Sword tail question

[starsman20]

I purchased 4 swordtails from my lfs about 6 weeks ago. I thought there was 1 male and 3 females.  Well one of the females started growing a sword so I moved it to another tank and bought another female.   Now again one of the females turns out to be a male.  I don't really want to leave 2 males with the 2 females (the bigger one is already picking on the smaller one) so can I have 2 males and no females on my other community tank or will they fight even with no females?

[lefty o]

sometimes they are okay, sometimes one wants to assert dominance. you just never know until you see how those individual fish act. more than likely, they will adjust to each other and be fine.

[gardenman]

In my experience with my neon swordtails (over a hundred of them at this moment) the later developing males tend to be bullies. They're very passive until they start to develop the swords, but once they do, they go into big bully mode and just abuse the smaller, earlier developing males. The earlier developing males tend to get along fine with each other in my tanks, but when one of the supposedly female larger, later developing males comes along, he wants to own the tank. Now my tanks are so crowded that the later developing males have a lot of targets to pick on and no one smaller male bears their brunt, but the bigger, later developing guys are kind of intense.  I had three large females and a younger male in my ten gallon quarantine tank keeping the cycle going and one of the females developed into a male and just went nuts against the younger male in the tank. He chased the other male nonstop and had him constantly on the run and there aren't a lot of places to run in a ten gallon tank. The younger male got moved out and the big guy is now happy with his lady friends.

[Yanni]

I know that the males that develop later are usually the ones that you want to keep with the females. Usually, they will pick on other fish because they are much bigger. I've found that those males are usually the better breeders to choose as well since they are so big and sometimes have better color and bigger swords. In a community tank, swordtails are a hit or miss. Some swordtails will be just fine in a community tank while others will just chase things around and harass other fish.