Who is the culprit?

[Kitteness]

Okay about a month in a half ago I added a arrow crab and anenome crab to my reef tank. Since then I have lost 1st sally lightfoot, 2nd coral bandit was completely torn apart but i rescued him just in time(which also leads me to another ? he only has a couple legs 3 antenae and no claws but he still alive and i have in the sump so i can take care of him. will he survive and how long will it take for him to get his body parts back if so?)
and now my coral catfish has been attacked and has open wound which i am treating now also. I never had these problems before i added them. Do you think it is one or the other or just both of them being way to aggressive? I can't seem to catch anyone doing it of course. So I wondering what to take out and take back to store? I'm leaning on taking both back. They are very well fed also.

 

[LeslieH]

Which kind of anemone crab do you have? A Mithrax or a Neopetrolisthes?
http://www.saltwaterfish.com/m-inverts/Anemone-Crab.html
http://www.reefs.org/hhfaq/pages/picture_pages/faq_anemonecrab.html
The Neopetrolisthes is a filter feeder. In the picture you can see the modified antennae with fine hairs it uses to capture particles from the water. The Mithrax is pretty mild mannered under most circumstances but like an emerald crab (another species of Mithrax) it has potential to do damage. The real culprit though, is probably the arrow crab. They're well known for killing other organisms in a tank, even reaching down into feather tubes to eat the polychaetes.

 

[bertoni]

I'd place my bet on the arrow crab as well. They can be very aggressive and destructive.

 

[Kitteness]

hmmm.. ya i was thinking it was him but he has such tiny claws but i suppose one snip is all it takes. The anemone crab isn't those ones though maybe I have the wrong name this little critter is a hermit of some sort who collects little anemones and puts them onto his shell. He has an awesome personality for a hermy crab that is but he is fast and seems kinda calm at times them wild at others I call him weirdo!

 

[LeslieH]

Oh - an anemone HERMIT crab. Another meat eater & potential killer.

 

[Kitteness]

Okay I figured as much I knew he was a meat eater it was just wishful thinking that he wouldn't attack stuff on my part then. Thanks for the help.