I just came across these bizarre fish. They are apparently quite common in public aquariums, fisheries and in Japan, juveniles are used as novelty gifts or something like that. Lumpsuckers have inspired Ponyo. They aren't good for home aquariums. Finnish aquariums don't have them, but some Swedish ones do. Yay!
I have never heard lumpsuckers are difficult. In fact as rockpool fishes they ought to resist a fair few environmental stresses. Can you help?
Have to check the exact dates but if I remember right Lumpsuckers were the first marine fishes ever bred in captivity ! Already before 1960 at least at Artis - Amsterdam Zoo bred them succesfully but as said, have to check the exacrt dates.