Land snail diversity in central China: revision of Laeocathaica Moellendorff, 1899 (Gastropoda, Camaenidae), with descriptions of seven new species
Author
Wu, Min
https://orcid.org/0000-0002-5434-5544
School of Life Sciences, Nanjing University, Nanjing 210023, China
minwu1969@aliyun.com
Author
Shen, Wang
School of Life Sciences, Nanjing University, Nanjing 210023, China
Author
Chen, Zhong-Guang
https://orcid.org/0000-0003-2689-3321
Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecology, Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang 330031, China
text
ZooKeys
2023
2023-03-20
1154
49
147
http://dx.doi.org/10.3897/zookeys.1154.86237
journal article
http://dx.doi.org/10.3897/zookeys.1154.86237
1313-2970-1154-49
4E410C2ACC03438F8AC7C5370819DE6C
E4F41DD1A11059DAB4A979F00E85D50F
Genus
Laeocathaica
Moellendorff
, 1899
Laeocathaica
Moellendorff
, 1899: 86;
Richardson 1983
: 77;
Schileyko 2004
: 1686.
Type species.
Helix (Plectotropis) christinae
H. Adams, 1870 (by original designation).
Description.
Shell sinistral, strongly depressed to broadly conic, moderately solid, of 5-10.5 almost flat whorls. Last whorl abruptly descending in front, angulated to strongly keeled; rarely rounded. Coloration consists of whitish, corneous, or chestnut background and mostly with one or two dark sub-peripheral bands; besides, usually there are several fulvous, diffuse radial streaks. Protoconch usually with fine radial threads and/or fine granules that each is formed by a low hump deposited in a shallow socket. Sculpture of teleoconch whorls varying from fine, silky radial striation to rather strong ribbing; on basal surface below keel or angle this sculpture becomes much weaker. Aperture rounded to peach-shaped, oblique, margins usually more or less reflexed. Within aperture a ring-like thickening present. Apertural teeth absent or with one tuberculiform basal tooth and sometimes with another one on palatal wall. During postembryogenesis several sets of teeth, different from those developed at adult stage in shape and/or number, present and remained to adult stage. Umbilicus moderate to very wide, ratio of umbilicus diameter to maximum diameter 0.21-0.50. Height 3.5-14 mm, maximum diameter 10.0-29.5 mm.
On left and right side of mantle edge, no leaf-shaped appendage present. Head wart between ommatophores present, weak, or developed. Jaw arcuate, with 3-8 more or less projecting ribs.
Slender vas deferens entering epiphallus at penial retractor muscle insertion. Penis generally clavate, rarely subcylindrical. Penis internally divided into three regions: the proximal part with narrow or thick longitudinal pilasters, among which one pair or two pairs of adjacent pilasters fuse into one Y-shaped fork or two Y-shaped forks (not in
Laeocathaica christinae
,
L. phaeomphala
, and
L. qingchuanensis
Wu, sp. nov.). The median part, composed of fine pilasters that weave into network or covered by isolated tongue-like/diamond-like granules erecting on penial wall. The distal part, near epiphallic opening, with mini-pilasters crowded and forming several short and thick pilasters. Epiphallic papilla absent. Penial sheath always present, surrounding proximal penis. Dart sac always present. Accessory sac presents at ventral dart sac, internally solid or narrowly empty. Mucous glands 2-12, each simply or complicatedly branched, entering accessory sac separately before being united into a common duct inside wall of accessory sac. Proximal section of dart sac with 0-2 PAS that if present, each has a tiny opening leading to dart chamber. Vagina between atrium and dart sac elongated only in a few species. Bursa copulatrix duct subcylindrical throughout (modified from
Schileyko 2004
).
Distribution.
China: S Gansu, W Hubei, W Shaanxi, Chongqing, Sichuan.
Remarks.
Laeocathaica
species are granulate on the protoconch, which is smooth in actual observation due to erosion or weathering. In the original description of
Laeocathaica filippina
, Heude (1882) first mentioned the irregular white radiate stripes (1882), which were particularly noted by
Moellendorff
(1899)
as "die stets vorhandenen Jugendlippen (the ever-present juvenile lips)" that joined the definition of
Laeocathaica
.
Moellendorff
(1899)
also noticed in
Euhadra haplozona
Moellendorff
, 1899 and
Euhadra eris
Moellendorff
, 1899 such "ever-present juvenile lips" exist. The juvenile lips, which have remained on the mature shell, may be frequent and weak such as those of
L. minwui
Pall-Gergely
, 2022 (Fig.
11A
) and many other species, or sparse and strong as those of
Laeocathaica dityla
(Fig.
13D
) and
L. parapolytyla
Wu, sp. nov. (Fig.
25
). Regarding the genital organs, the Y-shaped forks present on the proximal part of inner wall of the penis were observed exclusively in most anatomically studied
Laeocathaica
species among the Chinese dart-sac-bearing camaenids.