Glessula mandalayensis Man & Ablett & Lwin & Sutcharit & Panha 2024, sp. nov.
Creators: name: Man, Nem Sian
name: Ablett, Jonathan D.
name: Lwin, Ngwe
name: Sutcharit, Chirasak
name: Panha, Somsak
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Subulinidae
Glessula
Glessula mandalayensis

description: 14Glessula mandalayensisMan & Panha sp. nov.
Figs 8 E, F, 9, Tables 1, 3
Type specimens.
Holotype CUMZ 13072 (height 14.6 mm, width 7.1 mm; Fig. 8 E), paratypes CUMZ 13073 (29 shells; Fig. 8 F), NHMUK 20230922 (2 shells) and SMF (2 shells).
Type locality.
Limestone Hills (Apache Cement Factory), Pyinyaung Village, Meiktila District, Mandalay Region, Myanmar (20 ° 49 ' 39.1 " N, 96 ° 23 ' 35.1 " E).
Etymology.
The specific name mandalayensis is the name of region, where the type specimens of this species were collected.
Diagnosis.
Shell large, globosely ovate; spire broad, almost cylindrically attenuated, turreted; last whorl largest; shell surface glossy, smooth to shallow grooves; aperture ovately rounded and broad; peristome thin and white.
Description.
Shell globosely ovate, solid, glossy, brown to bright ochraceous colour, and with 6–7 whorls. Apex blunt and large; protoconch ~ 2 whorls with smooth surface; subsequent whorls with smooth to fine radial striations or sometimes with shallow grooves. Spire broad, cylindrically attenuated, turreted; whorls flatly convex; suture deep; last whorl largest. Aperture ovately rounded and broad; peristome white and thin; columella short, concave, and truncated. Umbilicus closed.
Genitalia (n = 1). Atrium very short. Penis evenly broad, stout, and thick muscularly. Epiphallus short, stout, slightly curved triangular shape, thick muscularly, smooth surface, and ~ 1 / 4 of penis length; flagellum absent. Penial retractor muscle long, thickened and attaches laterally at junction of penis and epiphallus. Vas deferens long distinct tube connected between tip of epiphallus and free oviduct and held in position to penis and vagina with weak connective tissue (Fig. 9 A).
Vagina muscularly and nearly as long as penis. Gametolytic duct short and enlarged at base; gametolytic sac small and elliptical in shape. Free oviduct short and stout, and spermoviduct enlarged.
Radula. Each row contains ~ 70 + teeth with half-row formula: central-lateral-marginal teeth (1 – (19–20) – (15–16 +)). Central tooth relatively small, symmetrical tricuspid with pointed central cusp and very small lateral cusps. Lateral teeth bicuspid: endocone long, slender and with pointed tip; ectocone small, pointed tip and located at base of teeth. Latero-marginal teeth gradually reduced in size and asymmetrically bicuspid: endocone short with pointed tip; ectocone small triangle on shape and situated around middle of tooth height. Outermost teeth small and becoming tricuspid; mesocone short and blunt tip; endocone and ectocone very small and pointed tips (Fig. 9 B).
Distribution.
This new species is known only from the type locality.
Differential diagnosis.
Glessula mandalayensis sp. nov. can be distinguished from other congeners in Myanmar by having the largest and most globosely ovate shell, obtuse and broad spire, wide aperture, and thinner peristome. In particular, this new species differs from a sympatric species, G. feddeni, by having a larger size (height 13.3–16.0 mm; Table 1), more rounded shell, obtuse and broader turreted spire, wider aperture, thinner peristome, and smoother shell surface. In comparison, G. feddeni is smaller in size (height 7.8–10.8 mm; Table 1), with a more solid, slender conical shell, pointed and narrow spire, smaller aperture, thicker peristome, and with distinct grooves on the shell surface. Glessula mandalayensis sp. nov. can also be separated from G. latestriata by its broader shell, wider spire, and blunt apex with smoother shell surface. Whereas G. latestriata has a slenderer shell, narrowly attenuated spire and pointed apex with distinct radial grooves striations. This new species also differs from G. gemma by having a larger and globosely ovate shell (height 13.3–16.0; Table 1), more turreted spire, convex whorls, vertically elongated aperture, and deeper suture. Whereas G. gemma possesses a smaller and slender shell (height 8.7–9.2; Table 1), spire high conical, flatly convex whorls, more rounded aperture, and shallow suture.
Additionally, this new species differs from G. crassilabris s. s. from India and its variety from Rakhine State, Myanmar, in having a smoother shell, obtuse, and lower and broader spire. While G. crassilabris s. s. (Fig. 5 E, F) displays stronger striations and a narrowly pointed spire (Blanford 1865).
Remark.
So far, the genitalia of eight Glessula species has. The terminal part of the male genitalia of G. mandalayensis sp. nov. (Fig. 9 A) clearly differs from these eight species in having no flagellum, while a flagellum is well-developed with a comb-like shape in the others (Table 3). However, we examined only a single specimen; therefore, the extent of variability within the species remains unknown.
description: Published as part of Man, Nem Sian, Ablett, Jonathan D., Lwin, Ngwe, Sutcharit, Chirasak & Panha, Somsak, 2024, Contributions on a small collection of the former Subulinidae Fischer & Crosse, 1877 (Eupulmonata, Achatinoidea) with catalogue of the Glessula and Rishetia species recorded from Myanmar, pp. 173-239 in ZooKeys 1208 on pages 173-239, DOI: 10.3897/zookeys.1208.116083