Oospira stoliczkana (Sykes, 1893)

Man, Nem Sian, Lwin, Ngwe, Sutcharit, Chirasak & Panha, Somsak, 2023, Further notes on the taxonomy of the land snail family Clausiliidae Gray, 1855 (Stylommatophora, Helicina) from Myanmar with description of two new species, ZooKeys 1160, pp. 1-59 : 1

7 Oospira stoliczkana (Sykes, 1893)

Figs 9D-F , 10E-H , 19L

Clausilia vespa - Stoliczka 1872: 209, pl. 9, fig. 15a. (non Gould, 1856)

Clausilia vespa - Pfeiffer 1877: 468 (in part).

Clausilia (Oospira) stoliczkana Sykes, 1893: 166. Type locality: "Tavoy, Burmah" [Dawei, Tanintharyi Region, Myanmar]. Gude 1914: 335.

Oospira (Oospira) stoliczkana - Nordsieck 2002b: 86. Nordsieck 2007: 24.

Oospira stoliczkana - Szekeres et al. 2021a: 178, 179, fig. 9a.

Material examined.

Phra Cave , Tanintharyi Region, Myanmar (11°13'46.2"N, 99°10'34.3"E): CUMZ 13046 (4 shells; Fig. 9D-F ), CUMZ 13047 (1 specimen in ethanol) .

Description.

Shell elongate ovoidal, glossy, translucent, and horny brown; spire blunt. Shell surface with very thin striations to smooth surface; suture wide and distinct. Whorls 6- 6½, convex, regularly growing and bluntly attenuated to apex. Aperture obliquely pear-shaped, basis rounded and narrowing towards parietal sinus; peristome detached, thin and little expanded. Superior lamella developed, sharp, continuous with spiralis and low at transition to spiralis. Inferior lamella steeply ascending, distant from superior lamella and ending at peristome. Subcolumellaris emerged and only visible in oblique view. Principalis running along lateral-dorsal side and anterior end visible through oblique apertural view. Palatal plicae lateral, 8-10: first plica strong and longest; following four plicae parallel and equal in length, and remaining plicae shorter, closer, gradually reduced towards anterior. Clausilium plate lateral side and slightly broad at tip.

Genitalia (n = 1). Atrium (at) short and slender; penis (p) muscular and cylindrical. Epiphallus (ep) muscular, cylindrical, slightly longer by 1.5 × diameter of penis, and broadest at proximal part. Penial retractor muscle (pr) attaches proximally to epiphallus. Vas deferens (vd) slender, and shortly bounded at atrium and penis junction (Fig. 10E ). Internal sculpture of penis consists of two parts: region near atrium, ~ 1/4 length of penis with irregular transverse fleshy folds arranged in nearly V-shaped rows (Fig. 10F ); region near epiphallus becoming smooth with oblique longitudinal folds (Fig. 10G ). Internal sculpture of epiphallus with elevated papillae arranged in nearly oblique rows (Fig. 10H ).

Vagina (v) large, short, and almost half the length of free oviduct (fo). Distal part of pedunculus (dpb) large and long; diverticulum (db) long, ca. same length as dpb; proximal part of pedunculus (ppb) slender, almost equal in length to diverticulum, and bursa copulatrix (bb) small, ovateshape (Fig. 10E ).

Distribution.

This species is known from Mon State, along with its type locality in Tanintharyi Region; no reports have been made outside Myanmar to date ( Szekeres et al. 2021a).

Remarks.

Oospira stoliczkana can be distinguished from all other species with an ovate-fusiform shell ( O. philippiana , O. ovata , O. bulbus , and O. vespa ) by its elongate ovoidal shell, thinner peristome, and 8 to 10 palatal plicae. Although only one ethanol-preserved specimen could be examined, the internal sculpture of the penis and epiphallus of O. stoliczkana differs from O. philippiana , O. bulbus , and O. ovata by its very short V-shaped folds in the region near the atrium and more elevated and pointed papillae in epiphallus.

Some of the examined specimens had a thin and translucent shell, with more distinct palatal plicae.

Oospira species group with long and slender fusiform shell

In Myanmar, this group comprises 15 species including two new ones. Six of these species are examined herein; the remaining nine are O. arakana (Stoliczka, 1872), O. decollata (Likharev, 1962), O. fusiformis (Blanford, 1865), O. gracilior (Hanley & Theobald, 1870), O. insignis (Gould, 1843), O. limborgi Grego & Szekeres, 2021, O. malaisei Nordsieck, 1973, O. mongmitensis Grego & Szekeres, 2021 and O. sardicola Grego & Szekeres, 2021.

Figures

Figure 9. Shell and clausilial apparatus of A-C Oospira ovata, specimen CUMZ 13044 from Pathein Mountain, Mon State A, C shells B clausilial apparatus and D-F Oospira stoliczkana, specimen CUMZ 13046 from Phra Cave, Tanintharyi Region D clausilial apparatus E, F shells. White arrows indicate principalis.

Figure 10. Genital anatomy of A-D Oospira ovata, specimen CUMZ 13045 A whole reproductive system B internal sculpture of penis C transition from penis to epiphallus D internal sculpture of epiphallus and E-H Oospira stoliczkana, specimen CUMZ 13047 E whole reproductive system F internal sculpture of penis G transition from penis to epiphallus H internal sculpture of epiphallus. Yellow arrows indicate approximate transitional position from penis to epiphallus.

Figure 19. Synoptic view of the clausiliid species recorded from Myanmar A Phaedusa lypra, syntype MNHN-IM- 2000 - 2502 - 7 B Oospira magna, lectotype NHMUK 1901.3.17.156 C Oospira malaisei, holotype SMNH 3014 D Indonenia masoni, lectotype NHMUK 1888.12.4.1034 E Phaedusa bocki menglunanensis, specimen NHMUK 1903.7.1.3652 F Oospira mongmitensis, holotype UF 117571 (after Szekeres et al. 2021 b: fig. 1 d) G Oospira ovata, lectotype NHMUK 1906.2.2.378 H Oospira philippiana, possible syntype SMF 62294 / 1 I Oospira sardicola, holotype UF 117570 (after Szekeres et al. 2021 b: fig. 2 c) J Oospira shanensis, holotype NHMUK 1903.7.1.3544 K Phaedusa shanica, lectotype SMF 62260 L Oospira stoliczkana, holotype NHMUK 1888.12.4.1031 M Phaedusa theobaldi, lectotype NHMUK 1888.12.4.1056 N Phaedusa bocki thompsoni, specimen NHMUK 1903.7.1.1163 O Indonenia tuba, lectotype NHMUK 1907.12.30.241 P Oospira vespa, paralectotype MCZ 169456 and Q Oospira zediopsis sp. nov., holotype CUMZ 13064. Photo: P. Maestrati, MNHN (A), A Persson, SMNH (C).