Ambastaia nigrolineata is a vulnerable species of loach found in the Mekong basin in Southeast Asia and China.

[1] It occurs in clear, fast-flowing riffles and hillstreams with moderate currents and substrates composed primarily of sand.

It is known to feed on insect larvae and other benthic organisms.

[2] Ambastaia nigrolineata reaches 8 cm (3.1 inches) in standard length.

It is sometimes seen in the aquarium trade, but it has historically been confused with the only other species in the genus, the similar A.