Hi Terry, I'm having problems with my pair of Watchman Gobies. I have tried to add more gobies at different times and they have been killed. I tried a pair of Two-spot Gobies and a Pink Bar Goby and a small Randall's. What bothers me the most is the way they have gone about it, it's like a coordinated effort, both watchman will look thru every little cave until they find the goby and double team him, like two Veloceraptors looking for prey. Is this common behaviour ? My tank size is 30x30x24 it's a fairly new tank about two months old, the watchman came from an older tank and have been with me for a couple of years. Any suggestions ? I have tried to move the rockwork around but that hasn't made a difference.