Aww Sheldon... (I so have a geek crush on him.. :P )
I went through pages and pages of my long (too long of a list) of illnesses, but just as I figured, there isn't a specific illness, nor can I find what you are describing as a symptom of anything.
Is it with every breath, or just once in a while? I know once in a while is fine, and I've seen mine do it every so often. But if it's constant, then it makes me wonder what is going on with him. I'll keep searching and seeing if anything clicks, but off the top of my head, and going through roughly (so far) 60 different illnesses for fish, haven't found much about that issue.
He isn't showing any other signs of illness, correct? Or distress? Does it seem as if he is gasping at the surface, desperate to get air when that happens? Or is he just as casual as normal?
He's certainly not feeling well :( I got him 2 days ago, horrendous ammonia issues in his "tank" and he was on his side. He would shoot to the top for air. Once home, he was better but I put him in AQ salt. He got better, now he seems to be going back downhill. I noticed the large bubble from his gills this morning, it's not every single time but it's enough to notice. I'll have to keep an eye on him for a bit so I know really how often it is.
Poor guy :(
Is there any issues with his gills? I am assuming redness due to the ammonia, but is he breathing rapidly with them? Are they open partially or all the way continuously?
A part of me wants to say that the problem isn't with the air bubbles, but something else because when a betta takes in air at the surface, this drives out the air that is already in its labyrinth organ, and it expels this bubble of air through one or both gill openings.
Would also recommend not using AQ salt if he is having trouble with breathing.. Salt reduces the amount of oxygen that can be dissolved in water. Bettas do breathe air, but they also get some of their oxygen from the water.
Still can't find anything specifically for the bubble issue. Only thing that relates to bubbles is the gas bubbles disease.. but that would be bubbles under the skin..
Sigh.. wish he would show other symptoms, want to help him :(
There is a little redness from the ammonia. His breathing is slow and steady and gills are working normally except for the air bubbles, but he's not swimming much and just floating at the top. I switched him back to clean water but I really hold little hope that he'll pull through. So many switches for the little guy, I just got him adjusted to AQ salts. Seems like nothing is working for the little guy. I hope he pulls through.
Myates, it's me. I totally know Bettas breathe from the water LOL
Here's a small clip, seems to be both gills are doing this but not at the same time. It was the right earlier, now it's the left. And yes, it's happening every time he breathes now.
Hehe oh I know you know the fish :P I am blaming all my air-headedness on cold medicines..
I really wish I knew what to say, have yet to find anything that talks about air bubbles such as that (other then people saying it's normal). Maybe he has a blockage internally that is causing it, rather then a disease that is treatable? :( I'd PM OFL or Sakura, Darkmoon.. those are the only others I can think of that *may* know- since it seems to be stumping us :(
I do hope he pulls through though, he'd have a great home with you.