The doublesash butterflyfish has a silvery-white body marked with three broad yellowish-brown vertical bands, another one runs through the eyes, and there is a similar coloured caudal peduncle.

[3] This species is omnivorous and feeds on macroalgae,[2] as well as benthic invertebrates such as polychaetes, crustaceans, hydroids and ascidians.

[4] The doublesash butterflyfish was first formally described in 1921 by the English ichthyologist Charles Tate Regan (1878-1943) with the type locality given as East London.

[5] Regan honoured the collector of the type, the Natal fisheries officer Harold Walter Bell-Marley (1872-1945), in the specific name.

[4] Some authorities place this species within the nominate subgenus Chaetodon but others consider it to be incertae sedis.