Globotrochus onestera (Mabille, 1887)

Sutcharit, Chirasak, Backeljau, Thierry & Panha, Somsak, 2019, Re-description of the type species of the genera Ganesella Blanford, 1863 and Globotrochus Haas, 1935; with description of a new Ganesella species from Thailand (Eupulmonata, Camaenidae), ZooKeys 870, pp. 51-76 : 51

Globotrochus onestera (Mabille, 1887) Figs 1D , 4 E–G , 6 , 7 G–I , 8

Helix onestera Mabille, 1887a: 3. Mabille 1887b: 89, 90, pl. 2, figs 4, 5. Dautzenberg and Fischer 1908: 184, 185. Haas 1935: 46, 47. Fischer and Dautzenberg 1904: 404.

Ganesella (Globotrochus) onestera : Zilch 1960: 611, fig. 2143. Zilch 1966: 210.

Ganesella onestera : Richardson 1985: 140.

Globotrochus onestera : Schileyko 2003: 1519, fig. 1959. Schileyko 2011: 46. Inkhavilay et al. 2019: 152, fig. 60c.

Diastole simonei Thach & Huber in Thach 2017: 34, 35, figs 418-420. Type locality: Nho Quan District, Ninh Binh Province, North Vietnam. New Synonym.

Type locality.

Tonkin [north Vietnam].

Material examined.

Type material. This species was described on the basis of shells from the Balansa coll. Mabille (1887b: 89, 90, pl. 2, figs 4, 5) re-published the description of the species with an illustration of a shell. The MNHN-Malacologie collection contains two lots with syntypes. The first lot is from the Balansa coll. and consists of two shells with an original label giving the taxon name, collection locality and marked with the word "M. Balansa 1887. Type". One of the two shells is not damaged and its size closely matches the measurements in the original description and the illustration of Mabille (1887b: pl. 2, figs 4, 5). This shell is, therefore, here designated as the lectotype MNHN-IM-2000-32456/1 ( Fig. 4E , height 15.1 mm, width 20.5 mm, 5 whorls). The second shell is broken up into three pieces and becomes the paralectoype MNHN-IM-2000-32456/2 (1 shell). The second lot MNHN-IM-2000-2073 consists of a shell with the marking “Type” on its label. Yet, this lot does not belong to the Balansa collection and was subsequently labeled as " H. onestera J. Mab. var.". Therefore, we exclude this lot from the type series of this nominal species ( ICZN 1999: Art. 72.4.1).

Other material.

VIETNAM: Nho Quan, District, Ninh Binh Province, North Vietnam: holotype of Diastole simonei Thach & Huber, 2017 MNHN-IM-2000-33206 (1 shell; Fig. 4F ). Buc-Kan, Tonkin: NHMUK Kennard coll. (1 shell), MNHN (1 juvenile shell). Haiphong, Tonkin: NHMUK 1893.12.8.21-22 (2 shells), NHMUK Salisbury ex Beddome coll. (2 shells), SMF 27512 (3 shells), SMF 297452 (2 shells), ZMB 47931 (1 shells), NHMW 23331 (1 shell). Nin-Cho, Nga Ba Tha, Tonkin: SMF 297450 (3 shells), NHMW 11734 (2 shells), NHMW 50818 (2 shells), NHMW Rusnov coll. (2 shells). Da-Bac, Tonkin: SMF 297451 (3 shells). Cuc Phuong National Park, Nho Quan District, Ninh Binh Province (20°14'59.0"N, 105°42'52.3"E): CUMZ 5128 ( Fig. 4G ), 5129.

Description.

Shell. Shell medium-sized, dextral, thin and trochoid. Apex acute; embryonic shell smooth with brownish colour. Whorls 5-6, increasing regularly, slightly convex and slightly shouldered near suture; suture wide and shallow. Shell surface smooth or with fine growth lines. Last whorl large, angular with strong keel, beneath slightly convex. Shell monochrome, light brownish and translucent. Aperture semi-ovate; lip slightly expanded and brownish; parietal callus thin. Umbilicus closed; columella small and whitish.

Genitalia. Male genital organ (N = 3) thin (small size and fully function). Atrium (at) short, about as long as penis. Penis (p) short, proximally cylindrical, distally like a short, but wider tube. Penial sheath and penial verge absent. Epiphallus (e) small, as long as penis; flagellum absent. Vas deferens (vd), short, narrow, extending from free oviduct to tip of epiphallus. Penial retractor muscle (pr) relatively thin and long ( Fig. 6A ).

Vagina (v), cylindrical, short, size and shape similar to atrium. Gametolytic duct (gd) long and narrow; distally terminating at gametolytic sac (gs). Free oviduct (fo) relatively long; oviduct widened by curled lobules. Albumen gland (ag) curved lingulate. Hermaphroditic duct (hd) convoluted and located between hermaphrodic gland (hg) ( Fig. 6A ).

Internal walls of vagina with several smooth surfaces of longitudinal pilasters (vp). Vaginal wall itself with strong longitudinal ridges through the vaginal chamber ( Fig. 6B ).

Radula. Teeth arranged in anteriorly pointed, nearly straight rows, each row containing about 79 (39-1-39) teeth. Central tooth symmetric tricuspid, mesocone large with pointed cusp, ectocone very small and located in the middle of tooth. Lateral and marginal teeth undivided. Inner teeth (no. 1-14) asymmetric tricuspid, endocone and ectocone small, and mesocone large with pointed cusp ( Fig. 7G, H ). Outermost teeth tricuspid, endocone small and located close to apex of teeth; mesocone relatively large with curved cusp, and ectocone located at base and cusps sometimes split into two pointed cusps ( Fig. 7H, I ).

Jaw crescent, with anteriorly convex cutting margin. Vertical ribs prominent, variable in number and size ( Fig. 6D ).

Pallial system. Typical sigmurethran; heart (auricle and ventricle) located left of kidney (on right in Fig. 6C ). Pulmonary cavity approximately 5 × longer than wide. Pulmonary vein and venation on lung roof distinct and well developed. Kidney elongated, slender and extending from posterior side of cavity to approximately half of pulmonary cavity. Ureter sigmoidal, closed tube arising from apex of kidney, extending along right side of kidney, recurving adjacent to rectum. Rectal opening adjacent to anus and mantle collar ( Fig. 6C ).

Distribution.

This species is known from the type locality and recent records from Cuc Phuong National Park, Ninh Binh, and Nui Con Vui near Hai Phong, in northern Vietnam ( Schileyko 2011).

Remark.

Live specimens of this species were collected for the first time in 2006 at Cuc Phuong, Vietnam. This is a very humid area with tropical forest patches and limestone karst. The snails were collected on small shrubs, suggesting that it may be an arboreal species.

Recently, Thach (2017) described a new species from Vietnam under the southern Pacific Islands endemic genus Diastole Gude, 1913 (see Schileyko 2002). The species Diastole simonei Thach & Huber, 2017 was described from the same geographical area as Globotrochus onestera , the original description of which did not mention this species. The type specimens of Globotrochus onestera and Diastole simonei are identical in all characters. Hence, we treat Diastole simonei Thach & Huber, 2017 as a junior subjective synonym of Globotrochus onestera .

Figures

Figure 1. A, B Ganesella carinella from Keng-khoy, Saraburi (shell width about 15 mm) A live snail and B snails aestivated under loose tree bark, and with white epiphrams attached on substrate C Ganesella rhombostoma from Klong Had, Srakeo (shell height about 15 mm) D Globotrochus onestera from Cuc Phuong, Vietnam (shell width about 15 mm).

Figure 4. A-C Ganesella halabalah sp. nov. A holotype CUMZ 2608 B paratype CUMZ 2599 from the type locality and C paratype ZMB 53120 from Kelantan, Malaysia D Ganesella perakensis, syntype MNHN-IM- 2000 - 1964. E-G Globotrochus onestera E lectotype MNHN-IM- 2000 - 32456 F holotype of " simonei Thach & Huber, 2017 " MNHN-IM- 2000 - 33206 and G specimen from Vietnam CUMZ 5218 H Globotrochus mellea, holotype RBINS / MT / 525051.

Figure 6. Anatomy of Globotrochus onestera from Cuc Phuong, Vietnam. A general view of genital system B internal structure of vaginal chamber C pallial system and pulmonary cavity and D jaw.

Figure 7. Radula. A-C Ganesella carinella D-F Ganesella rhombostoma and G-I Globotrochus onestera A, D, G central tooth with the first to the second lateral teeth B, E, H lateral teeth with the tricuspid marginal teeth transition C, F, I outermost marginal teeth. Numbers indicate order of lateral and marginal teeth. Central tooth indicated by ' C'.

Figure 8. Geographic distribution of Ganesella spp. and Globotrochus spp.