I have 5
I have 5
I have five in my 55g bb, sps dominated tank, they come out at night and do seem to end up on my colonies, sadly I had one crab that came with a colony, a supposed "friendly," but everytime he was on a coral the coral later died, I never saw AEFW, but one of the corals has no come back, I am not sure if he just disturbed the PE or just was actualyl munching away. BTW he wasn't a Mythriax, he was somethign else, small fuzzy crab, blue eyes, tiny, lived in my monti colony, but eventually migrated. I have 2 acro crabs and they are awesome eating any paarsites.
cheers
David