A bunch of them are definitely not reef safe, or even fish safe. It would be cool to have some of the coral eating varieties in a specialized rock cleaning tank.. got GSP or palythoa running amok? Throw the rock in with these guys..
I've got one of these guys (not so little anymore) in my little tank. Calcinus eleganstle. He molts about every three weeks. This last time he did it while at the highest point of the tank. He just stood on top of the rock and ejected the whole piece. When the carapise comes off, the legs keep the same vibrant colors. This time I couldn't retrieve the shed shell and hope the other crabs eat it.
