Amphidromus (Amphidromus) laosianus Bavay, 1898

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, European Journal of Taxonomy 330, pp. 1-40 : 10

Amphidromus (Amphidromus) laosianus Bavay, 1898

Figs 1 , 4G

Amphidromus laosianus Bavay, 1898: 15 , 16, pl. 2, fig. 1, 1a. Type locality: Khône, sur les bords du Mékong [on the banks of the Mekong River, Khone, Champasak, Laos].

Amphidromus laosianus var. albocaerulescens Bavay, 1898: 16 , pl. 2, fig. 2, 2a. Type locality: Khône, sur les bords du Mékong [on the banks of the Mekong River, Khone, Champasak, Laos].

Amphidromus laosianus – Pilsbry 1900: 183, 184, pl. 62, figs 60–61. — Laidlaw & Solem 1961: 526, 634.

Amphidromus laosianus var. albocaerulescens – Pilsbry 1900: 184, pl. 62, figs 62–63. — Laidlaw & Solem 1961: 526, 598.

Material examined

LAOS: 1D + 1S shells ( Fig. 4G ), Khone District, Champasak, South Laos ( RMNH 101049); 1D + 2S shells, W.J.M. Maassen collection; 2D + 2D juveniles, Khone, South Laos, ZMB, Lehmann collection.

Remarks

Currently known only from the type locality. The unique shell characters are chirally dimorphic, conical to elongate conical; whorls weakly convex, with white subsutural band. Shell color with yellowishbrown or brownish radial streaks on pinkish to whitish ground color; dark varix present. Aperture elongated; peristome thickened, expanded and reflected; lip folded and pinkish. Parietal callus pinkish and thickened; columella pinkish and straight; umbilicus imperforated.

Laidlaw & Solem (1961) mentioned that this species is similar to the A. atricallosus leucoxanthus variety “ laidlawi ” ( Solem 1965: pl. 1, fig. 3; Sutcharit & Panha 2006: fig. 4d–e). However, it differs in having a slender shell and pinkish peristome, parietal callus and inside of the aperture, while “ var. laidlawi ” has a white lip, parietal callus and inside aperture, and more depressed suture. Furthermore, A. cambojiensis (Reeve, 1860) can be distinguished from this species by having a very large and thickened shell, thickened and white parietal callus and lip, and purplish inside aperture (see Sutcharit et al. 2015).

Figures

Fig. 1. Distribution map of Amphidromus spp. in Laos recognized in this study.

Fig. 4. Shells of Amphidromus (Amphidromus) spp. A−F. Amphidromus roseolabiatus Fulton, 1896. A–B. Typical form from Ban Phavong, Khammouan, Laos (CUMZ 7011). C–D. Form with white lip from Nam Turn Bridge, Bolikhamxay, Laos (CUMZ 7006). E–F. Form with white lip from Tam Mung Korn, Bolikhamxay, Laos (CUMZ 7004). G. Amphidromus laosianus Bavay, 1898 from Khone, Champasak, Laos (RMNH 101049). H. Amphidromus protania Lehmann & Maassen, 2004, holotype (RMNH 98143). I. Amphidromus givenchyi Geret, 1912 from Thad Lor Waterfall, Salavan, Laos (CUMZ 7015). J–K. Amphidromus syndromoideus sp. nov. from the type locality. J. Holotype (CUMZ 7019). K. Paratype (CUMZ 7020).