I caught this crab in my tank last night. I haven't added any kind of crabs to my tank since I set it up about 2 and half years ago so I am assuming he has been living in there since then. My snails would disappear right after i would add them and then I would find the empty shells under one of my rock structure. Finally one day i saw this huge crab and realized he was the culprit.
Based on my research I think this is a stone crab. I would like this to be confirmed. He is about 3-4 inches big right now. Also can I leave him in my sump without worrying about it nipping at the cords of my equipment in there? Thanks