Marine fishes in the Pomacanthidae family. Most are brightly colored and have disc shaped laterally compressed bodies.  They are closely related to Marine Butterflyfish and are distinguished from them by a spur like preopercle spine which grows off the gill plate. This spine can be clearly seen on the Three Spot Angelfish below

Threespot Angelfish (Apolemichthys trimaculatus) is also known as the Three-spot Angelfish and the Flagfin Angelfish

Marine Angelfish range in size from 6cm to 60 cm and many undergo dramatic changes in coloration during the ageing process. Many juveniles bear no resemblance to the adults.