So far so good with the emerald crabs.  They haven’t eaten any of my corals and have been nibbling on the nuisance algae in my tank.  The only downside that I’ve noticed is that they tend to hide a lot.  Other than that, these two little creatures are a great addition to my reef tank!

I would recommend keeping these in small numbers in case they do end up being problematic (a guy I know bought a ‘colony’ of emerald crabs only to find they nearly ate all of his mushrooms).  Plenty of people don’t encounter that problem when kept small in number.