Amphidromus (Amphidromus) syndromoideus Inkhavilay & Sutcharit & Panha 2017, sp. nov.
Creators: name: Inkhavilay, Khamla
name: Sutcharit, Chirasak
name: Panha, Somsak
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Camaenidae
Amphidromus
Amphidromus syndromoideus

description: Amphidromus (Amphidromus) syndromoideus Inkhavilay & Panha sp. nov.
urn:lsid:zoobank.org:act: 26B7BD0E-55D1-494B-B057-6D7986EB36DA
Figs 1, 2D, 3D, 4 J–K, 6C–D, 7D−F; Table 1
Diagnosis
The new species differs from all other known Amphidromus (Syndromus) species in having a long epiphallus and flagellum and very long appendix, both being unique characters of the nominotypical subgenus (Solem 1983; Sutcharit & Panha 2006). The new species differs from A. roseolabiatus in having a small and thin shell, inconspicuous greenish radial streaks and about two times longer appendix. In contrast, A. roseolabiatus has a larger solid shell, conspicuously greenish radial streaks in fresh specimens, sometimes with a single brownish spiral band below the periphery, purplish-pink apertural lip, and a short appendix.
Etymology
The specific epithet ‘ syndromoideus ’ is from ‘ syndromus ’, an Amphidromus subgeneric name, and the suffix ‘– oideus ’, meaning ‘like or resembling’. This name refers to the resemblance in shell morphology of the new species with members of the subgenus Syndromus.
Type material
Holotype
LAOS: dextral, shell height 28.2 mm, shell width 13.4 mm, with 6½ whorls (CUMZ 7019, Figs 2D, 3D, 4J, 6 C–D, 7D−F).
Paratypes
LAOS: 22D + 9 S shells (Fig. 4 K, Table, CUMZ 7020 (1); 1 S specimen, in ethanol (CUMZ 7021); 1D + 1 S shells (NHMUK); 1D + 1 S shells (SMF).
Type locality
LAOS: Tam Narng Ann (cave), Thakhek District, Khammouan, 17°26′39.2″ N, 104°56′54.8″ E, 163 m amsl.
Description
Shell chirally dimorphic, thin, rather small, elongate conical and glossy. Spire conical; apex acute, brownish and without black spot on tip. Whorls 5 to 6 weakly convex; suture depressed; last whorl rounded. Periostracum thin and transparent. Last whorl with narrow white subsutural band and shell color uniform yellowish with green radial streaks on last whorl (pale to inconspicuous in older whorls and empty shells); varix absent. Parietal callus thin and transparent. Aperture wide ovate; peristome weakly expanded; lip whitish or transparent. Columella straight, thickened and white. Umbilicus narrowly opened.
Radula
Each row contains about 105 (54-(3-5)-1-(3-5)-50) teeth. Central tooth small, unicuspid, with spatulotruncated cusp. Lateral teeth bicuspid; endocone cylindrical, with wide notch; ectocone large, with truncated cusp. Marginal teeth tricuspid, starting around tooth number 3 to 5; endocone small, with sharp cusp; mesocone large, with truncated cusp; ectocone smallest. Outermost teeth with curved and pointed cusp of endocone; mesocone large, with curved cusp; ectocone of triangular shape, with pointed cusp (Fig. 7 D−F).
Genital organs
Atrium (at) rather short (n = 10). Penis (p) short and conic-shaped. Epiphallus (e) long, slender and two times longer than penis. Flagellum (fl) short, about half length of epiphallus and terminated in folded coil. Appendix very long, small tube extends from folded coil of flagellum, about three times as long as epiphallus. Penial retractor muscle (pr) short, thickened and inserted distally on penis. Vas deferens (vd) narrow tube connecting epiphallus and free oviduct (Fig. 6C).
Internal penial wall, proximal to genital orifice, corrugated into series of thick penial pilasters (pp) form fringe; distal to genital orifice smooth around penial verge. Penial verge (pv) small, conical and smoothsurfaced (Fig. 6D).
Vagina cylindrical, about four times as long as penis. Gametolytic duct very long, proximal to genital orifice large, coiled; distal to genital orifice tapering to small tube and connected to ovate gametolytic sac. Oviduct and albumin gland very small (Fig. 6C).
Internally, vaginal wall shows longitudinal vaginal pilasters (vp); proximal to genital orifice with smooth, thickened and continuous ridges, and distally pilasters thinner, with smooth ridges (Fig. 6D).
Distribution
This new species is currently known from the type locality only, a dry evergreen forest with limestone outcrops in the central part of Laos at Thakhek District, Khammouan Province.
Remarks
Two living snails were found during the aestivation period in a small tree hole a height of 5 m (Fig. 3D).
description: Published as part of Inkhavilay, Khamla, Sutcharit, Chirasak & Panha, Somsak, 2017, Taxonomic review of the tree snail genus Amphidromus Albers, 1850 (Pulmonata: Camaenidae) in Laos, with the description of two new species, pp. 1-40 in European Journal of Taxonomy 330 on pages 16-17, DOI: 10.5852/ejt.2017.330, http://zenodo.org/record/3829744