A:As a matter of fact, I do :). Your betta has swimbladder disorder. "swimWHAT?" you ask? OK, here is our "Swimbladder 101" crash course.
The swimbladder is a handy little device that stretches inside your betta's body alongside his spine. The function of the swimbladder is to allow the fish to control where he wants to be as far as depth is and to maintain its position. Fishes that do not have a swimbladder cannot "hover" in place but instead are condemned to swim night and day (many of the fish that live in schools in the ocean do not have swimbladder).
Our bettas however are the "Deluxe" model and come standard fully equipped with a swimbladder ;) and since they do not have to swim to maintain buoyancy, they have the luxury to be as lazy as they darn please (which, usually is quite a lot LOL).
But sometimes the swimbladder goes bad. Too much food, or stress or sometimes certain diseases cause the swimbladder to malfunction. Sorta like electric windows on cars LOL they're great to have, until they stop working properly that is ;). Since bettas are 'made in Taiwan' ;), expect the bells and whistles to go bad on this model rather promptly LOL. What you are left with is a betta that cannot swim properly. The main two way things can go at this point are:
Betta cannot swim 'down' and maintain its buoyancy and floats pathetically at the surface, usually on one of its side. If that is the case you can usually SEE the swimbladder protrude as thought it is swollen or full or air (like a long balloon). You are likely to find it protruding from the side which is floating UP. Betta may try to swim down but it is like it is spinning its wheel for nothing and floats right back up. In a way, think of it as though you had little floatation devices around your arms (like kids do) and you were trying to swim under water. Pretty darn hard, huh? For Mr. Betta it gets very tiring so he will prefer to just 'lay there' at the surface. Although this lying around cannot kill him (as all lazy people and couch potatoes will attest LOL) it makes feeding very difficult because lining up the mouth with the food becomes an all time out effort (oftentimes a useless one). It might become necessary to hold the food with tweezers and aim it directly for his mouth cavity. In your case, you mention the betta is still flaring which to me indicates the ability to swim (at least temporarily) so that is a good sign.
Betta cannot swim 'up' and lies pathetically at the bottom of his jar. Going up to get a gulp of air or food is a huge effort and the betta immediately sinks right back to the bottom. In this case you will not see the swimbladder protruding. It is more likely to actually be contracted if anything (like a deflated balloon ;) ).