This morning, my male danio looks very odd. He has a dent in his spine just behind his head that makes him look almost like a tiny Chinook salmon. He's bloated and has a whitish color to his sides. And he's hanging at the top breathing hard. I really hope this isn't TB, and I'm positive he didn't look this bad yesterday. I've had my zebra danios for about a year and a half, so could it just be old age changes? Can anyone tell me their lifespan/old age changes? Does TB come on this quick? And if so, is euthanasia the only solution? I'm going to pick up some clove oil at the store just in case, but this may be the first time I've had to euthanize one of my fish!