Update: I did buy a Tasseled Filefish in November last year. Shortly after my many specie of brains started showing bite marks, I never saw F'ugly bite them though. I had just added an aggressive amount of Zeolites to the tank though, so I came to the conclusion that the damage was caused by too aggressively stripping nutrients from the tank. I removed the Zeolites, and the corals recovered for the most part. In the beginning of April I witnessed F'ugly biting the Symphyllia (not just a nip, he bit it 7 times in a row), and he also took to eating Zoas (Palys were fine). F'ugly ate 5 Zoa frags, and nearly wiped out 7 Zoa colonies before I caught him and banished him to the sump. He is now happily residing in a friend's SPS dominated tank.

Brown matted file fish
 

I have had one for several months now. The aptaisia are no long evident..occasionally I see a tiny one but soon disappears. I think if I banished the file fish the aptaisia would take over again:( It readily eats mysis and other frozen stuff. I have not seen it eat anything else but have to admit my zoas look pruned and certainly aren't spreading like they used to. I really don't want an aptaisia tank again.

Are these fish pretty shy?? i got one last week, and haven't seen it since.

Ya, they tend to hide a lot. Once they get used to who feeds them they will come out when you approach.

I bought one of these on the weekend, and he was eating aiptasia within 30 seconds. Awesome little fish!