Sinocamaena cheni Wu 2024, gen. et sp. nov.
Creators: name: Wu, Min
name: Chen, Tian
name: Shen, Wang
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Camaenidae
Sinocamaena
Sinocamaena cheni

description: Sinocamaena cheni Wu, gen. et sp. nov.
Chinese name.
陈氏中华坚螺.
Type material.
Holotype: a fully mature living snail, HBUMM 08381 - spec. 1, Zhangjiadi [张家地], Yunhe County [云和县], Lishui [丽水], Zhejiang Province; around oaks in remote forest, 27.974 ° N, 119.379 ° E, c. 820 m a. s. l., 2019 - VIII, coll. Chen, Tian [陈天]; molecular voucher specimen HBUMM 08381 a. Paratypes: five fully mature empty shells, HBUMM 08381 - spec. 2 – 6, same collection data as holotype; HBUMM 08367, a fully mature living snail; Zhangjiadi, Yunhe County, Lishui, Zhejiang Province; oak woods, coll. Chen, Tian; molecular voucher specimen HBUMM 08367 a- 1; HBUMM 08382 - spec. 1, a living snail that reared to maturity at laboratory, same collection data as holotype; a fully mature empty shell, HBUMM 08370 - spec. 1, Mihougu [猕猴谷], Fengyangshan [凤阳山], Longquan County [龙泉县], Lishui, Zhejiang Province; 27.897 ° N, 119.159 ° E, 1100 m a. s. l., 2019 - VIII- 26, coll. Ye, Shi-Han [叶诗涵].
Measurement of holotype.
Shell height 19.2 mm, shell breadth 44.3 mm, aperture height 15.9 mm, aperture breadth 22.2 mm, embryonic shell whorls 1 1 / 4, whorls 4 5 / 8.
Description.
Shell (Fig. 1) large, depressed. Whorls slightly convex. Suture shallowly impressed. Umbilicus broad with embryonic whorls visible, approximately one-fifth of shell major diameter. Bottom-umbilicus transition changed gently. Columella oblique or obliquely curved. Columellar lip slightly covering umbilicus. Protoconch evenly granulate with strong radial sculpture (Fig. 1 C). Teleoconch granulate, without hairs, scales or spiral furrows (Fig. 1 D). Peristome evenly expanded, minutely sinuate. Aperture oblique, slightly expanded. Body whorl large, straight in front, sharply carinate above periphery. Aperture without inner ring-like thickening. Peristome thin, in faint purple. Shell dull and brownish yellow, with many clear thin brown bands above and beneath carina. Measurements (types, N = 8): shell height 17.5–21.0 mm (18.7 ± 1.15 mm), shell breadth 41.2–46.8 mm (43.9 ± 1.89 mm), aperture height 14.2–16.8 mm (15.4 ± 0.86 mm), aperture breadth 20.6–23.8 mm (22.3 ± 1.34 mm), embryonic shell whorls 1–1 1 / 4 (1.125 ± 0.1157 whorls), whorls 4 3 / 8 – 4 5 / 8 (4.531 ± 0.1108 whorls), shell height / breadth ratio 0.41–0.45 (0.43 ± 0.013).
General anatomy (Figs 2 – 4). Externally, a small pore present between ommatophore insertions. Eversible head wart surrounding the pore very weakly present. A mantle lobe present. Tentacles and body in dark leaden-black; sole in color lighter than dorsal side. Jaw arcuate; with 12 more or less projecting ribs (Fig. 3 H). Radula (HBUMM 08367 - spec. 1) comprises numerous transverse rows of teeth, each row containing approximately 131 teeth, 38 + 27 + 1 + 27 + 38. Central tooth symmetrically conic, without cuspid. Lateral tooth about more than two times larger than central tooth, strong conic medially, weakly uni-cuspid at both sides. Marginal teeth gradually changing from broadly tri-cuspid to tetra-cuspid (Fig. 4).
Genitalia (Figs 5, 6). Penial sheath absent. Penis club-shaped, swollen near insertion of penial retractor muscle. Penis externally simple, internally with numerous longitudinal arranged low projections like scales, which do not connect to each other into pilasters along the penial inner wall. Epiphallic papilla rather developed, on side of penial retractor muscle insertion with about several longitudinal pilasters which join apically. Epiphallus very short and stout, internally with a septum longitudinally dividing epiphallus into two separate chambers which one is empty and another one with about 10 pieces of high and low pilasters among which middle one is the strongest (Fig. 6). Flagellum absent. Membranous sac surrounding terminal genitalia absent. Dart sac apparatus absent. Vas deferens thin, slightly thickened near epiphallus. Vagina thick, subequal to penis in length. Bursa copulatrix duct thin, proximally not expanded. Measurement in holotype: P – 9.9 mm; Ep – 2.4 mm; VD – 19.4 mm; PR – 4.8 mm; Va – 7.2 mm; FO – 5.4 mm; BC plus BCD – 55.3 mm.
Ecology.
This species was found in the litter layer in broad-leaved forest where oaks dominate (Fig. 8). However, the rediscovery of this species failed at one of the known localities (Zhangjiadi, Lishui) in April 2023.
Etymology.
This new species is named in memory of Professor Chen De-Niu [陈德牛 Nov 1939 – March 2024], a known malacologist working on Chinese land molluscs. Prof. Chen was one of the doctoral supervisors for Wu M.
Distribution.
Zhejiang (only from type localities: Yunhe, Longquan).
Remarks.
The new species and Camaena vulpis (Gredler, 1887) are superficially similar in having the densely and minutely granulate surface, numerous spiral thin bands and the general shape of shell. However, besides possessing a distinctly larger shell and a higher spire, the latter species has a totally different genital system, which has a long flagellum (HBUMM 08664, Liannan [连南], Nature Reserve of Giant Salamander, Guangdong, China, 2023 - VII, coll. Wang Chong-Rui [王崇瑞], Chen Hui [陈辉]). The new species can be promptly distinguished from all the other Chinese camaenid taxa in genitalia because of the absence of the dart sac apparatus and the flagellum.
The phylogenetic analysis suggested that the new species / genus and the taxa distributed in Central China are possibly close relatives (Fig. 7). For other comments see the genus.
description: Published as part of Wu, Min, Chen, Tian & Shen, Wang, 2024, New camaenid genus and species from Zhejiang, East China (Eupulmonata, Helicoidea), pp. 135-154 in ZooKeys 1202 on pages 135-154, DOI: 10.3897/zookeys.1202.118964