My watch man died a while back and my pistol shrimp has been alone. Last week I added a royal gramma to the tank, and it decided the caves the pistol shrimp made were better than the caves in the rock, and every night I see and hear it getting shot and beat up by the pistol shrimp. The gramma didn’t eat yesterday, and I haven’t seen it today so my suspicion is the pistol shrimp had enough of the intrusion. How do I prevent this from happening with every new fish I add? Would a watchman simply stop the problem?