A lot of the clowns are slow swimmers and weak small fish that will not last very long in a natural reef without their host. They need natural host to make them comfortable. Without a natural host they will find things that they cuddle to to watch their back side. It is a smart fish that look for inner things, rather than something unnatural that could eat them.
I disagree with a lot of experts that some clown fish do just as well in aquarium without their natural hosts. This may be true with large agressive species like Tomato clowns or Clarkii, but not for smaller species like Percula, Ocellaris or Pink Skunk. Their behavior are so different with and without their natural hosts in a community fish tank. In a species tank without other large fish, they are comfortable with a flowerpot, but not in a large tank with large tangs, angels and Harlequin Tusk and the like.
Once you see Percula clownfish with Gigantea or Magnifica interactions in a community reeftank, nothing even come close, even if they use a BTA as host.
They are crack heads, mine hosts my torch in the day then at night he hosts my frogspawn
My tank bred clowns are mentally challenged. In the 3 1/2 years I've had them they have used for a host....1) my overflow 2) a large gonipora 3) a zoa colony 4) a rock with GSP covering it 5) an alveopora 6) and their latest choice a medium sized duncan colony.....
IMO, it is the reefers, not the clowns that is mentally challenge here. Not able or not willing to provide the best care for their animals. This does not mean that we should go out and purchase a Magnifica or Gigantea and put it in our reeftank if we have Percula. Better do our research and read up, so we can also provide the best care for our anemones. I do have a very soft spot (more likely spots) in my heart for clownfish and anemones, so please forgive me if I offended anybody here.
Many of us call a fish or an anemone stupid for not doing the things we want in our tanks. I tend to think of it a little different. It is us who are stupid for not provide them with what they need to thrive.