I've had my male betta for about 5months now and he acts pretty normal. He swims around and eats. He's in a 2 1/2 gallon tank.. He was originally in a 1 1/2 gallon tank next to my tv and I noticed he looked stressed so I moved him away from it and got him a new tank. But I have noticed his fins have gotten shorter.. Is this something I need to worry about? Help mee!!