i purchased a trio of swordtails a few weeks ago. 2 females and 1 male. at first they were all looking good . one of the females even had babies. i tried to get her into the breeding new with all the babies, but she jumped out and hit the table pretty hard. i decided she had enough so i just let the babies be born in the tank with the rest. she was fine for about a week, but then i noticed the other female looking very scared. i barely ever saw her, and she had gotton a big red spot on the top of her head(this was about 4 days ago)the one i dropped looked fine, like nothing had ever happen(i felt terrible!!!!)but the other one was looking like something was maybe picking on it. all i have in my tank in 2 plecos, 2 snails, 5 mollies, 4 fancy tailed guppies, and the 3 swordtails. today when i woke up i noticed the one female with the red dot now has a few red spots and looks like it was just in a fight. her top fin is almost gone and her tail fin look ragged. and the "healthy" female is dead! i examined her and she doesnt look like she lost a fight. she looks fine and has no spots. what are the spots and how can i save my one female??please help!!