I put an emerald crab in my tank a week before July 4th, he vanished a week later and I've never seen him since. I know you can't really answer the question but any guesses or similar experiences are appreciated. \n\nI looked in the rocks carefully with a very powerful flashlight for many days in a row. I looked at night for him. I looked under a few rocks for him. And yes I asked if anyone in my house had a crab dinner. but nada, zip.