Earlier today, i watched my opaline gourami suddenly go spastic. He darted around the tank, was jumping, and eventually hit the glass and fell to the bottom, where his spine curved, and he seemed to not be able to get off the bottom of the tank. For a while he could not get up, was breathing extremely heavily, and basically freaking out. I don't have a hospital tank any more, so i fed the other fish to get them to leave the gourami alone, then walked out of the room because I cannot stand to watch a fish die. After about 15 minutes, I came back, and by some miracle, the gourami has gotten himself upright, and right now is hiding in the corner of a tank, but he is no longer lying on the bottom. He is still breathing heavily, but no where near as bad as what it was earlier. All the other fish are acting normal, no obvious sign of disease. Tank mates include a clown loach, 3 platties, and a RTBS in a 40 gal tank. I haven't checked water stats, but the tank has been well established for over two years, with minimal problems. So I have two questions. First is what can I do to help this fish? Second is what could have caused this?