Xenia RIP

[Bartman]

I was doing a water change this evening and noticed that my Xenia, which is normally waving in the current up front, was missing. On further inspection its rock, previously wedged into a crevice, was gone too. After much hunting I found its rock, with just a tattered stub of Xenia flesh remaining, in a cave under my green brittle star. I am assuming he ate it. What's up with that??? Aren't these supposed to be reef safe cleaner crew types? Did I miss something?