Acantopsis dialuzona is a loach native to the swift, clear streams and rivers of mainland and archipelagic Southeast Asia, Indonesia, Peninsular Malaysia, Thailand, but Southeast Asia outside its range, including as Acantopsis. A. choirorhynchos because of the lack of taxonomic resolution in Acantopsis. It can also be found in flooded fields.
The horseface loach or horsehead loach, formerly known as Acantopsis choirorhynchos, is now recognized as belonging to this species.[1]
Under Maurice Kottelat's review and revision of the loaches in 2012, this species name is considered to be a junior synonym of A. dialuzona.[1]
A very similar species is the unofficially named longnose loach, Acantopsis octoactinotos, from which the horseface can be distinguished by the latter's down-turned (horse-like) nose. Additionally, the horseface loach buries itself in the bottom substratum (if silt or fine sand); the longnose loach does not. The horseface loach is fast moving; the longnose is rather slow. However, the longnose is more aggressive, regularly feeding on juvenile fishes.
The horseface loach's native substrate is one of sand or gravel, wherein it will characteristically burrow itself. These loaches spend much of their time buried in the substrate, leaving only their eyes uncovered. Due to this incessant burrowing, any live plants should be potted to avoid uprooting. The use of floating plants is recommended, as these loaches prefer subdued lighting. Horseface loaches are not picky eaters, but live food (such as tubifex) is relished.
The horseface loach is most active at night and mostly keeps to itself. It attains a maximum size of in length, but is considered mature from ., it had not been bred in captivity. It was first imported into Europe in 1929 by Edmund Riechers of Hamburg, Germany.