I've had the goby for about a month, who immediately settled into one of my pistol shrimp's many burrows. I thought they had paired up because whenever I saw the shrimp, the goby wasn't far away. The goby was usually seen hanging outside of a burrow filtering sand, in typical WM goby fashion. For the last few days, the goby has been up on the water surface all day long, just swimming around, head usually pointed up but not always. I've had WM gobys before and have never seen one stay on the water surface like this. Parameters are good, temperature is good, and none of the other fish seem distressed. Any idea what's going on with the goby? I tried to find the shrimp with a flashlight and can't find him, but that's not unusual. The shrimp has been moving a lot of sand around the last few nights, though. I wondered if with the sand movement, maybe a burrow collapsed? As I was typing this, I took the flashlight and looked under the tank through the sump and found the shrimp, who seems fine. Weird!!