Toward the rear of the body of immature Koran Angelfish (fig.), the pattern of lines forms semicircles, which gave rise to this species' other common name, i.e. Semicircle Angelfish.

The pectorial fins are transparent and yellow in colour, whilst the area around the snout is also yellowish. As it matures, the greyish-brown body colour at the centre changes little by little into yellowish.