Erhaia wangchuki Gittenberger, Sherub & Stelbrink, 2017

Gittenberger, Edmund, Leda, Pema, Wangchuk, Jigme, Gyeltshen, Choki & Bjoern Stelbrink,, 2020, The genera Erhaia and Tricula (Gastropoda, Rissooidea, Amnicolidae and Pomatiopsidae) in Bhutan and elsewhere in the eastern Himalaya, ZooKeys 929, pp. 1-17 : 6

Erhaia wangchuki Gittenberger, Sherub & Stelbrink, 2017 Figs 6 , 7 , 12

Erhaia wangchuki Gittenberger, Sherub & Stelbrink, 2017a: 23 ("district Wangdue Phodrang, Gangchhu, 2883 m a.s.l.; 27°26'N, 90°11'E "). Gittenberger et al. 2017b: 43, fig. 28. Gittenberger et al. 2017c: 900, 903, figs 9, 10.

Material examined.

Holotype. Bhutan • District Wangdue Phodrang, Gangchhu, 2883 m a.s.l.; 27°26'N, 90°11'E; Jigme Wangchuk leg. 21.III.2015; shell; NBCB1013. Paratypes. 2 shells; same data as for holotype; NBCB1014. Additional specimens from the type locality: 23 shells and 88 specimens in ethanol 70%, 10 specimens in ethanol 97%, E. Gittenberger, Choki Gyeltshen & Pema Leda leg. 22.X.2018; NBCB 1072.

Shell.

Shell conical, with 3- 3½ convex, broadly shouldered whorls, that are separated by a deep suture; a little higher than broad; pale yellowish grey with fine irregular growth lines and some dark brown periostracal ridges, one of which sometimes running from a slightly angled site of the apertural columellar border into the umbilicus. Peristome not reflected. Parietal, columellar and about half the adjoining basal apertural border strongly thickened by a whitish callus. Most specimens with a continuous peristome and a broad umbilical chink. Protoconch with faint spiral lirae; teleoconch without spiral sculpture.

Measurements.

(N = 124): H 1.6-2.1 mm, B 1.3-1.7 mm.

Ecology

(Fig. 12 ). See Gittenberger et al. (2017a) for data about the Gangzetem brooklet and its surroundings. The snails are very common on the pebbles and rocks in the open area near the road, next to the water powered prayer wheel.

DNA data

(Fig. 18 ). A single individual (GenBank acc. nos. KY798003 and MT237715, for 16S rRNA and COI, respectively) is genetically distinct from E. jannei (see data for that species) and showed genetic distances of 2.74% for 16S rRNA and 11.43% for COI compared to Erhaia sp. from China, Guangxi (GenBank acc. nos. KC832722 and KC832701).

Notes.

Only three relatively large shells form the type series of this species. Many more specimens, none of which exceed 1.7 mm in breadth and over 2.0 mm in height, were collected recently. This necessitated some adaptations in the description of the shells. Contrary to the original description, the shell should be described as higher than broad.

Erhaia in Nepal and northern India.

In their monograph on the aquatic molluscs of the Ganga River system Nesemann et al. (2007: 64-65) published short descriptions with drawings only of three Erhaia species from Nepal. We acquired photos of the holotypes of these nominal species, which are compared with the congeneric species from Bhutan and northern India.

Figures

Figure 12. Type locality of E. wangchuki; Bhutan, district Wangdue Phodrang, Gangchhu, Gangzetem brooklet, 2883 m a. s. l. Photo by A. C. Gittenberger-de Groot.

Figure 18. Maximum likelihood tree reconstructed with RAxML BlackBox (Stamatakis et al. 2008; GTR + G substitution model for each partition and 100 bootstrap replicates) based on the 16 S rRNA and COI dataset of Liu et al. (2014) and Guan et al. (2008), with new data in red. Numbers on branches denote bootstrap values> 50.

Figures 2 - 10. Erhaia jannei sp. nov., holotype (2 H 2.25 mm) and paratype (3 H 2.02 mm). Bhutan, district Thimphu, W of Geneykha, brooklet with water powered prayer wheel, 2750 m a. s. l. Photos by J. Goud Erhaia pelkiae sp. nov., holotype (4 H 1.86 mm) and paratype (5 H 1.86 mm). Bhutan, district Thimphu, W of Geneykha, brooklet with water powered prayer wheel, 2750 m a. s. l. Photos by J. Goud Erhaia wangchuki Gittenberger, Sherub & Stelbrink, 2017. Shells from the type locality (6 H 1.98 mm) (7 H 2.03 mm); NBCB 1072. Bhutan, district Wangdue Phodrang, Gangchhu, Gangzetem brooklet, 2883 m a. s. l. Photos by J. Goud 8 Erhaia banepaensis Nesemann & S. Sharma, 2007, holotype (H 1.95 mm); NHMW 103319. Nepal, Central Zone, Kavre district, small forest stream, left tributary of the Chandeswari Khola upstream from Chandeshwari at Banepa. NHMW 9 Erhaia nainitalensis Davis & Rao, 1997, holotype of E. chandeshwariensis Nesemann & S. Sharma, 2007 (H 1.94 mm); NHMW 103315. Nepal, Central Zone, Kavre district, small forest stream, left tributary of the Chandeswari Khola upstream from Chandeshwari at Banepa. NHMW 10 Erhaia sugurensis Nesemann, Shah & Tachamo, 2007, holotype (H 1.95 mm); NHMW 104172. Nepal, Central Zone, Lalitpur district, Godawari, upper reaches of Sugure Khola forest stream, 1700 m a. s. l. NHMW.