Xenia Tree being eaten?

[claire481]

Help! my Xenia tree recently split into three smaller trees. Two are doing great, one seems to have most of its tentacles nipped off. I only have a bangaii, a clown and two gobies, plus some hermits and a pistol and cleaner shrimp. Why would something nip at the fingers of this one tree and nothing else in the tank? Could it have something to do with the fact that my green clown goby likes to hang out in the branches?

 

[Roblox84]

Have you personally seen something nipping at the tree? What is your lighting? I have a kenya tree and for a while I had insufficient lighting for it in my tank so that made it drop a lot of branches. It almost got to the point where it was only the stem remaining, but then I upgraded my lighting and it hasn't shed a branch ever since.