Scientific name: Hypsibarbus annamensis
Range: Unknown, but possibly central Vietnam
When last seen: 1936
Suspected reason for disappearance: The location was severely impacted in the 1970s by deforestation, though it is not known whether this is responsible for the population decline.
IUCN conservation status: Data Deficient
Facts: The species is only officially known from three specimens: one collected in 1936, and two collected in 1969 (without the location recorded).