Dyakia sp.

Sutcharit, Chirasak, Thach, Phanara, Chhuoy, Samol, Ngor, Peng Bun, Jeratthitikul, Ekgachai, Siriwut, Warut, Srisonchai, Ruttapon, Ng, Ting Hui, Pholyotha, Arthit, Jirapatrasilp, Parin & Panha, Somsak, 2020, Annotated checklist of the land snail fauna from southern Cambodia (Mollusca, Gastropoda), ZooKeys 948, pp. 1-46 : 1

Dyakia sp. Fig. 9D

Material examined.

Locality no. 15: CUMZ-CM155 (5 shells), CUMZ-CM156 (4 shells), CUMZ-CM157 (1 shell; Fig. 9D ), CUMZ-CM158 (3 specimens in ethanol). The snails were found to live on tree trunks and leaves.

Remarks.

The large sinistral helicoid shell discriminates this species from most other species known in this region. This species can be distinguished from Bertia cambojiensis (Reeve, 1861) by having a brownish shell, with spirally undulated surfaces, while B. cambojiensis has a smooth surface (see Sutcharit et al. 2019b for further comparison).

The specimens from the Popokvil Waterfall (locality no. 15) located on the plateau of Preah Monivong Bokor National Park may be young individuals, as their shell size is relatively small compared to those of other congeners recorded from peninsular Thailand. It differs from D. salangana (Martens, 1883) and D. retrorsa (Gould, 1843) by having a dark brown shell, with wide angle of peripheral keels. In contrast, D. retrorsa tends to have sharp peripheral keel, D. salangana has round periphery and usually with brownish peripheral band, and both species are pale brownish in shell colour ( BEDO 2017).

Figures

Figure 9. A Allopeas gracile (Hutton, 1834) B Lissachatina fulica (Bowdich, 1822) C Haploptychius sp. D Dyakia sp. and E, F Quantula weinkauffiana (Crosse & Fischer, 1863) with E angular last whorl and F rounded last whorl.