Occurs in the Mekong, the lower and middle Xe Bangfai, and the lower Nam Theun basins (Ref. 27732). Found in Ban Hang Khone in the middle of the mainstream Mekong River just below the Great Khone Waterfalls in Khong District, Champasak Province (Ref. 37767). Inhabits rapids, slow deep reaches of the Mekong basin at Hat Village, Muang Khong District and makes an upstream non-reproductive migration in December-February and downstream migration in July-August (Ref. 37769 ). Observed to undergo migration and fished heavily at the fishing village of Ban Wernsonkhram on Don Hat (Hat Island) above the Lee Pee Waterfalls (Ref. 10431). Interviews with fishermen strongly suggest that population in Southern Lao Mekong mainstream has declined some 20 or so years ago (Ref. 37769 ). Aquacultural stock reportedly has been introduced from China into the Mekong basin in Laos (Ref. 33488). Also Ref. 4792, 30857, 43281.