I have a blue spotted goby paired with a pistol shrimp. I just added the shrimp two days ago, and they paired instantly. My goby on the other hand has been in the 32cube for 2 months with other cleaner shrimp. Just this morning though, my goby went on a killing spree and killed one of the cleaner shrimp and starting chasing the other around the tank. I had to get involved and the force the goby to go back into its hole. Has anyone else had this problem?