Centropyge nox

Lore & Background

Centropyge nox was first formally described in 1853 by the Dutch ichthyologist and herpetologist Pieter Bleeker, with the type locality given as Ambon Island in Indonesia. The specific name nox means 'night', referring to its bluish-black colour. Some authorities place this species in the subgenus Centropyge.

The midnight angelfish is uniformly bluish-black in colour with an irregular yellow blotch immediately to the rear of the gill cover and above the pectoral fin. Its dorsal fin contains 14–15 spines and 16–17 soft rays, while the anal fin has 3 spines and 16–17 soft rays. It attains a maximum total length of 10 centimetres.

This species is found in the Western Pacific Ocean, ranging 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. It occurs at depths between 10 and 70 metres, commonly in coral-dense parts of outer reef slopes, though occasionally recorded from lagoon areas and channels. It shows a preference for habitats with dense and varied growth of benthic invertebrates. Typically encountered as solitary fishes or as pairs, it lives in harems of 3–7 fishes. It is a herbivorous species that feeds on algae.

Reader's Guide

Centropyge nox, the midnight angelfish, is a small marine angelfish of the family Pomacanthidae, found exclusively in the Western Pacific Ocean. Its significance lies in its distinctive uniform bluish-black coloration, which is broken only by an irregular yellow blotch behind the gill cover—a feature that aids in identification. The species was first formally described in 1853 by Dutch ichthyologist Pieter Bleeker, with the type locality at Ambon Island, Indonesia. Its specific name, nox, meaning 'night', directly references this dark coloration. Ecologically, it inhabits depths of 10 to 70 metres, favoring coral-dense outer reef slopes but also occurring in lagoons and channels. It is herbivorous, feeding on algae, and is typically seen alone, in pairs, or in harems of 3–7 individuals. The midnight angelfish occasionally appears in the aquarium trade, making it of interest to marine aquarists. Its distribution spans from the Ryukyu Islands to New Caledonia and the Great Barrier Reef, and from Indonesia to the Caroline Islands. Some authorities place it in the subgenus Centropyge, reflecting ongoing taxonomic discussion.