keithp
Fishaholic
When I was younger I used to have a tank full of swordtails, and I noticed a few of the largest females eventually turned male, even after they had been pregnant. Why does this happen, and can they mate once they turn male?
Hi Laura
I have to disagree with you about female swordtails not being able to breed once they have changed sex. In the absence of male fish, a dominant female swordtail (and other livebearers) will often change sex and become a fully functional male to keep the species alive. However, the majority of fry will be female and only a very small percent turn out to be males.
it's pretty bizarre isn't it. You end up with super sized males. I first saw it years ago when a big female green swordtail changed. I ended up with a male about 4inches long (body size) with a 2inch swordtail filament. It was about 3 times the size of the normal males.