Try to quarantine her. Most fish will pick on a weak or sick fish even if they are not normally aggressive. Are there any signs of illness at all? Is there any possibility she may be pregnant? If she is fairly new she's probably pregnant. Guppys can have multiple batches of fry from just one...
Tank size:20 gal QT tank
pH:7.2
ammonia:0
nitrite:0
nitrate:10
tank temp:79°f
Volume and Frequency of water changes:50% water change every Friday.
I got a new angelfish yesterday to add to my 60 gallon. He/she is in QT right now but I noticed that one of his/her eyes is I bit bigger then the...