A damselfish known only from the Revillagigedo Archipelago, holding a territory on rock and driving off anything that enters it.
To about 15 cm. The head and front of the body are light brown, the middle darker brown, and the rear third grades to whitish, with pale yellow on the soft dorsal, anal and tail fins. Most body scales have a dark margin. Juveniles are quite different: bright yellow with a dusky back, a dark spot at the base of the front soft dorsal rays and a smaller one on the upper edge of the tail base. The other damselfish of this size here is the whitetail damselfish, which is dark brown overall with the pale marking confined to a band on the tail base, where this fish is pale over the whole rear third.
Shallow rock, one to twenty metres. It is recorded from the archipelago with the occasional individual reaching the tip of Baja California; FishBase treats the Cabo San Lucas record as part of the range rather than as a stray. Eggs are laid on the bottom and the male guards and fans them. Holding a territory against other fish is characteristic of the whole genus, and every diver who has been chased by one will recognise it, but it has not been described for this species specifically. Listed as Vulnerable.
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.