Recently I noticed one of my black neon with a bit of a gut. I was wondering if it was bloated or if it was a female and it was ready to spawn. Any ideas?
As long as she is doing what black neons do, I wouldn't worry to much. You might want to add blanched frozen shelled peas that are smushed up to their diet occasionally just in case she is constipated.
I've had a regular neon like that for two years, with no ill-effects. I always assumed it was a female. I agree that you could add some peas, just in case.