Swordtails peaceful?

[batski]

Just how peaceful are swordtails in a community tank really?

My girlfriend has a couple of beautiful green swordtails. The male is pretty cool but the female seems very stressed or restless. She swims fast and sometimes she swims up and down the walls of the tank, as if she wanted to go further. Sometimes she pics on other fish too.

Is this normal? Do you think she would calm down if we got one or two more females? Or is it ok for them to live as a pair?

 

[Blinky]

Livebearers are best in groups of one male to two, three, or even more females. The males are relentless - they want to mate constantly. They can harass females to the point of exhaustion or death, since in the confines of an aquarium there's no escape from the male.
How big is the tank? Swords can get large - over four inches long - and they're livebearers, so you're likely to end up with fry before long. If the tank is large enough I'd say run out and get two more females to spread the male's attention around and give your girl a chance to rest. If the tank isn't large enough to accomodate 4-5 medium sized fish or more, you might want to consider returning one of the swords - if you just keep the male, you'll never have to worry about housing fry.

 

[batski]

Thank you for your answer! It's a 250 L tank. Wouldn't a swordtail feel lonely without any other of his/her own species?

 

[Blinky]

Oh, that's pretty large, so (providing the tank isn't already fully stocked with other types of fish) you've got enough room for more females.
Many people keep just one sword, platy or guppy, and they seem fine on their own. I keep mine in groups, but that's because I'm nuts about the little guys