Pila pesmei (Morlet, 1889)

Ng, Ting Hui, Jeratthitikul, Ekgachai, Sutcharit, Chirasak, Chhuoy, Samol, Pin, Kakada, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Hogan, Zeb S. & Ngor, Peng Bun, 2020, Annotated checklist of freshwater molluscs from the largest freshwater lake in Southeast Asia, ZooKeys 958, pp. 107-141 : 107

Pila pesmei (Morlet, 1889) Fig. 5B

Ampullaria pesmei Morlet, 1899: 185, pl. 8, fig. 2. Type locality: "Phnom-Penh (Cambodge)".

Pila pesmei : Brandt 1974: 51, pl. 5, figs 70, 71.

Material examined.

ZRC.MOL.015671.

Distribution and habitat.

Tonle Sap open area (locality no. 38).

Remarks.

Although Pila pesmei is widely distributed in Eastern and Northeastern Thailand ( Ng et al. in press), the species does not appear to be as widespread as Pila gracilis in the Tonle Sap basin, especially during the dry season when our surveys were conducted. It is also uncertain if the species is still extant at its type locality of Phnom Penh. Pila pesmei is harvested in abundance from the Tonle Sap Lake in the rainy season, with more than 380 tonnes recorded at five commercial landing sites in Kampong Chhnang Province within one year (as Pila ampullacea (Linneaus, 1758) in Ngor et al. 2016, 2018d). Pila pesmei may be confused with Pila gracilis owing to morphological similarity among some populations ( Ng et al. in press), and further extensive examination of both species in Cambodia would be necessary to resolve the true distribution of both species in the country. The Pila pesmei morph from Tonle Sap Lake have relatively flat spires, compared to those in Thailand ( Ng et al. in press), and appear to also be found in Southern Vietnam (as Pila erythrochila (Dautzenberg & Fischer, 1905) in Ng et al. 2019).

Figures

Figure 5. Freshwater gastropods of the Tonle Sap basin, Cambodia A Pila gracilis B Pila pesmei C Pila virescens D Pomacea maculata E Filopaludina martensi cambodjensis F Idiopoma umbilicata G Mekongia rattei H Trochotaia trochoides I Bithynia siamensis goniomphalus J Wattebledia siamensis K Anentome cambojiensis L Anentome helena M Sulcospira housei N Melanoides tuberculata O Indoplanorbis exustus and P Radix rubiginosa. Scale bars: 10 mm, unless stated otherwise. Photographs by TH Ng.