Occurs in the Mekong basin (Ref. 12693). Observed in small numbers in non-reproductive condition at Stung Treng in February 1994 (Ref. 10431). Below the Khone Falls, this species migrates upstream from the Kandal Province to the Khone Falls, mainly triggered by receding water levels at the end of the flood season (Ref. 37770). From Thalabowirrat in Stung Treng Province to the Mekong Delta, a downstream reproductive migrations occur at the onset of the flood season, triggered by a combination of early rainfall and rising water levels (Ref. 37770). Also Ref. 36654.