I recently made this post about my Baby Betta:
He seemed to have his belly bulge overnight, and then it subsided the next day. Now he has it back, when I came home I found him propped up against his heater. He is paler and seemed to be barely breathing (he seems to be active now-still pale, and bulged).
Here's the better news, all seven of my Betta Fish seem to have the same bulge, along with my roommate's Betta. One of my Betta's seems to be shivering(every so often). I just don't understand what it could be.
I do my best to not cross contaminate anything between my fish, the only thing they seem to share is the food I feed them, and the water from my tap.
They all just received a water change on Saturday-all 100%. Some of them I am not seeing droppings, and the rest of them seem to have normal droppings. They are all actively swimming and being themselves, but my baby is definitely off, and the one I mentioned who is shivering.
If anyone has any suggestions on what it may be, and advice on how to fix it, please let me know as soon as you can.