Gudeodiscus (Gudeodiscus) giardi giardi (Fischer, 1898)

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 : 18-22

Taxon classification Animalia Stylommatophora Plectopylidae

Gudeodiscus (Gudeodiscus) giardi giardi (Fischer, 1898) Figures 7 E–F, 8A, 9I, 13 L–U, 19, 28B, 29E, 30D, 32C, 35 A–C, 45A

Plectopylis Giardi Fischer 1898a, Bulletin Biologique de la France et de la Belgique, 28: 320-322., Plate 17, Figs 17-21. [ “Cao-Bang”].

Plectopylis Giardi Fischer 1898b, Journal de Conchyliologie, 46: 214-218., Figs 2, 5-6. ["rochers calcaires Déo-Ma-Phuc”].

Plectopylis Giardi Fischer 1899, Bulletin Biologique de la France et de la Belgique, 32: 330-332., Figs 2, 5-6.

Plectopylis giardi , - Gude 1899a, Science Gossip, 5: 332-333., Figs 95 a–e ["Cao-Bang, Tonkin"].

Plectopylis congesta Gude 1899a, syn. n., Science Gossip, 5: 332-333., Figs 96 a–f [ “Tonkin”, "Its exact locality, unfortunately, was not stated."].

Plectopylis giardi , - Gude 1899b, Science Gossip, 6: 76., Fig. 103.

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

Plectopylis (Endoplon) congesta , - Gude 1899c, Science Gossip, 6: 148.

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

Plectopylis (Endoplon) congesta , - Gude 1899d, Science Gossip, 6: 175, 176.

Plectopylis congesta , - Gude 1901a, Journal de Conchyliologie, 49: 199, 202, 209, 211-212. ["Entre Bac-Kan, et Nac-Ri; environs de Bac-Kan; That-Khé”].

Plectopylis Giardi , - Gude 1908, Journal de Conchyliologie, 55: 346-348., Figs 1 a–b [ “Cao-Bang”, “Quang-Huyen”].

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

Gudeodiscus giardi giardi , - Páll-Gergely & Hunyadi 2013, Archiv für Molluskenkunde, 142 (1): 19-20., Figs 28, 53 a–b, 58 (map).

Types examined.

Haut-Tonkin, Cao-Bang, leg. Billet, M., MNHN 9946 (2 syntypes of giardi , Figure 8A); Vietnam, Tonkin, environs de Bac-Kan, leg. Messager, MNHN IM-2010-12120 (syntype of congesta , Figure 8E); Vietnam, Tonkin, environs de Bac-Kan. leg. Messager, NHMUK 1922.8.29.49 (syntype of congesta , Figure 8F).

Museum material examined.

Tonkin, coll. Jetschin ex Bonnet 1900, SMF 341736/2; Tonkin, Möllendorff ex Fulton, SMF 150136/1; Tonkin, coll. Jetschin ex Berlier 1908, SMF 102817/1; Tonkin, environs de Bac-Kan, leg. Messager (n. 28), RBINS/1; Tonkin, Long-Phai, NHMSB 122815/1; Long-Phai, leg. Messager, 1901, MNHN-IM-2012-2231/13; Nga-Son, leg. Messager, MNHN-IM-2012-2235/1; Long-Phai, leg. Messager, 1901, MNHN-IM-2012-2236/16; Quang-Huyen, leg. Mansuy, MNHN-IM-2012-2238/14; Bac-Kan, leg. Messager, MNHN-IM-2012-2239/7; That-Khé, leg. Messager, MNHN-IM-2012-2240/9; Bac-Kan, leg. Messager, MNHN-IM-2012-2246/8; Quang-Huyen, Ha-Lang, Coll. Mansuy, MNHN-IM-2012-2248/14; That-Khé, coll. Letellier 1949, MNHN-IM-2012-2266/1; Than-Moi, coll. Staadt, 1969, MNHN-IM-2012-2278/1; Tonkin, coll. Letellier, 1949, MNHN-IM-2012-2293/1; Tonkin, coll. Mansuy, MNHN-IM-2012-2298/1; Entre Bac-Kan et Nac-Ri, coll. Lavezzari, 1929, MNHN-IM-2012-2302/6; Tonkin, coll. Letellier, 1949, MNHN-IM-2012-2308/1; Tonkin, coll. Levazzari, 1929, MNHN-IM-2012-2309/3; That-Khé, leg. Messager, MNHN-IM-2012-2310/6; Cao-Bang, leg. Messager, MNHN-IM-2012-2469/7; Tonkin, leg. Messager, MNHN-IM-2012-2460/9; Tonkin, leg. Messager, MNHN-IM-2012-2441/1; Halong Bay, leg. Messager, MNHN-IM-2012-2318/1; Halong Bay, leg. Messager, MNHN-IM-2012-2319/1; Halong Bay, leg. Messager, MNHN-IM-2012-2323/1; Tonkin, Bac-Kan, Na-Ri, leg. Messager, MNHN-IM-2012-2324/47; That Khé, leg. Messager, MNHN-IM-2012-2326/3; Po Ma, leg. Messager, MNHN-IM-2012-2328/7; That Khé, coll. Staadt 1969, MNHN-IM-2012-2330/3; That Khé, leg. Messager, MNHN-IM-2012-2341/28; Po Ma, leg. Messager, MNHN-IM-2012-2342/6; Col de Nuages, leg. Messager, MNHN-IM-2012-2343/4; Bac-Kan, leg. Messager, MNHN-IM-2012-2344/8; Tonkin, leg. Messager, MNHN-IM-2012-2345/8; That Khé, leg. Messager, MNHN-IM-2012-2346/5; Cold de Nuages, leg. Messager, MNHN-IM-2012-2349/4; Quang-Huyen, coll. Staadt, 1969, MNHN-IM-2012-2351/1; Tonkin, leg. Messager, MNHN-IM-2012-2352/10; Tonkin, leg. Messager, MNHN-IM-2012-2355/1; Na-Cham, leg. Messager, MNHN-IM-2012-2356/10; Na-Cham, leg. Messager, MNHN-IM-2012-2357/5; Cao-Bang, leg. Messager, MNHN-IM-2012-2359/4; That-Khé, leg. Messager, MNHN-IM-2012-2374/4; Tinh Tuc, secteur de Nguyen Binh, coll. Achat Boubée, MNHN-IM-2012-2385/1; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2393/1; Tonkin, coll. Jousseaume, MNHN-IM-2012-2399/1; Bac-Kan, leg. Messager, MNHN-IM-2012-2432/1; Tonkin, leg. Messager, MNHN-IM-2012-2426/3; Bac-Kan, leg. Messager, MNHN-IM-2012-2435/1; Tonkin, coll. Lucas, Acc. no. 2351, NHMUK 20130604/2 (under the name " persimilis "); Tonkin, 3/10/08, NHMUK 20130605/2 (under the name " persimilis v. minor "); Tonkin, That-Khé, 3/10/08, NHMUK 20130606/3 (under the name " persimilis "); Tonkin, coll. Lucas, Acc. no. 2351, NHMUK 20130607/1; Tonkin, 27/6/00, 28, NHMUK 20130608/3 (" congesta "); Tonkin, Phi-Mi, coll. Salisbury ex Beddome, NHMUK 20130609/2 (" congesta "); Tonkin, coll. Kennard, A. S. ex Gude, NHMUK 20130610/1 (" congesta "); Tonkin, Quang-Huyen, NHMUK 1916.3.16.21/1; Tonkin, Quang-Huyen, NHMUK 1907.2.20.17-18/2; Haut-Tonkin, NHMUK 1904.8.1.1-2/2 (under the name " persimilis "); Tonkin, That-Khé, NHMUK 1900.2.13.221/1; Tonkin, That-Khé, NHMUK 1920.1.20.17/1; Tonkin, Long-Phai, coll. Wagner ex Messager, NHMW 71640/O/10289/1; Tonkin, Ngan-Son, coll. Wagner ex Messager, NHMW 71640/O/10288/1; Tonkin, Phi-Mi, NHMW 46023/2; Tonkin, Long-Phai, NHMW 46294/2; Tonkin, That-Khe, coll. Wagner ex Messager, NHMW 71640/O/10286/1; Tonkin, Po-Ma (?), coll. Wagner ex Messager, NHMW 71640/O/10287/1; Tonkin, Bac-Khuon, coll. Rolle, NHMW 103352/1 (mixed sample with phlyarius ); Tonkin, Quang-Huyen, coll. Steenberg, ZMUC-GAS-1813/2.

New material examined.

Vn10-58 Cao Bằng Province, ca. 31.5 km from Phục Hòa to Mã Phục (left off rd.), 22°42.212'N, 106°22.055'E, leg. Hemmen, Ch. & J., 20.3.2010., PGB/1; Vn10-61 Cao Bằng Province, ca. 2 km from Quảng Uyên to Hạ Lang (right off rd.) 22°42.685'N, 106°27.232'E, leg. Hemmen, Ch. & J., 24.3.2010., PGB/2; Vn10-59 Cao Bằng Province, ca. 30 km from Phục Hòa to Mã Phục (right off rd.), 22°41.787'N, 106°22.652'E, leg. Hemmen, Ch. & J., 23.3.2010., PGB/3; Vn09-23 Cao Bằng Province, ca. 4.5 km from Mã Phục to Cao Bằng (NW of Cao Bằng), ca. 400 m, 22°42.814'N, 106°19.630'E, leg. Hemmen, Ch. & J., 16.10.2009., PGB/4; Vn10-57 Cao Bằng Province, ca. 4.5 km from Mã Phục to Cao Bằng (left off rd.), 22°42.661'N, 106°19.627'E, leg. Hemmen, Ch. & J., 23.03.2010., PGB/3; 20081115D Cao Bằng Province, Hòa An District, Nguyễn Huệ Commune, Hạ Lang, ca 390 m, 22°42.703'N, 106°19.606'E, leg. Ohara, K., 15.11.2008., OK/6, PGB/1; 20081116C Cao Bằng Province, Trùng Khánh District, Cảnh Tiên Commune, Pắc Rảo., ca 545 m, 22°48.941'N, 106°30.549'E, leg. Ohara, K., 16.11.2008., OK/7, PGB/2; Vn10-69 Cao Bằng Province, ca. 34.5 km from Cao Bằng to Đông Khê (left off new rd.), 22°27.439'N, 106°24.994'E, leg. Hemmen, Ch. & J., 26.03.2010. (typical " congesta "), PGB/3; 2011/81 Cao Bằng Province, Đèo Mã Phục (pass) 500 m towards Quảng Uyên, left side of the road, rock cavern, 610 m, 22°43.981'N, 106°20.333'E, leg. Hunyadi, A., 14.11.2011., HA/26, PGB/2; 2011/82 Lạng Sơn Province, Lũng Phầy (pass), Thất Khê N 13 km, 475 m, 22°20.363'N, 106°27.098'E, leg. Hunyadi, A., 15.11.2011., HA/8, PGB/1 (typical " congesta "); 2011/83 Cao Bằng Province, Đèo Lũng Phầy (pass) 2.5 km towards Đông Khê, right side of the road, 360 m, 22°21.654'N, 106°26.467'E, leg. Hunyadi, A., 15.11.2011., HA/17, PGB/2 (typical " congesta "); 2011/86 Cao Bằng Province, Quảng Uyên N, 206-207 cross, 300 m towards Hạ Lang, right side of the road, 445 m, 22°42.670'N, 106°27.260'E, leg. Hunyadi, A., 16.11.2011., HA/14, PGB/1; 2011/87 Cao Bằng Province, Quảng Uyên N, 206-207 cross, 430 m, 22°42.737'N, 106°27.223'E, leg. Hunyadi, A., 16.11.2011., HA/14, PGB/1 (anatomically examined, Figures 19, 28B, 29E, 30D, 32C, 35 A–C); 2011/88 Cao Bằng Province, Quảng Uyên NW, 445 m, 22°42.562'N, 106°26.313'E, leg. Hunyadi, A., 16.11.2011., HA/6; 2011/89 Cao Bằng Province, Quảng Uyên W, Phi Hải-Ðầu Tuyền cross, 500 m, 22°42.188'N, 106°26.358'E, leg. Hunyadi, A., 16.11.2011., HA/5; 2011/90 Cao Bằng Province, Quảng Uyên S 2 km towards Hồng Ðịnh, left side of the road, 470 m, 22°40.761'N, 106°26.746'E, leg. Hunyadi, A., 16.11.2011., HA/1; 2012/42 Cao Bằng Province, Quảng Uyên 10 km towards Cao Bằng, left side of the road, 620 m, 22°42.772'N, 106°21.582'E, leg. Hunyadi, A., 27.05.2012., HA/9; 2012/43 Cao Bằng Province, Pắc Rảo, Cảnh Tiên Commune cross, 300 m towards Trùng Khánh, right side of the road, 530 m, 22°49.385'N, 106°30.742'E, leg. Hunyadi, A., 28.05.2012., HA/13; 2012/44 Cao Bằng Province, southern edge of Pắc Rảo, Trùng Khánh 3 km towards Quảng Uyên, left side of the road, 570 m, 22°48.961'N, 106°30.533'E, leg. Hunyadi, A., 28.05.2012., HA/35; 2011/85 Cao Bằng Province, Cao Bằng 34.5 km towards Đông Khê, left side of the road, 500 m, 22°27.487'N, 106°25.047'E, leg. Hunyadi, A., 15.11.2011., HA/35, PGB/5 (typical " congesta "); 2011/84 Cao Bằng Province, Đông Khê 3 km towards Đèo Lũng Phầy (pass), right side of the road, 390 m, 22°24.223'N, 106°25.937'E, leg. Hunyadi, A., 15.11.2011., HA/10, PGB/2 (typical " congesta "); Cao Bằng Province, Hòa An District, Nguyễn Huệ Commune, small hill just outside of Khau Trang Village, 22°33.510'N, 106°10.294'E, leg. Naggs, F. et al., 22.06.2011., NHMUK/1 (see Figure 45A).

Diagnosis.

Shell small to large, brownish (some Chinese populations are small and yellow, translucent), usually finely reticulated (resulting in a matt surface), umbilicus deep, dorsal side domed; apertural lip, callus and apertural fold very well-developed (Figure 9I). Parietal wall with two lamellae; the anterior one is usually connected to the lower plica; middle palatal plicae short, depressed Z-shaped, or almost vertical, sometimes connected to each other (Figures 13 L–U).

Measurements

(in mm): D = 13.5-14.1, D = 7-7.7 (n=2, 2011/84); D = 15.6-17, H = 7.7-10 (n=2, 2011/85); D = 19.9-20.3, H = 11-11.6 (n=2, 2011/81); D = 21.3, H = 12.1 (n=1, 2011/86).

Differential diagnosis.

This species is most similar to Gudeodiscus francoisi . For comparisons, see under that species. Gudeodiscus dautzenbergi is larger, flatter, has wider umbilicus, a weaker apertural lip and the lower end of the anterior lamella is very much elongated anteriorly. Gudeodiscus villedaryi is also flatter and most populations have a keel around the umbilicus and an additional long plica below the parietal lamellae. Gudeodiscus phlyarius is usually flatter, has a wider umbilicus, slimmer peristome and lower callus. Most specimens of Gudeodiscus phlyarius have separated anterior lamella and lower plica, whereas these are always connected in Gudeodiscus giardi giardi . Typical Plectopylis verecunda shells (synonym of Gudeodiscus phlyarius ) also have an elevated spire, but their shell shape is rather conical, whereas it is usually domed (rounded) in Gudeodiscus giardi .

Intraspecific diversity.

Two subspecies of Gudeodiscus giardi were described from China (see Páll-Gergely and Hunyadi 2013). The populations assigned to the nominotypical subspecies show larger variability in China in terms of shell size, colour and shape, than in Vietnam. In Vietnam Gudeodiscus giardi giardi is moderately variable. Most variability is observable in the formation of the parietal plicae and lamellae (see Remarks and Figures 13 L–U).

Description of the genitalia.

One specimen was anatomically examined (see also Remarks). Locality: Cao Bằng Province, Quảng Uyên N, 206-207 cross, 430 m, 22°42.737'N, 106°27.223'E, leg. Hunyadi, A., 16.11.2011. (Figure 28B, 29E, 30D, 32C).

Penis very short, almost ball-like; penis wall conspicuously thickened, its inner surface is characterized by transversal lines at the proximal part and longitudinal pockets in the distal part, arranged in a straight row (Figure 28B); there are some calcareous, claw-like objects in the pockets; the claws have a wide, rounded basal part which is found within the pockets, and the short, hook-like part hangs out of the pockets; the base had a granulated surface, probably to provide a better attachment to wall of the pockets, whereas the tip was smooth (Figure 30D); epiphallus C-shaped, longer than the penis; its inner wall with three longitudinal parallel folds (Figure 29E); penis and epiphallus connected with weak membrane; penial caecum approximately as long as the penis; it has low tubercles on the inner wall and small calcareous rounded granules on each tubercle; retractor muscle attaches on the distal part of the penial caecum; it is longer and wider than the caecum; vas deferens convoluted near the vagina. Vagina very thick and long, it is attached to the body wall with several thin ligaments; one side of the vaginal bulb with very much thickened wall, the other side with thin, almost translucent wall, internally with fine, irregular, reticulated sculpture; inner wall of the distal portion of the vagina with well-developed, rather irregular transversal folds (Figure 32C); gametolytic sac and diverticulum slender, they are nearly the same length.

Radula.

See Table 6 and Figures 35 A–C.

Distribution

(see Figure 42): Newly-collected material was examined from Cao Bằng Province and the northern part of Lạng Sơn Province. The localities of "Col de Nuages" and "Halong Bay" are probably erroneous. This species is also known from the western part of Guangxi, China ( Páll-Gergely and Hunyadi 2013).

Remarks.

Plectopylis congesta Gude, 1899 was described without exact locality data. Some shells from populations in southern Cao Bằng and northern Lạng Sơn prefectures (Vn10-69; 2011/84, 2011/83, 2011/82, 2011/85) resemble the holotype of Plectopylis congesta on the basis of relatively weak peristome and callus, weak (low) posterior lamella and the anterior lamella which is fused to the upper parietal plica. These populations however, falls within the morphological range of the very variable Gudeodiscus giardi giardi , therefore Plectopylis congesta is here synonymised with Gudeodiscus giardi giardi .

The genital anatomy of a Chinese specimen of Gudeodiscus giardi giardi was described by Páll-Gergely and Asami (2014). The only notable difference between the Chinese and Vietnamese specimens is the much longer penis in the Chinese individual. It seems that the long, slender, proximal portion of the penis visible in the Chinese specimen is entirely missing in the Vietnamese one.