Ganesella carinella ( Moellendorff , 1902)

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

Ganesella carinella ( Moellendorff, 1902) Figs 1A, B , 2 F–H , 3A, B , 5 A–D , 7 A–C , 8

Eulota (Ganesella) hariola carinella Möllendorff, 1902: 158, 159. Zilch 1966: 202.

Ganesella capitium [non Benson 1848]: Pilsbry 1895: 170, 360, pl. 55, fig. 18. Blanford 1903: 278. Gude 1914: 196, 197. Zilch 1960: 610, fig. 2140. Zilch 1966: 202. Richardson 1985: 132, 133. Schileyko 2003: fig. 1958.

Type locality.

Siam, Muoklek and Kanburi [Thailand: Muaklek District, Saraburi Province and Kanchanaburi Province].

Material examined.

Type specimens. Lectotype SMF 27534a ( Fig. 2F , height 14.8 mm, width 18.5 mm) and paralectotype SMF 27534b (1 shell; Fig. 2G , height 17.6 mm, width 18.2 mm) from Siam [Thailand].

Additional material.

CAMBODIA: Cambodia: NHMUK Cuming coll. ex Mouhot (2 shells). THAILAND: Siam: NHMUK 1902.9.17.30-31 (2 shells). Tam Barijinda, Chom Thong District, Chiangmai Province: CUMZ 4153, 4193, 4165 ( Fig. 3B ), 5123. Wat Tham Rakung, Sri Samrong District, Sukhothai Province: CUMZ 4937. Tam Lom-Tam Wang, Sri Samrong District, Sukhothai Province: CUMZ 4938. Tam Pha Thaphol, Nern Maprang District, Phitsanuloke Province: CUMZ 4195, 5127. Tam Wang Daeng, Nern Maprang District, Phitsanuloke Province: CUMZ 4932, 4939, 5113, 5126. Wat Chuek Charoentham, Ban Rai District, Uthaithani Province: CUMZ 4935. Wat Sri Uthumporn, Muang District, Nakhonsawan Province: CUMZ 4940. Tam Phet-Tam Thong, Takhi District, Nakhonsawan Province: CUMZ 4173, 4943, 5121, 5133 ( Fig. 2H ). Tam Poon Sawan, Srithep District, Phetchabun Province: CUMZ 4284. Tam Sombat Chomphol, Lomsak District, Phetchabun Province: CUMZ 4934, 5115, 5125. Khao Samokorn, Tha Wung District, Lopburi Province: CUMZ, 4218, 4279, 4282 ( Fig. 3A ), 4933. Wat Bandai Samsaen, Banmee District, Lopburi Province: CUMZ 4280. Tam Santisuk, Kok Samrong District, Lopburi Province: CUMZ 4931. Tam Tam-bon, Chaibadan District, Lopburi Province: CUMZ 5116. Muak Lek Waterfall, Muak Lek District, Saraburi Province: CUMZ 4186, 4172, 4941. Tam Dao Khaokaeo, Muak Lek District, Saraburi Province: CUMZ 4197. Tam Singha Ratde-cho, Kaeng Khoi District, Saraburi Province: CUMZ 4164, 4178, 5122. Tam Sriwilai, Chaloem Phrakiat District, Saraburi Province: CUMZ 4187, 4930. Wat Thep Pitak, Pakchong District, Nakhon Ratchasrima Province: CUMZ 4199. Wang Takrai Waterfall, Muang District, Nakhon Nayok Province: CUMZ 4942. Wat Khao Chakan, Khao Chakan District, Srakaeo Province: CUMZ 4159, 4182, 4213, 5114. Ta Praya District, Srakaeo Province: CUMZ 4283. Tam Phet Phothong, Klonghad District, Srakaeo Province: CUMZ 5120. Tam Kaeo Sawanbandan, Pong Namron District, Chanthaburi Province: CUMZ 4165.

Description.

Shell. Shell small, dextral, thin and depressed 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 convex. Shell brownish and translucent, with wide, whitish-opaque, irregular spiral band on upper and lower side. Aperture ovate; lip slightly expanded and whitish; parietal callus transparent. Umbilicus rimate with small hole; columella whitish and expanded overhanging umbilicus.

Genital organs. Atrium (at) short (N = 10) and proximally with blackish tissues. Penis (p) cylindrical, about as long as the vagina; proximally blackish; distally slightly enlarged at penial verge. Epiphallus (e) and flagellum (fl) very short, approximately one-third of penis length. Vas deferens (vd) long and narrow, extends from free oviduct and terminates at distal epiphallus. Penial retractor muscle (pr) long and thin. Flagellum short, as long as or longer than epiphallus ( Fig. 5A ).

Penial verge (pv) small, conical, and with smooth surface. Penial wall ribbed, forming a series of swollen longitudinal pilasters (pp); middle wall with very thin pilasters. Pilasters swollen in the distal portion of penial chamber ( Fig. 5B ).

Vagina (v) long, cylindrical and proximally with blackish tissues. Gametolytic duct (gd) short; proximally wider; distally tapering to small tube and terminated with gametolytic sac (gc). Free oviduct (fo) short; oviduct (ov) enlarged with curled lobules. Albumen gland (ag) curved ligulate. Hermaphroditic duct (hd) convoluted and connected to hermaphrodic gland (hg) ( Fig. 5A ).

Internal wall of vagina with smooth, longitudinal, vaginal pilasters (vp); with slightly deep crenulated ridges throughout vaginal chamber ( Fig. 5B ).

Radula. Teeth arranged in nearly straight rows, each row containing 74 (37-(4-6)-1-(4-6)-36) teeth. Central tooth monocuspid with spatulate and truncate cusp. Lateral teeth larger than central tooth; teeth no. 1-3 monocuspid, no. 4-6 bicuspid, endocone spatulate and ectocone very small with pointed cusp ( Fig. 7A, B ). Marginal teeth start from teeth no. 6-7. Inner marginal teeth tricuspid, endocone and ectocone very small with pointed cusp and mesocone large and spatulate. Outermost teeth (near radula edge) tricuspid, endocone and ectocone with two or more pointed cusps, and mesocone large with curved cusp ( Fig. 7B, C ).

Jaw crescent, with anterior convex cutting margin. Vertical ribs prominent, and variable in number and size ( Fig. 5D ).

Pallial system. Typical sigmurethran; heart (au and ve) located left of kidney (on right in Fig. 5C ). Pulmonary cavity approximately 5 × longer than wide. Pulmonary vein (puv) and venation on lung roof (l) distinct and well developed. Kidney (k) long, slender and extending from posterior side to approximately the middle of pulmonary cavity. Ureter (ur) is a sigmoid, closed tube arising from apex of kidney, extending along right side of kidney, recurving near rectum (r). Rectal opening adjacent to anus (a) and pneumostome (pn) ( Fig. 5C ).

Distribution.

Ganesella carinella is widely distributed in Thailand: northern area in Chiangmai, Phitsanuloke; northeastern area in Loei, Phetchaboon, Nakhonratchasrima; central area in Saraburi, Lopburi; eastern area in Srakeow, Chanthaburi; western area in Kanchanaburi.

Remarks.

Hitherto, Ganesella carinella was regarded as a junior synonym of G. capitium . However, after Budha et al. (2012) described the genital apparatus of conchologically typical G. capitium , it became clear that G. carinella differs from the type species not only by having a more depressed shell with a strong peripheral keel but also by its longer penis and epiphallus, and its shorter vagina. In contrast, G. capitium has a more elevated trochoid shell, an angular last whorl, a shorter penis and epiphallus, and a longer vagina.

Ganesella carinella shows considerable variation in shell shape and colour. For example, specimens from Lopburi ( Fig. 3A ) tend to be paler and have a more descending aperture than specimens from Saraburi. Specimens from Chiangmai ( Fig. 3B ) tend to have more whitish spots on their shell than specimens from Lopburi and Saraburi. Yet, this conchological variation is not matched by consistent genital differences. Therefore, we conclude that the shell variation within this widely-distributed species only involves intraspecific polymorphism.

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 2. A, B Ganesella capitium A lectotype UMZC I. 102385 / 1 and B paralectotype UMZC I. 102385 / 2 - 3 C-E Ganesella hariola C lectotype UMZC I. 104370 / 1 D paralectotype UMZC I. 104370 / 2 - 4 and E shell from Popa Mountain, Myanmar CUMZ 5134 F-H Ganesella carinella F lectotype SMF 27534 a G paralectotype SMF 27534 b and H shell from Takhli, Nakhonsawan CUMZ 5133.

Figure 3. A, B Ganesella carinella A shell from Lopburi CUMZ 4282 and B shell from Tam Brichinda, Chiangmai CUMZ 4165 C-I Ganesella rhombostoma C lectotype NHMUK 20130215 / 1 D paralectotype NHMUK 20130215 / 2 - 3 E shell of " harryleei Thach, 2017 " from Cambodia FMNH 381985 F shell from Klonghad, Srakeo CUMZ 5132 G shell from Chachoengsao CUMZ 5130 H shell from Sirisophon, Cambodia CUMZ 5131 and I shell from Srakaeo CUMZ 4286.

Figure 5. A-D Ganesella carinella from Saraburi A general view of genital system B internal structure of penis and vagina C pallial system and pulmonary cavity and D jaw E-G Ganesella rhombostoma from Srakaeo E general view of genital system F internal structure of penis and vagina and G 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.