What would eat pulsing Xenia?

I notice a couple of nights ago that a xenia frag on the bottom of my tank had what looked like something ate 2 branches off, now this morning its gone and this was a good size frag at least 1"dia. base with a few branches left. I have been working nights so I couldn't check the tank at night but have tonight off. what should I be looking for out for that might eat that coral. All my other corals are unharm as of now. I do have a nice colony of Xenia on some LR near the top of my tank that I am worried about. I have had all my corals for a few months now and haven't added anything recently.

 

Got crabs?

 

not personally... but my tank has a boxer, emerald, small blue leg hermits. Then also a banded sea urchin, serpant star, fiji coral banded shrimp, peppermint, cleaner shrimp

 

No I don't have any damsels

 

I can at least tell you that these have never bothered my xenia:

emerald
blue leg hermits
peppermint
cleaner shrimp

 

LOL... Nice !!!

 

I didnt think so Its just wierd how after having this xenia for at lest 3-4 months and nothing added for about a month and that was just a leopard wrasse and mushroom leather coral. this frag was on a old sand dollar piece and it has been moved at least 4" when something had if for dinner. I have always looked at my tank with a flashlight at night least 3-4 times a week and never seen anything unusual other than a black snail with a cockroach type shell on its back and fast like one to.

 

well now its the waiting game the lights are off and hopefully I'll find out what bad little critter attacking my xenia is if its not still full from last night

 

Good luck on this one. Out of all your livestock, the only thing that popped out at me was the serpent star....just because I do not trust them. They can be evil.