Centropyge nox is uniformly bluish-black in colour with an irregular yellow blotch immediately to the rear of the gill cover and above the pectoral fin.

[2] Centropyge nox Is found in the Western Pacific Ocean where it ranges from the Ryukyu Islands in the north to New Caledonia and the Great Barrier Reef in the south, west to Indonesia and east as far as the Caroline Islands.

[1] Centropyge nox is found at depths between 10 and 70 metres (33 and 230 ft).5th[1] This species is common in the coral dense parts of the outer reef slopes, although it is occasionally recorded from lagoon areas and channels.

The midnight angelfish shows a preference for habitats which include dense and varied growth of benthic invertebrates.

[4] The specific name, nox means “night”, this refers to tilts bluish-black colour of the midnight angelfish.