Pila occidentalis ( Mousson, 1888 )

Rapalai, Boikhutso Lerato, 2024, An annotated checklist of molluscs recorded from Botswana, Indago: Investigating nature and humanity in Africa 41, pp. 15-44 : 21-22

15. Pila occidentalis ( Mousson, 1888)

Distribution and year: “Nausche or Nausib” (Nossob) River, Bokspits N/A ( Connolly 1912; 1939); Kwando

River, Lizauli [SMWN75897] 1986 ( Brown et al. 1992); western Chobe River at Linyanti channel [SMWN76304] 1986 ( Brown et al. 1992); Boro River channel opposite Nxaraga Lagoon [ETD4280] 1984 ( Brown et al. 1992); Thamalakane River opposite Okavango River Lodge near Maun [ETD4279] 1984 ( Brown et al. 1992); Upper panhandle, Okavango Delta 2000 ( Appleton et al. 2003); Guma Lagoon, Okavango Delta 2000 ( Appleton et al. 2003); Xugana, Okavango Delta [USNM755123, 755124] 1975 ( GBIF 2023 b); “ Okavango Marshes” (Okavango Delta) ( Connolly 1912; 1939); Okavango Delta 1999 ( Jansen van Rensburg 2001), 2018, 2020, 2021, 2022 ( GBIF 2023 b); Lake Ngami 1970 (NMSA 2023); Boteti River channel opposite Nxaraga Lagoon; Moremi Game Reserve, approx. 65 km NW of Maun [NHMR993000187266] 2006 ( GBIF 2023 b); Thamalakane River, Maun 1930 (NMSA 2023); Shorobe 1930 (NMSA 2023).

Geographic range: Angola, Botswana, Namibia, Zambia.

Habitat: Freshwater.

Notes: This Southern African species is more common in the Okavango Delta and East Caprivi ( Brown et al. 1992). The snails can aestivate for long periods ( Kristensen et al. 2010 a), their colourless egg clusters are laid on top of rocks above the water line ( Appleton & Miranda 2015).

Type locality: Southern edge of the Kunene River, Angola ( Mousson 1888) .

Sources: Connolly (1912: 257, as Ampullaria occidentalis ; 1939: 553); van Bruggen (1966 a: 109); Brown & Kristensen (1989: 11); Brown et al. (1992: 16); Appleton (1996: 19); Brown (1994: 62); Jansen van Rensburg (2001: 29); Appleton (2002: 72); Appleton et al. (2003: 58–68); Appleton & Miranda (2015: 126); GBIF (2023 b).

Conservation status: Least Concern.