Harlequin tusks are fantastic fish. IMO, especially the Australian variety. Although they usually don't get as tame as some fish, they lose their shyness over time. Mine can be hand fed. They should have plenty of places to hide & feel secure; but once comfortable, will spend most of their time in the open.They usually don't bother anyone and don't like to be bothered. they usally do well with most triggers; but I did have to move a big niger that kept nipping. Sargassum & blue throat triggers seem to be fine with them. I've never kept them with groupers; my experience with groupers isn't a good one--every grouper I ever had outgrew the tank or became very aggressive. IMO, they need huge tanks and equally aggressive tankmates. IMO, large angels, lions and tangs make ideal tankmates.