my acropora has been getting white spots around the base. have seen this guy near and on the coral. anyone know the species? hes about the size of a quarter in full
Had a green emerald that picked at my sps. Thy are known for doing that from time to time. That looks like a crab I wouldn't want in my system. I don't know the species. Maybe someone else does though. I would keep it out of the tank though
That looks like an acro eating crab I had 2 in my tank as well flush him. People will say sump him but if you have any snails /hermits etc it will destroy them so don't bother. Not worth trying to save him I know from experience.
I found this link of someone who found a crab that looks almost identical to yours on reefcentral, someone responded that its harmless but its up to you what you want to do with it: