He has lost color, appetite, and is now a hunch-back. He has 2 other tank-mates, but a different species. I had another one that had a hunch-back, but she died. I have quarantined him, just in case. He would go up to breath when the other fish weren't up there. I feed him TetraFin Tropical Fish Flakes, and a crushed boiled pea every other day.