The gray angelfish has a disk-shaped, compressed body with a large head and small snout.

[5] The gray angelfish is found at depths between 3 and 30 metres (9.8 and 98.4 ft) over coral and rocky reefs.

[6] In the northern parts of its range, the spawning season occurs in the summer, from April to September.

When they are ready, the pair swims upwards, bringing their bellies together to release eggs and milt.

The larvae live among the plankton until they attain a length of around 15 mm (0.59 in), after which they descend onto the reef where they settle.

[6] The gray angelfish has been recorded as a host for the following endoprasitic trematodes Antorchis urna, Cleptodiscus reticulatus, Hamacreadium mutabile, Hapladena megatyphlon, Hexangitrema pomacanthi, Hexangitrema pricei, Phyllodistomum pomacanthi, Pleurogonius candidulus, Pleurogonius mcintoshi, Pyelosomum erubescens and Theletrum fustiforme.

[7] The gray angelfish was first formally described in 1758 as Chaetodon arcuatus by Carolus Linnaeus in the 10th Edition of his Systema Naturae with the type locality given as "Indiis".

[8] When Lacépède created the genus Pomacanthus, he used Linnaeus’s Chaetodon arcuatus as its type species.