ZTL thinks the aquarium only has the shaggy angler (A. hispidus) but I don't think this is that, looks much more like a black form of Commerson's frogfish (Antennarius commersoni) to me.
@ChunkyMunky pengopus very fair point, however I'm not aware of A. maculatus being as big as this chap (around 20cm) nor as massively built, and I haven't seen any of that species (at least not on google pics) with this near pure black colouration, the black individuals of that species usually have some other colour or pattern on the body as well.
