I would think the name would sujest that they are preditory in nature and if they can get their claws on something meaty they will eat it... I would use a glass in catch them get them out.. everything I have read says they will eat the tank mates and anything that is put in it. They get farly large to for freshwater. I would catch and return to LFS advise of misshap and ask for a return of money as no one advised of the nature of these crabs.

Bill