Ahhh Lotus I just lost my diamond gobie did the same thing. After 2 years managed to jump through a small space at the back of the egg crate, Its sad when they do that. I attempted to replace him with a pink spotted gobie and a pistol shrimp pair. After acclimation the gobie headed down to a spot under a rock and has set up home there for the past few weeks and the pistol shrimp was promptly eaten by the brittle star (I think as I haven't seen him once since I put him in the tank and haven't heard him either) Nice may as well go throw 20's out into the street. I will try and pair up Mr. Gobie with a tiger pistol in a few weeks. Not sure of the best way to do that, my other gobie/shrimp pair came together and haven't been separated since.