I paid $110.00 for Dudley.....All the reading I've done says they do well in a species only tank....a 20L is what mine is in.
However, Scott Michael, says that the following are Potential Frogfish tankmates:
Soldierfishes, Squirrelfishes, Scorpionfishes, Groupers ,larger Hawkfishes, Snappers, Grunts and sweetlips, Swallowtail angelfishes, Pyramid butterflyfishes, Monos. Larger Hawkfish, Scorpionfishes, Groupers, and Snappers may eat a frogfish that can be swallowed whole.
Unsuitable tankmates:
Batfishes, Angelfishes, Butterflyfishes, Surgeionfishes, Triggerfishes, Filefishes, Trunkfishes, Pufferfishes, and Porcupinefishes. The species in the following familes that eat zooplankton are of little or no threat to frogfishes:Angelfishes, Butterflyfishes, Surgeonfishes, and Triggerfishes.
HTH,
Janey