White in front, flame at the back, with a pennant that never stops flicking.
A dartfish to about 9 cm, white to pale yellow over the head and front of the body, grading through orange to a deep red at the tail, with black margins on the rear fins. The first dorsal fin is a separate tall filament raised well above the back and flicked continuously, which is what catches a diver’s eye long before the colour does. The congener Nemateleotris decora, on this list as the purple firefish, is grey and violet with a yellow head and occupies deeper ground.
Hovers a little above a bolt-hole in rubble, singly or in pairs, feeding on zooplankton from the passing current, and drops into the hole rather than swimming off when pressed — which means a diver who has spooked one need only wait a minute. It is shallower than the purple firefish, common from about 6 m down. Recorded to about 60 m. Pairs hold a hole together and both use it, and the flicking dorsal fin is thought to be a signal between them as much as a warning.
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.
