Perhaps I should have posted this in the disease section, but I'd rather leave that section for people who are having emergencies. My crowntail, Finley, passed away in July. He developed dropsy (not sure what the root cause was). I had him for a year. During his time with me, I knew there was something that wasn't quite right with him. You know how when bettas sort of "tread water"? Like when all but their pectorals fins is perfectly still? It almost looks like they're hovering. When Finley would do this, he would rock from side to side, like something was physically wrong with him that made him incapable of "hovering" properly. I'm sorry I can't describe it any better, but that's exactly how it was. I was just wondering what that could have been so that I can identify if I ever see another betta with the same problem.
Info:
Finley was approximately 1 and 1/2 years old.
He lived in a 2.5 gallon filtered, unheated tank.
Water changes were 100% weekly in the beginning, I bumped them up to one 50 and one 100% weekly in the last six months or so of his life.
He ate Omega One Betta buffet flakes and bloodworms as treats.