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.

Over the weekend, I purchased my first emerald crab.  In the same trip, I purchased two more cerith snails and one more nassarius snail, bringing the totals to five cerith and three nassarius snails.  Unfortunately, I found the emerald crab lifeless on the tank bottom yesterday, with a nassarius snail completely covering the carcass.  I decided to try again and went out and picked up two emerald crabs today.

I’m trying to combat a bubble and hair algae problem that was introduced to my tank after buying a mushroom-covered rock from a local fish store.  I’ll be measuring two things in the next few weeks:  (1) Emerald crabs’ effectiveness in removing bubble algae, and (2) Emerald crabs’ compatibility in a reef tank atmosphere.