Crooked Tail

       I seem to be having horrible luck with my green glofish, which is disappointing. As of last night I managed to total, 3 green glofish deaths, to one orange glofish death, and 0 (knock on wood) reds.
      The first one I noticed getting sick but unfortunately nothing I did seemed to help him. The second... well he didn't look so good when I first got him, but I was determined to give him a chance... he didn't last the night either. This most recent I have no idea what was wrong. The other day he was seemingly fine, and then last night he was dead. I'm running a dose of medication in the water just in case, but everything, and everyone else seems fine, so it's a mystery.
      Anyway, I got a new fish (because I really don't like my other green being all alone) and put him in the tank... As I was transferring him from the bag, to the transfer box I noticed something weird... He looked normal enough from the side... but looking down from above I noticed something weird.

His tail is very obviously crooked... I don't know why or how. For now it doesn't seem to bother him too much either. He's beating other fish too food, even if he does swim a little weird, he's pretty active.
      I know a lot of people would take him back but... I just can't. Because he's mine now, and like that second fish I'm determined to at least give him a chance. I take him back, he'll probably be euthanized. And he seems okay right now... he's just a little gimpy fish.
      So I'm hoping for the best and getting attached to him because he really is adorable. I'll just have to keep an eye on him and make sure he doesn't have any trouble ^^