Mine hosted a striped mushroom, and they're tank bred. I think that the instinct of the captive bred/raised clowns might lean towards hosting SOMETHING, but not specifically anemones while you may have better luck with ones caught in the wild (of course I don't advocate that, if you can get a fish captive-bred, you should, imo). I had hoped mine would host a frogspawn but when they went for the mushroom it was more or less just something to smile at, the neat way they like hiding under it, etc.