A small deep-bodied chromis of deeper rock, usually in groups near the bottom rather than in open water.
To about 16 cm. Deep, oval and compressed, light brown with darker scale margins. The juvenile is quite different: blue, with a neon-blue stripe above and below the eye and a broad whitish band along the base of the dorsal fin.
The scissortail damselfish is the pair to separate it from, and the body shape does it: deep and plain here, slender with black tail streaks there.
Generally a deep fish, thirty to two hundred metres, but there is a shallow population in the Galapagos at five to forty-five metres, which is why it is divable there and effectively out of reach elsewhere. It feeds on pelagic crustaceans, fish eggs and zooplankton in the water column along reef edges.
Two things worth flagging. It has not moved to Azurina — it is still Chromis alta, unlike several of its relatives. And a Revillagigedo record was not confirmed in the sources consulted; the range given is Mexico, the Galapagos and one record from Cocos.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.