Pila gracilis (Lea, 1856)

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 gracilis (Lea, 1856) Fig. 5A

Ampullaria gracilis Lea, 1856: 110. Type locality: “Siam”.

Pila gracilis : Brandt 1974: 51-52, pl. 6, fig. 84.

Material examined.

ZRC.MOL.015669, ZRC.MOL.015670, ZRC.MOL.015690, ZRC.MOL.015673, ZRC.MOL.015677.

Distribution and habitat.

Tonle Sap River, Tonle Sap Lake open areas, and small ponds and paddy fields in the provinces surrounding the Lake (locality no. 4, 7, 9, 10, 24 and 28).

Remarks.

The first record of this species from Cambodia was from the Kampong Svay District in Kampong Thom Province ( Crosse and Fischer 1876), which is slightly to the north of the Tonle Sap basin. This species is widely distributed in southern Thailand to central Malay peninsula, very rare in eastern Thailand, and also known from southern Vietnam ( Brandt 1974; Ng et al. in press). Pila gracilis seemed to be rare in the eastern Thai provinces that border Cambodia ( Ng et al. in press) but appears to be common in the Tonle Sap basin. Although Pila gracilis was not previously recorded as being harvested from the Tonle Sap Lake ( Ngor et al. 2016, 2018d), we recorded Pila gracilis being sold together with Pila pesmei (Morlet, 1889) and Pila virescens (Deshayes, 1824) at one landing site in Kampong Chhnang Province, and collected Pila gracilis and Pila virescens from within the Lake.

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.