Macrochlamys kelantanensis Möllendorff, 1902

Pholyotha, Arthit, Sutcharit, Chirasak & Panha, Somsak, 2018, The land snail genus Macrochlamys Gray, 1847 from Thailand, with descriptions of five new species (Pulmonata: Ariophantidae), Raffles Bulletin of Zoology 66, pp. 763-781 : 775-778

Macrochlamys kelantanensis Möllendorff, 1902

( Figs. 2F , 8B–D , 9C, D , 10G–I )

Macrochlamys hardwickei kelantanensis Möllendorff, 1902a: 137 (type locality: Kelantan, Ostküste der Halbinsel Malacca [Kelantan, east coast of Peninsula Malaysia]) – Maassen, 2001: 110.

Material examined. Holotype ( SMF 227098 ), one paratype shell ( SMF 227099 ), Kelantan, east coast of Peninsula Malaysia. Non type material: THAILAND. five shells ( CUMZ 7120 ), 16 specimens ( CUMZ 7121 ), Mae Chan District , Chiang Rai Province, 20° 08′38.7″N 99° 51′21.4″E; 32 specimens ( CUMZ 7122 ), Nong Han , San Sai District , Chiang Mai Province, 18° 53′23.7″N 98° 59′54.7″E; two specimens ( CUMZ 7123 ) Mae Sot District , Tak Province, 16° 43′26.9″N 98° 35′06.0″E; one shell ( CUMZ 7124 ), 10 specimens ( CUMZ 7125 ), Lam Kaen , Phang-Nga Province , 8° 35′48.5″N 98° 15′22.4″E; six specimens ( CUMZ 7126 ), Koh Chang District , Trat Province, 12° 04′36.8″N 102° 22′02.6″E. MALAYSIA: 15 specimens ( CUMZ 7127 ), Bukit Bunga , Kampung Jakar , Ayer Lanas , Kelantan, 5° 49′8.8″N 101° 54′40.4″E; one specimen ( CUMZ 7128 ), Gunung Reng Batu Melintang , Jeli , Kelantan, 5° 42′54.1″N 101° 44′43.3″E; one shell ( CUMZ 7132 ), 46 specimens ( CUMZ 7129 ), Jalan Bunga , Merbok , Kedah, 5° 43′27.7″N 100° 23′22.3″E; one shell ( Fig. 8C ) ( CUMZ 7130 ), 13 specimens ( CUMZ 7131 ), Kampung Seberang Pekan , Baling , Kedah, 5° 41′13.4″N 100° 54′54.2″E.

Description. Shell medium to large ( Fig. 8B–D ; shell height up to 13.0 mm; shell width up to 24.0 mm), dextral, spire depressed to low-conical, thin, translucent, and pale brown in colour. Shell surface nearly smooth with very thin growth lines. Embryonic shell surface smooth, with about 2½ whorls. Whorls 5–6, regularly increasing. Suture impressed. Spire depressed conic to low conical. Apex raised with a spire angle of about 134–142°. Last whorl large with wellrounded periphery. Aperture crescent shape, open obliquely with simple lip. Columellar margin slightly reflected near umbilicus. Umbilicus narrowly open and deep.

Genital organs. Atrium (at) very short. Penis (p) short and cylindrical-shaped. Epiphallus (e) short, slightly smaller than penis diameter, about four times longer than penis. Epiphallic caecum (ec) somewhat enlarged, thick, almost same diameter as penis and coiled about two circles. Penial retractor muscle thin and long. Flagellum (fl) long, cylindrical-shaped, about same length as epiphallus. Vas deference (vd) a long tube between distal end of epiphallus and free oviduct ( Fig. 9C ).

Inner wall of penis supported with very small and irregular penial pilasters (pp). Penial verge (pv) small, cylindrical and located at distal end of penis ( Fig. 9D ).

Vagina (v) short about same length as penis and cylindricalshaped. Dart apparatus (da) very large, long and cylindrical, located at proximal end of vagina. Gametolytic sac (gs) bulbous; gametolytic duct (gd) long, cylindrical and slightly swollen near vagina. Free oviduct (fo) very short, triangular shape and entirely encircled with thick tissues. Oviduct (ov) large lobules; prostate gland (pg) runs alongside oviduct ( Fig. 9C ).

Radula. Radula morphology very similar to M. aurantia new species. Each row contains about 111 teeth with formula (55- (17-16)-1-(15-16)-55). Central tooth symmetrical tricuspid; mesocone large with dull cusp. Lateral teeth asymmetrical tricuspid with very small endocone. Marginal teeth with elongate bicuspid start around tooth number 15 to 17 ( Fig. 10G–I ).

External features. Animal with reticulated skin. Foot and body pale yellowish-grey, slightly darker on dorsal side. Head and tentacles darker grey. Caudal foss (cf) long and narrow, caudal horn (ch) raised, pale brownish colour. Mantle edge (shell lobes and dorsal lobes) well developed, dull brownish in colour ( Fig. 2F ). The snails secrete yellowish slime when disturbed.

Remarks. This species was originally nominated as a subspecies of M. hardwickei Godwin-Austen, 1883 from Lower Bengal, Sylhet and Western Assam ( Möllendorff, 1902a). It is here raised to full species level. It differs from M. hardwickei sensu stricto by its larger shell, the cylindrically shaped penis, and enlarged and short cylindrical appearance of the free oviduct versus a smaller shell, enlarged and triangular-shaped penis, and extremely long free oviduct of M. hardwickei (see Godwin-Austen, 1883: 105–107, pl. 23, figs, 1–4; pl. 28, fig. 1). Macrochlamys malaccana from Peninsular Malaysia has a relatively smaller shell that bears a distinct dark brown spiral line at the suture (see Foon et al., 2017). Unfortunately, genitalia data of M. malaccana is not available for comparison.

Macrochlamys kelantanensis is usually ground dwelling and is often associated with anthropogenic habitats, such as plantations, fruit orchards, gardens or parks. This could explain their wide dispersal and it is believed to have been accidentally introduced through horticultural and agricultural trade activities.

Figures

Fig. 2. Living snails of Macrochlamys spp. from Thailand. A, Macrochlamys aurantia new species, paratype (CUMZ 7103), Thong Pha Phum, Kanchanaburi, shell width about 15 mm; B, M. coleus new species, paratype (CUMZ 7106), Sai Yok, Kanchanaburi, shell width about 15 mm; C,M. caverna new species, paratype (CUMZ 7109), Tha Wung, Lopburi, shell width about 17 mm; D, M. lemma new species, paratype (CUMZ 7116), Ban Mi, Lopburi, shell width about 15 mm; E, M. tanymentula new species, paratype (CUMZ 7119), Thong Pha Phum, Kanchanaburi, shell width about 10 mm; F, M. kelantanensis (CUMZ 7125), Lam Kaen, Phang-Nga, shell width about 20 mm.

Fig. 8. Shells of Macrochlamys brunnea Möllendorff, 1902 (A), and M. kelantanensis Möllendorff, 1902 (B–D). A, Macrochlamys brunnea holotype (SMF 227090/1); B, M. kelantanensis holotype (SMF 227098); C, shell from Kedah, Malaysia (CUMZ 7130); D, shell from Chiang Rai, Thailand (CUMZ 7120).

Fig. 9. Genitalia of Macrochlamys tanymentula new species (A, B), and M. kelantanensis (C, D). A, B, Macrochlamys tanymentula paratype (CUMZ 7119): A, whole reproductive system; B, internal structure of penis with penial verge. C, D, Macrochlamys kelantanensis (CUMZ 7125): C, whole reproductive system; D, internal structure of penis with penial verge. Abbreviations: at, atrium; da, dart apparatus; drm, dart retractor muscle; e, epiphallus; ec, epiphallic caecum; fl, flagellum; fo, free oviduct; gd, gametolytic duct; gs, gametolytic sac; hf, head filament; ov, oviduct; p, penis; pc, penial caecum; pg, prostate gland; pp, penial pilaster; prm, penial retractor muscle; pv, penial verge; ss, sperm sac; tf, tail filament; v, vagina and vd, vas deferens. Arrow indicates position of the penial verge.

Fig. 10. SEM images of the radula of Macrochlamys lemma new species (A–C) (paratype; CUMZ 7116), M. tanymentula new species (D–F) (paratype; CUMZ 7119), and M. kelantanensis Möllendorff, 1902 (G–I) (CUMZ 7125). Central tooth (indicated by ‘C’) with lateral teeth (A, D, G); lateral teeth with tricuspid marginal teeth transition (B, E, H); bicuspid marginal teeth (C, F, I).