I was afraid to bring this up earlier because of a possible misunderstanding, but one of my tanks is having problems and one of my smaller dragon gobys passed today. I have seen many fish die, but for some reason when the dragon goby died I was a little more upset.
I was going to let him perish on his own, but it was lasting for hours and he seemed to be in a tremendous amount of pain (thrashing around violently etc) and I ended up putting him in a small tank with baking soda in the water so he would pass out then die in his sleep from lack of oxygen. I put him under a filter cover in the water so he wouldn't float and breathe the air. Luckily this was very quick.
Autopsy results confirm my suspicion of a problem with his swim bladder. He had a swollen gut really badly and he was floating uncontrollably. When I opened his abdomen, I noticed a big black sack that was very large. At first I thought it was a massive goby turd, but then I saw that farther back. It looks like it must have been his swim bladder. It felt very spongy.
Unfortunately, his skin seems to be tougher than his bones so I think I will leave the rest of him for some of those beatles or something.