Swordtails: how long before you can determine sex?

I have two young swordtails that look like they are going to avoid being eaten by the bigger fish. Theare approximately 6 weeks old. At what age will their sex become apparant?

How long before you can determine a swordtails sex? I have two young that look like they will survive, but if more than one is a male I will have to give him to the pet store. Thanks for any input.

 

The soonest I have ever beenable to tell is 45 days.
It is more usually about 3 months.

Dino

 

The soonest I have ever beenable to tell is 45 days.
It is more usually about 3 months.

Dino

Thanks! I'll just have to wait it out then.

 

I don't no but I would sur like to no because I am thinking bout breeding them soon
dan

 

the way to sex a sword tail is ..only males have the sword on the back tail and females are more rounder then males
my 2 sword tails are lovely there such pleasent fish to watch

 

the way to sex a sword tail is ..only males have the sword on the back tail and females are more rounder then males
my 2 sword tails are lovely there such pleasent fish to watch

Yes, but at what age does the "sword" become apparant?

 

The appearance of the sword on males from the same batch of fry varies from fish to fish, but a good average on time before appearance of the sword would be 6-9 months, though some do start to grow before that.. a better way to determine the sex of the fish would be to check the analfin which develops before the sword does.. the male's analfin is more phallic in shape.

 

Good information Richard. Thanks!