figure 9. Genitalia of Amphidromus spp A-C Amphidromus bozhii Wang, 2019 from Tuy Hoa, Phu Yen, Vietnam (NMNS- 8764 - 016), showing A general view of genitalia B interior structures of penis C Interior structures of vagina chamber D, E Amphidromus placostylus Moellendorff, 1900 from Dak Po, Gia Lai, Vietnam (NMNS- 8764 - 217), showing D general view of genitalia E interior structures of penis and vagina chamber. Red dots indicate the shape of the missing gametolytic sac. Green arrows indicate the genital openings. Abbreviations: ap, appendix; e, epiphallus; fl, flagellum; fo, free oviduct; gd, gametolytic duct; ov, oviduct; p, penis; pp, penial pilaster; pr, penial retractor muscle; pv, penial verge; v, vagina; vd, vas deferens; vp, vaginal pilaster

Figure 10. Mitochondrial COI haplotype minimum spanning networks of Amphidromus bozhii Wang, 2019. The size of each circle corresponds to the frequency of that haplotype, also shown as the number in that circle. The bars on the branches indicate the number of mutational steps between haplotypes. Specimen codes correspond to those in Table 1.