Sinoennea copiaensis, Sang & A new species of diapherid snail in the genus Sinoennea Kobelt & Province & Sinoennea copiaensis & species & Three apertural teeth are present & parietal & basal & This new species is similar to Sinoennea hippocrepis & Bavay & Dautzenberg & whorls & This is the first species of genus Sinoennea to be reported from Son La province, 2015

Sang, Do Duc, A new species of diapherid snail in the genus Sinoennea Kobelt, Do Van Nhuong Abstract., Province, is described from Son La, Sinoennea copiaensis, Northwestern Vietnam., species, new, Three apertural teeth are present, has a cylindrical glassy white shell sculptured with regularly spaced axial ribs. The parietal side of the peristome extends over part of the penultimate whorl., parietal, including one large, basal, one, This new species is similar to Sinoennea hippocrepis, one columellar., Bavay, Dautzenberg, whorls, but clearly differs from the latter by its larger shell with more & This is the first species of genus Sinoennea to be reported from Son La province, an additional parietal tooth., 2015, A new species of the genus Sinoennea Kobelt, 1904 (Pulmonata: Diapheridae) from Son La, Northwestern Vietnam, Raffles Bulletin of Zoology 63, pp. 490-493 : 491-493

Sinoennea copiaensis , new species

( Fig. 2A–E , Table 2)

Material examined. Holotype: SORC 1130 ( Fig. 2 ). Measurements : shell height (SH) 13.56 mm, shell width (SW) 3.43 mm; type locality: limestone karst in Copia Natural Reserve , Thuan Chau District, Son La Province, Northwestern Vietnam (21°25’25”N, 103°31’18”E, 1.246 m) , Non-type material examined. Limestone forests in Quyet Thang, Co Noi , Mai Son , Son La (21°19’23”N; 104°08’12”E; 687 m): SORC 1132 (5 shells), HNUEM (3 shells), coll. Phung Thi Ngoc & Do Duc Sang, 25 September 2013 ; Natural forest in Pa Kha, Long Luong , Van Ho , Son La (20°46’35”N; 104°50’48”E; 1.017 m): SORC 1133 (12 shells), HNUEM (4 shells), coll. Vu Thu Phuong & Tran Thi Quynh, 5 August 2014 ; Limestone forests in Na Hoi, Chieng Khoang , Quynh Nhai , Son La (21°33’20”N; 103°41’06”E; 376 m): SORC 1134 (8 shells), coll. Do Duc Sang, 16 September 2014 ; Limestone mountain in Nang Phai, Muong Bu , Muong La, Son La (21°28’26”N; 103°01’34”E; 721 m): SORC 1135 (13 shells), coll. Do Duc Sang & Nguyen Thanh Lap, 27 October 2013 .

Etymology. The specific epithet is derived from the type locality of this new species, the Copia Natural Reserve, Son La Province.

Diagnosis. Shell high-spired, cylindrically pupiform with regular vertical ribs; glassy white and shiny. Parietal side of the peristome extended over a part of the penultimate whorl. Umbilicus narrow, hidden by the last part of the last whorl. Aperture oblique, quadrangular with rounded angles. Peristome smooth, continuous; lip thickened and expanded. Aperture with one large parietal tooth, which points towards the basal tooth.

Description. Shell small to medium sized (SH 11.00– 14.60 mm, SW 3.10–4.02 mm, AH 3.10–3.40 mm, AW 2.51–2.90

mm (see also Table 2), dextral, high-spired cylindrically pupiform, glassy, rather transparent and shiny ( Fig. 2A–D ). Apex obtuse, apical whorls smooth. Profile of shell whorls slightly convex, sculptured with closely set regular axial ribs numbering about 50–52 on the last whorl, 4 ribs or more partially obscured by the parietal callus; suture distinct and deep. Umbilical ribs, which are continuations connect of the external ribs of the last whorl are axially aligned and crowded, and extend into the umbilicus. Shell whorls numbering 12 to 13, and regularly increasing in height towards the last whorl. Umbilicus narrow, almost hidden by the last part of the last whorl and reflected outer lip. Aperture oblique, quadrangular with rounded angles. Peristome smooth, continuous, the leading edges thickened and expanded into a reflected lip ( Fig. 2E ). Aperture with one large tooth projecting from the middle of parietal side and pointing towards the basal tooth (B). The basal tooth (B) is set deeply in the aperture, and on the columellar side is one plate-like tooth (pC) that lies well inside the aperture ( Fig. 2E ).

Distribution. The new species is known from several limestone karsts in Son La Province, Northwestern Vietnam: Mai Son District, Co Noi Commune; Thuan Chau District, Copia Natural Reserve; Muong La District, Muong Bu Commune; Quynh Nhai District, Chieng Khoang Commune; Van Ho District, Long Luong and Van Ho Commune ( Fig. 1 ).

Remarks. Sinoennea copiaensis , new species, belongs to the group with cylindriform shells. The new species differs from congeners in Vietnam by its larger shell with more whorls. The shell shape of the new species is fairly similar to S. hippocrepis (of which a population was discovered at Lai Chau Province), but S. copiaensis has an additional apertural tooth. Compared to other congeneric species from Vietnam ( S. atomaria , S. calva , S. macrodonta , S. ovulum , and S. plagiostoma ), China ( S. fuchsi and S. longtanensis ), Thailand ( S. loeiensis and S. stunensis ), and Malaysia ( S. perakensis and S. tiarella ), the shell of S. copiaensis possesses distinctly more whorls (12 to 13 whorls) than the others (see Table 3). Sinoennea copiaensis , new species, also differs from all other Sinoennea species known from China, Thailand and Malaysia by its larger shell. Sinoennea copiaensis , new species, shows little intraspecific conchological variation, except for shell size (see Table 2).

Figures

Fig 1. Map showing the type localities of known species of Sinoennea from Vietnam with Copia Natural Reserve, Thuan Chau District, Son La Province, Vietnam, the type locality of Sinoennea copiaensis n. sp., marked with a star: 1, S. atomaria; 2, S. calva; 3, S. copiaensis; 4, S. hippocrepis; 5, S. macrodonta; 6, S. ovulum; 7, S. plagiostoma.

Fig. 2. Sinoennea copiaensis, new species, holotype (SORC 1130) ((SH 13.56 mm, SW 3.43 mm, AH 3.11 mm, AW 2.85 mm): A, apertural view; B and D, side view; C, dorsal view; E, close up view of the aperture (P, parietal tooth; pC, plate-like tooth; b, basal tooth).