Just a quick note: The reason I quoted a bubble tip is because of the type of clownfish that was mentioned. Different clowns grow to different sizes, and vary in aggression levels. The ocellaris is known to be one of the smallest species of clownfish, and it's host anemone tends to be a bubble tip.
The different species of clown have specific preferences in anemone species, and not all will work with just any anemone.
Something else to consider is whether the fish are wild caught or captive bred. Captive bred clowns don't always understand the use of an anemone, as this is a learned trait in the wild. Using an anemone is not strictly instinctual for them.
I hope this helps to clarify the information I posted earlier.