I had a perfectly healthy and very Hansom male Betta, until one morning I woke up and he looked like this (this is a picture taken today, a week after the first time i noticed) From what I can remember it wasn't a gradual process. He has a heater, light, filter, a 4 Gallon tank,the works. The ends of his fins are perhaps slightly see through. But there is no black or red as described in other cases of fin rot. He eats like its going out of fashion, he makes bubble nests, has plenty of interaction with me and my partner and has silk plants and nothing to snare his fins on.
I don't know if this is tail biting or fin rot, but most refer to the latter being a death sentence and he's happier than I have ever seen him. What's going on here?