Expect a long wait. I've had my crabs for a bout 3-6 months now and haven't seen any noticable growth, however, I don't pay much attention to them.
There's LOTS of crabs that don't reguire shells, however, within my knowledge very few of them stay small and many will happily eat your fish if they aren't fed enough to keep there bellys full.
There's LOTS of crabs that don't reguire shells, however, within my knowledge very few of them stay small and many will happily eat your fish if they aren't fed enough to keep there bellys full.