I have a recent 10g setup. I have 2 male Green Swordtails. Ive noticed this morning one of the males tail fins is completely eaten off. Its only been 2 days and its gotten worse. The only other fish in the tank are 2 x-ray tetras that were introduced yesterday, who are not to blame here I dont believe. Im pretty sure the dominant male sword is eating the other males tail. The pet store did not tell me to get 2 females for each male, so I wound up with 2 males. What should I do now to keep this one male sword from anymore damage?