mantis shrimp

Hi guys, Just got back from China and saw loads of these guys in the restaurants. I have never seen mantis shrimp this big. All of them larger than my forearm.

So yesterday I saw a Mantis Shrimp (I am assuming it was a mantis shrimp) pop out of the rocks. He must have been there for quite sometime as I haven't added in anything new for a while now. This would explain the mystery of my missing invertebrates (a few months ago my cleaner shrimp both...