I have a 8" diameter GBTA. I am missing a 2" diamond goby. Not under rocks. So my guess is he either jumped or the BTA got him. I'm leaning toward jump but his remains are nowhere to be found....what you think?
Diamond gobies are notorious for two things 1) jumping and 2) starving to death. Could be either one. If it starved, the CUC (assuming you have starfish and hermits) would've made quick work of the body.