Gudeodiscus (Gudeodiscus) messageri raheemi Pall-Gergely & Hunyadi

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 : 25-28

Taxon classification Animalia Stylommatophora Plectopylidae

Gudeodiscus (Gudeodiscus) messageri raheemi Pall-Gergely & Hunyadi ssp. n. Figures 5D, 5E, 10A, 12 R–V, 20, 28E, 29 F–G, 31B, 35 D–F

Type material.

Thanh Hoa Province, Cam Thuy District, Fish Stream, leg. Naggs, F. & Hao, L.V., 13.05.2008., NHMUK 20110370.1-3 (holotype and two paratype); MAA10 Ninh Bình Province, Cúc Phương Nat. Park, path to fairy cave, approximate GPS position: 20°21'N, 105°54'E, leg. Vermeulen, J., coll. Maassen, W.J.M., 10.10.1998., PGB/1 paratype, WM/3 paratypes; MAA1 Thanh Hóa Province, Pù Luông Nat. Park, NW corner of park near Hang village, limestone area near village, 20°31.84'N, 105°04.76'E, coll. Maassen, W.J.M., 19.09.2003., PGB/1 paratype, WM/3 paratypes; MAA9 Thanh Hóa Province, Pù Luông Nat. Park, limestone hill opposite village Naca, 20°26.86'N, 105°11.57'E, coll. Maassen, W.J.M., 20.09.2003. WM/2 paratypes; Vn10-76A Sơn La Province, ca. 32 km from Mộc Châu to Hà Nội (old road), 20°47.351'N, 104°50.063'E, leg. Hemmen, Ch. & J., 07.10.2010., HE/1 paratype, PGB/2 paratypes; same locality data, leg. Hemmen, Ch., 01.10.2012., HE/1 paratype; Vn10-103 Hòa Bình Province, ca. km 156 old road Hà Nội to Sơn La (right side off road), 20°46.000'N, 104°53.885'E, leg. Hemmen, Ch. & J., 15.10.2010., HE/2 paratypes, PGB/1 paratype, and one paratype in ethanol (anatomically examined, Figure 20); 20080509C Nghệ An Province, Pù Mát Nat. Park, Con Cuông Dist., Lục Dạ Commune, Tân Hợp Village, ca 90 m, 18°57.80201'N, 104°54.67774'E, leg. Ohara, K., 09.05.2008., OK/5 paratypes, PGB/2 paratypes; 20071118A Thanh Hóa Province, Trang Village, Bá Thước. (Bee Cave Mt.), Lân Sa Commune, ca 40 m, 20°19.92147'N, 105°12.49178'E, leg. Ohara, K., 2007.11.18., PGB/1 paratype; 20071118B Thanh Hóa Province, Cây Đăng Cave, Lương Ngọc, Cẩm Lương C., (GPS not recorded), leg. Ohara, K., 18.11.2007., PGB/1 paratype; 20071116C Ninh Bình Province, Cúc Phương Nat. Park, Cave of Prehistoric Man, ca 145 m, 20°15.53843'N, 105°42.38950'E, leg. Ohara, K., 16.11.2007., PGB/2 paratypes; Vn10-104B Sơn La Province, right side off road Mộc Châu to Sơn La, 20°52.567'N, 104°35.310'E, leg. Hemmen, Ch., 02.10.2012., HE/7 paratypes; same data, leg. Hemmen, Ch. & J., 08.10.2010., PGB/2 paratypes; same data, leg. Hemmen, Ch. & J., 14.10.2011., HE/17 paratypes; 2011/106 Ninh Bình Province, Cúc Phương Nat. Park, main entrance, 700 m towards Bống Village, 155 m, 20°15.231'N, 105°42.639', leg. Hunyadi, A., 22.11.2011., HA/12 paratypes +1jb (not paratype), PGB/2 paratypes; 2011/108 Ninh Bình Province, Cúc Phương Nat. Park, Ðộng Người Xưa (=Prehistoric Men Cave), around the cave, 20°17.615'N, 105°40.115'E, leg. Hunyadi, A., 23.11.2011., HA/6 paratypes; 2011/113 Thanh Hóa Province, Cẩm Lương, Ðộng Cây Ðăng (cave), around the cave, 60 m, 20°15.128'N, 105°23.404'E, leg. Hunyadi, A., 25.11.2011., HA/6 paratypes +5jb (not paratypes); 2012/10 Nghệ An Province, Con Cuông 20 km towards Anh Sơn, right side of the road, 40 m, 18°58.302'N, 105°00.796'E, leg. Hunyadi, A., 15.05.2012., HA/7 paratypes +11jb (not paratypes); 2012/60 Sơn La Province, Mộc Châu 5 km to wards Sơn La, right side of the road nr. 6, 755 m, 20°52.551'N, 104°35.318'E, leg. Hunyadi, A., 06.06.2012., HA/6 paratypes +16jb (not paratypes), PGB/1 paratypes; 2012/61 Sơn La Province, Hà Nội 156 km towards Mộc Châu, left side of the road nr. 6, 1100 m, 20°45.993'N, 104°53.868'E, leg. Hunyadi, A., 06.06.2012., HA/3 paratypes +2jb (not paratypes); 2012/62 Sơn La Province, Hà Nội 156 km towards Mộc Châu, right side of the road nr. 6., rocky wall, 1110 m, 20°46.085'N, 104°53.888'E, leg. Hunyadi, A., 06.06.2012., HA/5 paratypes+2jb (not paratypes), PGB/1 paratype; Vn12-80A Thanh Hóa Province, Cẩm Thạch, opp. Cẩm Lương Fishstream (W Cẩm Thủy), 20°15.234'N, 105°23.530'E, leg. Hemmen, Ch., 08.10.2012., HE/5 paratypes; same data, leg. Hemmen, Ch. & J., 04.04.2010., HE/2 paratypes; Vn11-215 Sơn La Province, ca. 34 km from Mộc Châu to Mai Châu, 20°45.219'N, 104°54.458'E, leg. Hemmen, Ch. & J., 15.10.2011., HE/1 paratype; Vn11-230 Nghệ An Province, ca. 1.2 km left off rd 48, ca 23 km from Thái Hòa to Qùy Châu, 19°24.363'N, 105°26.521'E, leg. Hemmen, Ch. & J., 22.10.2011., HE/1 paratype; Vn12-268 Thanh Hóa Province, km 585 on road 15 Yến Cát to Ngọc Lặc 1 km right off road 15, 19°45.589'N, 105°25.521'E, leg. Hemmen, Ch. & J., 14.04.2012., HE/3 paratype; 20080510A Nghệ An Province, Pù Huống Nature Reserve, Con Coung District, Anh Son, Hoi Son, ca 30 m, 18°57.11872'N, 105°02.63029'E, leg. Ohara, K, Okubo, K & Otani, J. U., Sang, 10.05.2008., 1 paratype in ethanol, anatomically examined.

Diagnosis.

Anterior lamella normal or dissolved into small denticles, if normal, the lower plica extends beyond the anterior lamella in the anterior direction (Figures 12 R–V).

Description.

Shell medium in size, light to dark brown or dark yellowish, sometimes almost flat but usually with slightly elevated spire, consists of 6.25-6.75 whorls; suture relatively shallow; protoconch (2.5-2.75 whorls) glossy, very finely, regularly ribbed; teleoconch very finely, rather irregularly ribbed, spiral lines visible mainly at the dorsal side where sometimes they are as strong as the ribs (resulting in a reticulated surface), in some specimens however hardly any spiral lines are visible; sculpture weaker on the ventral side but within the umbilicus are as strong as on the dorsal side; umbilicus relatively narrow and deep; aperture wide with whitish or light brown, thickened and reflexed apertural rim; callus slightly S-shaped, well-developed, with upper and with or without lower canal between the ends of callus and the apertural lip; apertural fold always missing.

More than ten specimens were opened belonging to different populations. Parietal side with two lamellae and upper and lower horizontal plicae above and below the anterior lamella; the lower plica usually extends beyond the anterior lamella in the anterior direction; in some populations the anterior lamella (or only the upper part of the lamella) is dissolved into several denticles. Palatal wall with six plicae; first and last are short and relatively straight, the four middle plicae are usually depressed Z-shaped and in many cases connected to each other with a ridge.

Measurements

(in mm). D = 12.9-14.4, H = 6.2-7.5 (n=3, Vn10-76); D = 14.2-14.4, H = 6.8-7.9 (n=3, 20071116C); D = 12.1, H = 6 (n=1, Vn11-230); D = 16-17.9, H = 7.3-7.9 (n=3, Vn11-104).

Differential diagnosis.

The lower parietal plica extends beyond the anterior lamella in the anterior direction, which is extremely rarely the case in the nominotypical subspecies. The anterior lamella was dissolved into small denticles in many samples, which has never been observed in the nominotypical subspecies (Figures 12 N–Q: messageri , 12 R–V: raheemi ssp. n.). The umbilicus of the new subspecies is narrower, it has more rounded whorls and a sharper, more angled callus, than in most samples of Gudeodiscus messageri messageri .

Gudeodiscus messageri raheemi ssp. n. lives sympatrically with an atypical form of Gudeodiscus phlyarius in Ninh Bình Province (see under Gudeodiscus phlyarius ). Gudeodiscus phlyarius is flat and has an apertural fold, whereas Gudeodiscus messageri raheemi ssp. n. has somewhat elevated spire and always lacks the apertural fold. See also under Gudeodiscus hemmeni sp. n.

Intrasubspecific diversity.

Relatively variable; the colour, spire height, size and morphology of the palatal and parietal lamellae and plicae show considerable variability (see Table 8).

Description of the genitalia.

Two specimens were anatomically examined. Both specimens had embryos developing in their uterus. Localities: “Specimen1”, Hòa Bình Province, ca. km 156 old road Hà Nội to Sơn La (right side off road), 20°46.000'N, 104°53.885'E, leg. Hemmen, Ch. & J., 15.10.2010. (with 3 embryos, Figures 20, 29F, 31B, 35 D–F); “Specimen2”, Nghệ An Province, Pù Huống Nature Reserve, Con Coung District, Anh Son, Hoi Son, ca 30 m, 18°57.11872'N, 105°02.63029'E, leg. Ohara, K, Okubo, K & Otani, J. U., Sang, 10.05.2008. (Figures 28E, 29G).

Penis relatively short and slim, attached to the slightly shorter epiphallus by weak fibres; penis internally with longitudinal folds; the folds are more elevated in the distal part of the penis and they from characteristic “pockets” (Figure 28E); the pockets are arranged in two rows, the upper row (closer the distal end of the penis) is slightly curved on the opened penial wall, but the lower row follows a a wavy line with two peaks; epiphallus have longitudinal folds on the inner wall; penial caecum long; “Specimen1” had two times longer caecum than “Specimen2”; internally with small hollows arranged in longitudinal lines (Figure 29F); “Specimen2” had a few elongated and globular calcareous granules within the hollows (Figure 29G); retractor muscle very long and slim, attaches on the distal end of the penial caecum; vas deferens very long. Vagina extremely long, cylindrical in “Specimen1” and with well-developed vaginal bulb in “Specimen2”; inner wall of the vagina with 6-8 low, parallel or converging folds (Figure 31B); gametolytic sac and diverticulum of the same length, both relatively slim, although the gametolytic sac is a bit swollen.

Radula.

See Table 6 and Figures 35 D–F.

Etymology.

The new subspecies is dedicated to and named after our colleague and much-valued friend, Dinarzarde Raheem.

Type locality.

Thanh Hoa Province, Cam Thuy District.

Distribution

(see Figure 43). The new subspecies is known from several localities in Ninh Bình, Thanh Hóa, Sơn La, Hòa Bình and Nghệ An provinces.