Depends on which ones. Most are not anywhere near reef safe. Copper Bands have a certain amount of value because they eat aptasia like there's no tomorrow. But even they should not be trusted in a reef tank. If you use one to eliminate the Aps then you should put it in a FO or FOWLR system after it has done its job. They are beautiful fish however. :agree: :agree: Do your research on the requirements for the different species. Like other types of fish, some are easier to keep. Some are hardier. Others should just be left in the ocean because they don't last in an aqurium. Just be informed so that you know what to expect. That's my 2 cents....
I have 2 Copperbanded, one in each tank. The one in my show tank I have had for over a year and I have not have any problems with it. The second on is in the seahorse tank and I have had him for a couple of months. He started out a little rough by getting ich, but it has cleared up and it is looking really nice.
I had a raccoon butterfly for awhile. Very nice fish. Not reef safe, of course. Was a bit of a picky eater at first. Actually, it always was. Liked mysis shrimp though, and one time I had some live clams from the seafood store that we had dissected in class, and it gave one of the opened ones to the butterfly. It LOVED that clam...just absolutely stuffed itself, eating up that whole clam really fast. I don't know how it was able to eat so much all at once.
It also ate Anemonia majano anemones and Aiptasia. I think it also ate a few stray mushrooms and zooanthids that happened to be in the tank I put it in (I think it is amazing that these fish are able to deal with the nasty toxins in zooanthids!). Probably would have eaten lots of other corals too it it had the chance, but I really don't know.