Hey guys, my panda coradora has been getting a thick left arm fin and I call it a tumor. It almost twice as thick as his right arm fin. It's not the webbed part just the part he can kinda flap. His other fins are in early stages of decaying or being eatin away but I make sure he eats so it can't be malnutrition. There is only a goldfish (peaceful, i take him out and feed him separately) and another corydora. Proper water care, a lot of room, only started having decaying fins after this "tumor" arrived. My only hypothesis is that the tumor is stealing nutrients to grow instead of maintain his other fins. I don't know, anyone have any idea about a growing, hefty looking fin?