this is happening on all of his fins though not just the tail fin. I started with 5 crayfish in the tank and am now down to 2. The gar also used to eat as soon as i put a feeder in the tank. Now it's hit and miss. Sometimes 20 minutes to eat a couple of feeders, sometimes a couple of hours and once in a while i'll even see them in the tank the next day. Is this damage permanent to his fins or will he recover from this. He has been acting very weird as of the last few days. He used to hang out at one spot at the top of the tank now he spends more time on the bottom. Is there something i can get to fix this??