Sorry if this is in the wrong place. Had anyone ever seen a yellow tang trap a goby to only a corner of a tank and not let him go anywhere and if he does get some where else chase him back to where he wants him. Well I be leave this is what he is doing. I watched the tang sift his body between the rock and glass just to touch the goby. I'm not understanding what he is doing really. He will chase him back to only one part of the tank and then keep him there what seems to be all day. I'm wondering if he is trying to stare out the goby. All the light sand is gone and the rubble I will call it is to big for the goby to mouth.