Angustopila szekeresi Pall-Gergely & Hunyadi, 2015

Pall-Gergely, Barna, Hunyadi, Andras, Vermeulen, Jaap J., Grego, Jozef, Sutcharit, Chirasak, Reischuetz, Alexander, Dumrongrojwattana, Pongrat, Botta-Dukat, Zoltan, Oerstan, Aydin, Fekete, Judit & Jochum, Adrienne, 2023, Five times over: 42 new Angustopila species highlight Southeast Asia's rich biodiversity (Gastropoda, Stylommatophora, Hypselostomatidae), ZooKeys 1147, pp. 1-177 : 1

Angustopila szekeresi Pall-Gergely & Hunyadi, 2015

Fig. 56

Angustopila szekeresi Páll-Gergely et al., 2015a: 42-45, fig. 5.

Type locality.

"China, Guangxi (广西), Hechi Shi (河池市), Bama Xian (巴马县), cliffs at the southern edge of Jiaole Cun (交乐村), 590 m, 24°7.045'N, 107°7.847'E."

Material examined.

Vietnam • 1 figured + 1 juvenile shell; Thanh Hoa Province, Pu Puong National Park, limestone hill near small native village Am (locality code: WMVT.0344); 20°27.39'N, 105°13.65'E; 21 Sep. 2003; W.J.M. Maassen leg.; RMNH.5006720 • 59 adult + 36 j/b shells; Thanh Hóa Province, Như Thanh District , H ải Vân, Hang Lo Cao Khang Chi ến, vicinity of the cave (locality code: 2020/41); 19°37.08'N, 105°34.63'E; 20 m a.s.l.; 14 Feb. 2020; A. Hunyadi leg.; coll. HA • 26 adult shells; Thanh Hóa Province, Như Thanh District , 600 m south from Xuân Khang along road no. 45, around the cave temple (locality code: 2020/40); 19°40.35'N, 105°31.07'E; 80 m a.s.l.; 14 Feb. 2020; A. Hunyadi leg.; coll. HA • 288 adult + 122 j/b shells; Thanh Hóa Province, Lang Chanh District , Đ ồng Lương, 9.4 km northeast from centre of Lang Chánh towards Làng Thung (locality code: 2020/32); 20°11.52'N, 105°15.59'E; 300 m a.s.l.; 12 Feb. 2020; A. Hunyadi leg.; coll. HA • 3 shells; Sơn La Province, Mộc Châu, Hang Dơi, around the entrance of the cave (locality code: 2020/26); 20°50.96'N, 104°38.34'E; 865 m a.s.l.; 11 Feb. 2020; A. Hunyadi leg.; coll. HA • 12 shells; Hòa Bình Province, Kim Bȏi District, Cao Dương, north of Đ ồng Phú, 58 km from Nho Quan towards Hanoi on the Hồ Chí Minh road (locality code: 2020/47); 20°42.59'N, 105°39.30'E; 10 m a.s.l.; 16 Feb. 2020; A. Hunyadi leg.; coll. HA • 9 adult + 10 j/b shells; Sơn La Province, Yen Chau District , Xã Chi ềng On, B ản Tr ạm Hốc, Hang Nh ả Nhung, around the cave (locality code: 2020/20); 20°59.48'N, 104°11.27'E; 970 m a.s.l.; 9 Feb. 2020; A. Hunyadi leg.; coll. HA • 1 shell; Lạng Sơn Province, H ữu Lũng District, H ữu Liên, cross of roads no. 1B-241, 33.5 km towards Ba Nàng, left side of road (locality code: 2020/52); 21°41.06'N, 106°22.87'E; 220 m a.s.l.; 19 Feb. 2020; A. Hunyadi leg.; coll. HA (with unusually high parietal tooth) • 1 shell; Lạng Sơn Province, H ữu Lũng District, H ữu Liên, 1400 m west from Đȏng Lâm along road no. 241 (locality code: 2020/53); 21°41.91'N, 106°21.77'E; 210 m a.s.l.; 19 Feb. 2020; A. Hunyadi leg.; coll. HA (with unusually high parietal tooth) .

Laos • 141 adult + 42 j/b shells; Udomxai Province, 6.5 km southeast from centre of Na Mor towards Udomxai, Ban Nathong, Tham Nathong , below cave spring (locality code: 2019/118); 20°52.37'N, 101°46.98'E; 635 m a.s.l.; 7 Oct. 2019; A. Hunyadi leg.; coll. HA • 75 adult shells; Udomxai Province, 10 km south of centre of Na Mor, 3.8 km east-southeast of Na Xay , rock wall facing north (locality code: 2019/119); 20°53.37'N, 101°48.96'E; 660 m a.s.l.; 7 Oct. 2019; A. Hunyadi leg.; coll. HA • 12 adult + 6 j/b shells; Luang Prabang Province, 12 km from centre of Nong Khiaw towards Pak Xeng, northeast from Ban Huai Lek , left side of the road (locality code: 2019/115); 20°32.59'N, 102°41.16'E; 5 Oct. 2019; A. Hunyadi leg., coll. HA .

Diagnosis.

A small to medium-sized Angustopila species with conical to slightly conical-globular shell (shell height variable), an adnate peristome, and a weak parietal tooth (sometimes absent).

Measurements (in mm).

H = 0.82-0.96, D = 0.77-0.9, H/D*100 = 96.6-126.5 (n = 50, newly collected populations), RUD = 18.1-25.3 (n = 11); H = 0.88-1.03, D = 0.77-0.89, H/D*100 = 82.5-92.1 (shells from the type locality, n = 6).

Differential diagnosis.

Distinguishable from all congeners (including the widespread A. fabella , which also lives in sympatry) based on the conical-globular shell, the relatively large aperture, and the deeply situated parietal tooth.

Distribution.

Angustopila szekeresi was described from Guangxi Province, China. Here we report this species from several new localities in northern Laos and northern Vietnam (Fig. 57 ).

Remarks.

Most of the newly discovered populations show little variability in terms of shell characters. The only notable samples are 2020/52 and 2020/53 (distance between them is only 2.5 km) in Vietnam, which have an unusually high parietal tooth and a conical (not conical-globular) shell. More material is necessary to infer the taxonomic position of the latter populations because, for both samples, single shells are all we have. For the time being, they are referred to as Angustopila cf. szekeresi . We do not assign these two populations to A. fabella because they are both sympatric with A. fabella (distinguishable based on the larger, proportionally wider shell).

The shells from the type locality are taller than the newly collected ones. However, no other important shell characters are found to be different.

Figures

Figure 56. Synoptic view of shells from different Angustopila szekeresi Pall-Gergely & Hunyadi, 2015 populations.

Figure 57. Distribution of Angustopila szekeresi Pall-Gergely & Hunyadi, 2015.