Nice female. Also you may wanna try not having the pictures lined up
as you do makes it alot harder to read comments. I do agree that you
made a good decision on not putting her down. I do believe it is a birth
defect. I believe even after thousands of spawns you may never see a
convict without a tail but that can just be a result of having better
gene's from not being so inbred. Inbreeding can cause birth defects
like missing tails, fins, shorter bodies, deformed mouths, ect.
Keep an eye on the fry as they grow that they dont also end up with
birth defects.