Pila occidentalis

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.