Gudeodiscus (Gudeodiscus) villedaryi (Ancey, 1888)

Pall-Gergely, Barna, Hunyadi, Andras, Ablett, Jonathan, Lương, Hao Văn, Fred Naggs, & Asami, Takahiro, 2015, Systematics of the family Plectopylidae in Vietnam with additional information on Chinese taxa (Gastropoda, Pulmonata, Stylommatophora), ZooKeys 473, pp. 1-118 : 40-41

Taxon classification Animalia Stylommatophora Plectopylidae

Gudeodiscus (Gudeodiscus) villedaryi (Ancey, 1888) Figures 8 B–D, 9J, 10B, 13 V–Y, 23, 24, 28 F–G, 30 A–C, 30F, 32D, 35 M–O

Plectopylis Villedaryi Ancey 1888, Le Naturaliste 2 (10): 71-72., Fig. 2. [ “Région de Lang-son et de Bac-ninh"].

Plectopylis villedaryi , - Gude 1897b, Science Gossip, 4: 139., Figs 60 a–b. ["Lang-son and Bac-ninh, Tonkin"].

Plectopylis villedaryi , - Gude 1899a, Science Gossip, 5: 332.

Plectopylis (Endoplon) villedaryi , - Gude 1899c, Science Gossip, 4: 148.

Plectopylis (Endoplon) villedaryi , - Gude 1899d, Science Gossip, 6: 175.

Plectopylis Villedaryi , - Gude 1900, The Annals and Magazine of Natural History, 7 (5): 313.

Plectopylis villedaryi , - Gude 1901c, Journal of Malacology, 8: 116-117., Figs 5 a–e. [ “Than-Moi”].

Plectopylis (Endoplon) choanomphala Möllendorff 1901, Nachrichtsblatt der Deutschen Malakozoologischen Gesellschaft, 33 (5/6): 75. [ “Than-moi”].

Plectopylis (Endoplon) villedaryi , - Gude 1901c, Journal of Malacology, 8: 116-117., Figs 5 a–e. [ “Than-Moi”].

Plectopylis Villedaryi , - Dautzenberg & Fischer 1905a, Journal de Conchyliologie, 53: 93. ["Dong-Trieu, dans les racines des arbustes qui poussent sur des rochers à ceux de la baie d’Along”].

Gudeodiscus villedaryi , - Páll-Gergely & Hunyadi 2013, Archiv für Molluskenkunde, 142 (1): 8.

Types examined.

Haut-Tonkin, NHMUK 1930.9.12.38 (holotype of villedaryi , Figure 8C); Tonking, Than-Moi, collection Möllendorff ex Fruhstorfer, SMF 9279 (lectotype of choanomphala , Figure 8B); Tonking, Than-Moi, SMF 9276 (paralectotype of choanomphala ).

Museum material examined.

Tonkin, Nja-Ba-Thà, coll. Dosch ex Rolle, SMF 172084/4; Tonkin, Mui-Cho, SMF 172095/4; Tonkin, Than-Moi, coll. Ehrmann ex Fruhstorfer, SMF 150133/2; Tonkin, Muc Cho Nja Ba, coll. Jaeckel, S. H., SMF 207680/3; Tonkin, Mui Aro Nja Ba Thà, HNHM 9576/1; Than-Moi, coll. Letellier, 1949, MNHN-IM-2012-2306/3; Than-Moi, coll. Staadt, 1969, MNHN-IM-2012-2321/2; Than-Moi, coll. Staadt, 1969, MNHN-IM-2012-2335/10; Indo-China, coll. Krempf, MNHN-IM-2012-2400/7 juvenile shells; Tonkin, Nju Ba Thá, coll. Rolle, NHMW 50856/2; Tonkin, coll. Fruhstorfer, NHMW 40848/1; Tonkin, Phu-Ty, coll. Edlauer ex Rolle, NHMW 75000/E/7804/2; “China”, coll. Rolle, NHMW 71640/O/12303/1; Tonkin, Moi-Cho-Nja, coll. Rušnov ex Rolle ex Messager, NHMW 92586/2; Tonkin, Than Moi, coll. Edlauer ex Rolle, NHMW 75000/E/7816/3; Tonkin, Nja-Ba-Thá (?), coll. Rušnov ex Blume, NHMW 92584/1; Tonkin, Than-Moi, coll. Rušnov ex Rolle ex Messager, NHMW 92585/1; Tonkin, Than-Moi, coll. Käufel ex Klemm, NHMW 79000/K/17482/2; Tonkin, Cho-Moi, coll. Rolle, NHMW 71640/O/12302/1.

New material examined.

Vn10-47A Thái Nguyên Province, ca. 4 km NE of Đình Cả, Phượng Hoàng Cave, 21°46.554'N, 106°07.210'E, leg. Hemmen, Ch. & J., 18.03.2010., PGB/3; 20090520A Thái Nguyên Province, Võ Nhai District, Phú Thượng Commune, Phượng Hoàng Cave, Mỏ Gà Vill., ca 150 m, 21°46.836'N, 106°07.107'E, leg. Ohara, K., 20.05.2009., OK/15, PGB/4 (anatomically examined, Figures 24, 28G, 32D); Vn10-128 Lạng Sơn Province, ca. 69 km from Thái Nguyên to Bắc Sơn (right side off road), 21°54.270'N, 106°15.801'E, leg. Hemmen, Ch. & J., 22.10.2010., PGB/1; 2012/58 Thái Nguyên Province, northern edge of Lâu Thượng, 5 km W of Ðình Cả, 105 m, 21°44.484'N, 106°01.420'E, leg. Hunyadi, A., 04.06.2012., HA/4; 2011/65 Lạng Sơn Province, Đồng Mỏ 2.5 km towards Văn Quan, right side of the road, 270 m, 21°40.358'N, 106°34.783'E, leg. Hunyadi, A., 10.11.2011., HA/7+2jb, PGB/1; 2011/68 Lạng Sơn Province, Đồng Mỏ 7 km towards Văn Quan, Vạn Linh cross., left side of the road, 370 m, 21°41.158'N, 106°33.588'E, leg. Hunyadi, A., 10.11.2011., HA/1; 2011/76 Lạng Sơn Province, northern edge of Chi Lăng, pass next to the tourist path (N of Đồng Bành) 75 m, 21°34.945'N, 106°30.567'E, leg. Hunyadi, A., 13.11.2011., HA/15+1jb, PGB/2; 2011/79 Lạng Sơn Province, Đồng Mỏ 5.2 km towards Chi Lăng, right side of the road, 40 m, 21°37.215'N, 106°32.538'E, leg. Hunyadi, A., 13.11.2011., HA/3; 2011/102 Thái Nguyên Province, Ðình Cả NE 4 km, Phượng Hoàng cave, around the entrance of the cave, 365 m, 21°46.782'N, 106°07.189'E, leg. Hunyadi, A., 13.11.2011., HA/25+2jb, PGB/2 (anatomically examined, Figures 23, 28F, 30 A–C, 30F, 35 M–O); 2012/38 Lạng Sơn Province, Đồng Mỏ 4-5 km towards Chi Lăng, right side of the old road, 65 m, 21°37.479'N, 106°32.730'E, leg. Hunyadi, A., 25.05.2012., HA/12+1jb; Vn11-159 Lạng Sơn Province, at km 74.8 on road 1B, Đồng Đăng to Thái Nguyên (8 km S Bắc Sơn), 21°54.543'N, 106°17.298'E, leg. Hemmen, Ch. & J., 02.04.2011., HE/1; Vn11-163 Lạng Sơn Province, road 242 from Đình Cả to Hữu Lũng, SE Bình Long, 21°38.424'N, 106°11.761'E, leg. Hemmen, Ch. & J., 02.04.2011., HE/9; Vn11-151 Thái Nguyên Province, ca. 48 km from Thái Nguyên to Bắc Son, near Lâu Thượng (SW Đình Cả), 21°43.522'N, 105°58.662'E, leg. Hemmen, Ch. & J., 29.03.2011., HE/8; Vn11-161 Lạng Sơn Province, at km 90.5 on road 1B Đồng Đăng to Thái Nguyên, 21°49.656'N, 106°12.636'E, leg. Hemmen, Ch. & J., 02.04.2011., HE/1; Vn11-152 Lạng Sơn Province, road 1B, ca. 23 km SE Bắc Sơn (between Đình Cả and Bắc Sơn), 21°49.155'N, 106°11.448'E, leg. Hemmen, Ch. & J, 29.03.2011., HE/3.

Diagnosis.

Shell medium-sized to large, strongly-built, nearly smooth, with thick apertural lip and an oblique, strong apertural fold (Figure 9J); umbilicus frequently keeled. The anterior parietal lamella is supported by an anteriorly elongated lower plica; an additional, long horizontal plica is present near the lower suture; middle palatal plicae oblique (Figures 13 V–Y).

Measurements

(in mm): D = 19.5-21.7, H = 11-12.6 (n=4, Vn11-163); D = 15.4-18.4, H = 7.8-8.9 (n=3, Vn11-151); D = 21-23.4, H = 11.3-12.6 (n=3, Vn11-152); D = 15.4-16.5, H = 8.4-9.5 (n=3, 20090520A); D = 16.7-20.6, H = 8.9-9.8 (n=3, Vn10-42); D = 16.1-17.8, H = 7.9-9.2 (n=2, Vn10-44).

Differential diagnosis.

See under Gudeodiscus dautzenbergi and Halongella schlumbergeri .

Intraspecific diversity.

The morphology of palatal and parietal plicae and lamellae do not show significant variation. Conversely, shell size, aperture shape, shape of the dorsal side of the shell, spire height and the presence or absence of the periumbilical keel show considerable variation across populations. See also Table 11.

Description of the genitalia.

Three specimens were anatomically examined; they were collected at the same locality at different times of the year (20090520A: 20 May, two specimens; 2011/102: 12 November, one specimen). One of the specimens from the 20090520A sample had abnormally developed genitalia. Namely, the penis was “normally” connected to the genital opening, but the vagina was only attached to the atrium area with weak fibres. Nevertheless, the gametolytic sac was filled with fragments of a spermatophore which is an indication of successful mating. An epiphallus was absent and the vas deferens started from the base of the vagina. The other specimen from the 20090520A sample (collected in May) had 18 embryos developed in its uterus, and had no claws between the folds on the inner wall of the penis, whereas the one collected in November was not gravid, but had several claws within the folds inside the penis. The claws had a moderately long base inside the pockets, whereas their hook-like tip was hanging out of the pockets. The SEM images revealed that the base had a granulated surface, probably to provide a better attachment to wall of the pockets, whereas the tip was smooth. Additionally, the specimen from November had parallel, dense, wavy, horizontal folds on the inner wall of the proximal part of the penis, and longitudinal, parallel folds on the distal portion of the penis. The other specimen sampled in May had only a slightly waved proximal part of the longitudinal folds. Other parts of the genitalia did not differ between the two specimens.

The penis is short, pear-shaped internally with pockets standing in a straight row at the distal part of the penis; the epiphallus is much more slender, and is somewhat shorter than the penis; there is no penial caecum, the retractor muscle attaches on the apical part of the penis (at the penis-epiphallus transition); epiphallus approximately as long as the penis, it transforms to vas deferens without obvious boundary; epiphallus internally with parallel folds; vagina long with a well-developed vaginal bulb, it is attached to the body wall with several ligaments; vaginal bulb with thickened wall, internally almost smooth, only with hardly visible longitudinal folds; inner wall of the distal part of the vaginal with low, parallel or converging, serrulate folds (Figure 32D); there is a shorter, thicker gametolytic sac and a longer, more slender diverticulum.

Radula.

See Table 6 and Figures 35 M–O.

Distribution

(see Figure 40). The species is known from Thái Nguyên and Lạng Sơn provinces.

Remarks.

Gudeodiscus villedaryi is a very variable species in terms of shell characters. The species is recognised on the basis of the presence of an additional lower plica, which is absent in Gudeodiscus dautzenbergi . The latter species might be only a variety of Gudeodiscus villedaryi which has lost the lower plica. More information is needed to determine whether the populations assigned to Gudeodiscus villedaryi and Gudeodiscus dautzenbergi form monophyletic groups. See also under Gudeodiscus dautzenbergi .