Nieces fish: matted fins

Question
Bethany,
I have had bettas for several years now with very little problems but have been unable to figure out what is the matter with my niece's fish...I gave my niece a betta for Christmas which they are keeping in a 2 gallon aquarium with an airstone that is enclosed in a tube to prevent water motion and a bottom filter, not a surface one.  I have not seen Cocky (named for the mascot of the SC Gamecocks) myself yet but have been unable to identify the symptoms described by my aunt.  She says that he seems healthy and they've kept the water clean, he's still eating fine and he's still active, not resting on the bottom or near the surface.  She described him to me as his fins looking long and matted, almost like he needed a trim or them to be combed through.  I haven't been able to find a common disease that would cause this problem alone.  Do you have any ideas?  

Answer
Rebecca,

Let me do some research on this topic. I will get back to you within 2-3 days. These are odd symptoms and I have heard many different variations on the types of illness it could be. Once I get a positive answer, I'll send you another message.

{Send your email address to LstFllnANGL@Gmail.com and I can email you freely)

-Bethany