Angelfishes have a deep compressed body; a small mouth with brush-like teeth; long, strong spine at the corner of the preopercle, as well as smaller spines on the preopercle, opercle, and under the eye; a single, un-notched dorsal fin; and very rough scales with distinct ridges on the exposed part, scales extend out onto the median fins; no "axillary process" (an enlarged scale) at the base of the pelvic fins; adults sometimes with small auxiliary scales between the main body scales.
Most angelfishes are inhabitants of tropical Indo-Pacific seas, being found mainly in the vicinity of coral reefs. They occur both solitarily or in aggregations. Many species inhabit shallow water, from only a few meters to 10-15m depth. Others are restricted to deep water. Angelfishes are favorite aquarium pets, well known for their brilliant array of color patterns. Species of Holacanthus and Pomacanthus exhibit dramatic changes in color pattern from the juvenile to adult stage. Most angelfishes are dependent on the presence of shelter in the form of boulders, caves, and coral crevices. Typically, they are somewhat territorial and spend daylight hours near the bottom in search of food. The diet varies according to species; some feed almost exclusively on algae and detritus, others such as the species of Holacanthus and Pomacanthus prefer mainly sponges supplemented by a variety of benthic invertebrates. Divers are sometimes startled by the powerful drumming or thumping sound which is produced by large adult angels in the genus Pomacanthus.
The family has a circumtropical distribution and is represented by about 91 species in nine genera; only four endemic species from 2 genera are known from the tropical eastern Pacific.
