EDIT: How about having 1 male clownfish with 2 females? Will there still be a fight for dominance? It's just that it seems that 3 of them would be perfect for the view, for me at least
Unfortunately it doesn't work that way with anemone fish. In anemone fish society, the female is in charge of the anemone. The next most dominant fish in the group becomes her male partner. All the other anemone fish remain juveniles, which are neither male nor female. If one of the dominant pair are removed (get eaten), then all the fish move up one spot in the pecking order.
eg: The female dies. The male turns into a female and takes over the anemone. The most dominant juvenile fish turns into a male and becomes the partner for the old male, which is now a female. All the juveniles move up one spot but they all remain juveniles.
eg: The male dies. The female remains in control of the anemone. The most dominant juvenile fish turns into a male and becomes her partner. The remaining juveniles move up one spot in the pecking order but remain juveniles.
It only takes a couple of weeks for the fish to change sex. If you have a pair of anemone fish, they must remain together at all times. If you separate them for more than 24 hours, any males and juveniles will start to turn into females and will fight if put back together.
If you buy anemone fish, buy a bonded pair, or get 2 small (baby) fish and put them in the tank at the same time. Have one fish slightly bigger than the other. The bigger more dominant fish will turn into a female and the other will become a male.
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A crown fish (a center piece fish) might not work in the tank with anemone fish unless the tank is big. In a smallish tank (2 foot square), the anemone and its fish will probably become the centre piece (main viewing point) in the tank. If you have some rock in the tank, you could add some shrimp, snails and maybe a small species of dottyback (Royal Gramma) and that would add more variety. But a pr of anemone fish in a small tank will always restrict what you can keep with them.
The 2 species I mentioned previously (Amphiprion ocellaris and A. percula) are the 2 smallest and most peaceful out of all the anemone fish, so you could probably get away with a small dottyback and shrimp with them. But you would have to monitor them when they start breeding.
If you have two tanks (one above the other), and have them connected so the top tank is the show tank, and the bottom tank is a sump/ refugium, that would give you more water and provide a more stable environment for the fish and other inhabitants. It would also give you somewhere to put other fish if they get attacked when the anemone fish breed.