Abstract
Two new land snail species of the family Enidae, Serina xirong Chen, Dai, Wu & Ouyang sp. n. and Turanena jiuzhaigouensis Chen, Dai, Wu & Ouyang sp. n., are described from Jiuzhaigou County, Sichuan Province, China based on conchological morphology. Serina xirong can be distinguished from congeneric species by its ribbed teleoconch, and Turanena jiuzhaigouensis can be distinguished from congeneric species by its micro, conic, weakly keeled shell without color stripes before body whorl. This discovery further enhances our understanding of the enid species diversity in Sichuan Province.
Introduction
The family Enidae Woodward, 1903, comprises small to large land snails widely distributed in Eurasia, northern Africa and northern Australia (Wu 2018). Sichuan Province is located in southwest China and is one of the most biodiverse regions of Enidae in the country, with approximately 70 recorded species and subspecies, and new species being discovered constantly (Wu & Fang 2012, Wu 2018, Chen 2020). Jiuzhaigou County (Nanping) is one of the most important distribution regions of Enidae in the Sichuan Province, with endemic species having been recorded here since the beginning of the 20th century (Möllendorff 1901, Yen 1939). Upon examination of the specimens collected from Jiuzhaigou County from 2020 to 2023, two undescribed enid species were discovered, belonging to the genera Serina Gredler, 1898 and Turanena Lindholm, 1922. Serina is a group of small sized land snail endemic in western China and characterized by the turreted shell, the connected peristome and the absence of a palatal tooth. It consists of 10 known species: S. belae (Hilber, 1883), S. cathaica Gredler, 1898, S. prostoma (Ancey, 1884), S. egressa Sturany, 1900, S. ser Gredler, 1898, S. subser Gredler, 1898, S. soluta (Möllendorff, 1901), S. vincentii (Gredler, 1898), S. schileykoi Fang & Wu, 2013 and S. denticulata Wu & Xu, 2013 (Fang & Wu 2013, Wu & Xu 2013, Wu 2018). Turanena is a group of small sized land snails widely distributed from west Asia to west China and characterized by the nearly conic shell without any tooth. It consists of 34 known species, five of which are recorded in China: T. diplochila (Möllendorff, 1901), T. kreitneri (Hilber, 1883), T. kuldshana (Martens, 1882), T. microconus (Möllendorff, 1901) and T. zhoupengi Ge & He, 2017 (Ge & He 2017, Wu 2018).
In this study, one new species each of Serina and Turanena are described from two localities of the dry-hot valley in Jiuzhaigou County, Sichuan Province, China. The discovery of the new taxa shows once more the high level of endemism of land snails in Sichuan of China.
Material and methods
Specimens were collected from Jiuzhaigou County, Sichuan Province, China from 2021 to 2023. Measurements were taken with digital callipers to the nearest 0.1 mm. Whorls were counted as described by Kerney and Cameron (1979). Terminology follows Wu (2018). Photographs were taken under a camera and modified in Adobe Photoshop CC 2015 (Adobe Systems, San Jose, U.S.).
Abbreviations
NCU_XPWU: Laboratory of Xiao-Ping Wu, Nanchang University.
Results
Family Enidae Woodward, 1903
Genus Serina Gredler, 1898
Type species. Serina ser Gredler, 1898, by original designation.
Serina xirong Chen, Dai, Wu & Ouyang, sp. n.
https://zoobank.org/9CD136A2-DB2D-407D-8F2B-B714F1466B00
A–B, Serina xirong sp. n., holotype (21_NCU_XPWU_SX01), paratype (21_NCU_XPWU_SX02); C–D, Turanena jiuzhaigouensis sp. n., holotype (21_NCU_XPWU_TJ01), paratype (21_NCU_XPWU_TJ02)
Citation: Animal Taxonomy and Ecology 70, 2; 10.1556/1777.2024.00026
Type localities of Serina xirong sp. n. and Turanena jiuzhaigouensis sp. n
Citation: Animal Taxonomy and Ecology 70, 2; 10.1556/1777.2024.00026
Living specimens of Serina xirong sp. n. and Turanena jiuzhaigouensis sp. n. A, Serina xirong sp. n.; B, Turanena jiuzhaigouensis sp. n
Citation: Animal Taxonomy and Ecology 70, 2; 10.1556/1777.2024.00026
Type material: Holotype: 21_NCU_XPWU_SX01, Shuanghe Town [双河镇], Jiuzhaigou County [九寨沟县], Aba Tibetan and Qiang Autonomous Prefecture [阿坝藏族羌族自治州], Sichuan Province [四川省], China, 104°15′53″E, 33°9′57″N, leg. Zhong-Guang Chen & Yan-Shu Guo, July, 2021. Paratypes: 21_NCU_XPWU_SX02–10, other information same as holotype; 23_NCU_XPWU_SX01–10 leg. Zhong-Guang Chen, Meng-Hua Li & Jin-Sheng Mou, August 2023, other information same as holotype.
Measurements: Shell height 9.7–11.0 mm, shell breadth 4.6–4.9 mm.
Diagnosis: Teleoconch ribbed (vs. smooth in all other congeneric species).
Description: Shell turreted with apex not abruptly pointed; shell most swollen (broadest) at body whorl; dextral; solid; semitranslucent; matte; ribbed; not speckled; not spirally grooved; with 7–7.5 whorls. Whorls flattened. Protoconch whorls smooth; polished. Teleoconch ribbed. Growth lines indistinct. Suture well impressed, with a narrow and indistinct defined band on beneath whorl. Body whorl gradually ascending towards aperture; rounded at periphery; without spiral peripheral depression. Aperture in a plane; ovate; oblique; without tooth; with angular tubercle. The peristome insertions connected, with a shallow channel at upper insertion. Peristome yellowish white and reflexed; sharp. Parietal callus distinct. Columellar margin reflected. Columella vertical; without tooth. Umbilicus narrowly open. Shell multicoloured, with reddish brown background and whitish ribs.
Etymology: The species is named after Xirong, a tribe of ancient China, refer to there is a 2500-year-old rock painting of Xirong on the cliff it inhabits.
Vernacular name: 西戎金丝雀螺 xi rong jin si que luo.
Distribution and ecology. This species is only known from the type locality (Fig. 2). It inhabits on the cliff wall facing the river in the dry-hot valley and often co-occur with Subzebrinus beresowskii (Möllendorff, 1901), Laeocathaica distinguenda Möllendorff, 1899 and Pupinidius sp. (Fig. 3).
Remarks: The assignment of the new species in Serina is supported by its morphology: shell small, turreted, absence of the palatal tooth, peristome connected. Although the genitalia of type specimens are too small and difficult to dissect, its unique shell morphology distinguishes it from all other enid species in China. Only three Chinese Enidae have a ribbed shell: Clausiliopsis clathratus (Möllendorff, 1901), Clausiliopsis senckenbergianus Yen, 1939 and Holcauchen multicostatus Chen, Xie, Wang & Wu, 2024 (Wu 2018, Chen et al. 2024). Serina xirong sp. n. can be easily distinguished from them by absence of any tooth (vs. presence) and the different shell shape.
Genus Turanena Lindholm, 1922
Type species. Buliminus (Pseudonapaeus) herzi Boettger, 1889, by original designation.
Turanena jiuzhaigouensis Chen, Dai, Wu & Ouyang, sp. n.
https://zoobank.org/7C69A144-E14A-45BD-8608-F831FB619ED9
Type material: Holotype: 21_NCU_XPWU_TJ01, Zhangzha Town [漳扎镇], Jiuzhaigou County [九寨沟县], Aba Tibetan and Qiang Autonomous Prefecture [阿坝藏族羌族自治州], Sichuan Province [四川省], China, 103°54′16″E, 33°16′26″N, leg. Zhong-Guang Chen & Yan-Shu Guo, July 2021. Paratypes: 21_NCU_XPWU_TJ02–10, other information same as holotype; 23_NCU_XPWU_TJ01–10, leg. Cheng-Ling Zhu, July 2023, other information same as holotype.
Measurements: Shell height 6.0–7.5 mm, shell breadth 3.5–4.1 mm.
Diagnosis: Shell small, conic, weakly keeled, without color stripes before the last half of the body whorl.
Description: Shell conic with apex not abruptly pointed; shell most swollen (broadest) at body whorl; dextral; fragile; semitranslucent; glossy; not spirally grooved; with 6.75–7.25 whorls. Whorls flattened. Protoconch whorls smooth; polished. Teleoconch smooth; with distinct growth lines. Suture shallow; without a narrow defined band on beneath whorl. Body whorl gradually ascending towards aperture; angulate below periphery; without spiral peripheral depression. Aperture in a plane; truncate-ovate; oblique; without tooth; with very weak angular tubercle. The peristome insertions not connected. Peristome brown and slightly reflexed; sharp. Parietal callus indistinct. Columellar margin reflected. Columella vertical; without tooth. Umbilicus narrowly open. Shell multicoloured; with dark brown background; the last half of the body whorl with weak but distinct whitish stripes.
Etymology: The species is named after Jiuzhaigou County, its type locality.
Vernacular name: 九寨沟图灵螺 jiu zhai gou tu ling luo.
Distribution and ecology: This species is only known from the type locality (Fig. 2). It inhabits on the vertical and exposed high cliff adjacent to the river in the dry-hot valley and often found co-occurring with Bradybaena diplodesma (Möllendorff, 1899) and several unidentified species of minute snails (Fig. 3).
Remarks: Given the wide distribution range and relative poor identification characters, it is probable that Turanena is not monophyletic and requires further study. According to the current generic definition, the assignment of the new species in Turanena is supported by its morphology: shell small, conic, parietal callus very thin, without any apertural or columellar tooth. Even without dissection, its unique shell morphology makes it distinguishable from all the congeners. Turanena jiuzhaigouensis sp. n. can be easily distinguished from all congeneric species in China by the weakly keeled body whorl (vs. rounded) and the different shell shape. Its further distinguished from T. kuldshana and T. zhoupengi by the smaller shell size (Shell height 6.0–7.5 mm vs. 8.9–9.5 mm in T. kuldshana, 9.1–16.0 mm in T. zhoupengi), from T. kreitneri and T. microconus by presence of color stripes only on the last half of the body whorl (presence of color stripes on the post-nuclear whorls); from T. diplochila by the separated peristome insertions (vs. connected).
Acknowledgements
We thank Yan-Shu Guo (Sichuan Academy of Forestry Sciences), Cheng-Ling Zhu (Shanghai), Meng-Hua Li (Sichuan Agricultural University) and Jin-Sheng Mou (Sichuan Agricultural University, China Agricultural University) for assistance in collecting specimens, Min Wu and Ruud Bank for their helpful comments on the manuscript. This study was supported by the National Natural Science Foundation of China (32360132, 31772412), and the Integrated Scientific Expedition on the Jiuzhaigou National Nature Reserve (5132202019000439).
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