Last night all of asudden one of my giant danios cant swim.. hes at the top of the water not sick, staying upright. When he tries to swim his whole body curves... He stays at the top, and he does not look sick.. I am guessing he broke something? What should I do im really flippin out. Will these heal? all I can think about is if I should put him out of his misory... He just pretty much stays perfectly still at the top flapping all of his fins but his back, and the back fin is clamped... what should I do????