Identified by a single dark spot at the base of the soft dorsal fin.
A frogfish to about 13 cm, variable in colour through cream, yellow, pink, red and brown, with a body that is smoother than the warty species and lacks the long appendages of the hairy one. The identifying mark is a single conspicuous dark spot, usually ringed paler, at the base of the second dorsal fin — the “coin” of the alternative name — which is present at all sizes and in all colour forms.
Prefers hard cover to open sediment, sitting among rubble, on sponge and in the broken ground at the foot of a slope, where its outline is broken by whatever it is sitting against. Recorded from about 3 m down to 40 and beyond, deeper on average than the frogfish of open muck. It is worth being careful with this name: small frogfish across the region have been reported as juveniles of this species for decades, and in Indonesia many of those records are now understood to be Nudiantennarius subteres. A genuine nummifer has the spot.
Older references list it as Antennatus nummifer.
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.