im helping set up a tank at my university and am looking for some suggestions for stocking the tank. it is a 110 gallon display tank with a 50 gallon sump. about 125 lbs. of live rock in tank. not planning on adding any corals, just fish and inverts only. since the tank is going to be for behavioral observation i am looking for any suggestions of livestock that are particularly interesting to observe. particularly i would like some relationships between species like a shrimp and goby pairing.