Do I have two male swordtails?

Hi so I have had these two in my tank for the past few months or so. I thought the orange one was the female when I got her at my LFS because she didn't have a tail. Now recently, she has doubled in size and looks to be growing her tail, which can only mean she is actually male. I wanted to confirm this before thinking of sending her back to the store since I don't want two male swordtails in my tank. They have always gotten along together, swimming next to each other peacefully, which got me not thinking about it. I could be wrong, but that does look like a sword on her now

 

Definitely both males

 

Darn, fr?! That would explain why I have yet to get any swordtail babies. Looks like I'll take a trip back to my LFS tomorrow and see if I can exchange him for a female. I thought he was a female when I pick him out when he was smaller.

Do the males not have their sword when they're younger?

 

Yup, definitely both males.

You can differentiate between male and female livebearers by looking at their analfins. Females have a rounder, more triangular shape and males have a spiky, slightly longer shape.

The picture below has the male on top and the female below him. Hope this helps

 

That pic is of platys tho, not swordtails?

 

That pic is of platys tho, not swordtails?

Uhm, aren't swordtails a type of platy? Doesn't really matter, the analfin gender differentiation technique is the same for all livebearers (e.g. guppies, platys and mollies)

 

That pic is of platys tho, not swordtails?

That's ok platy and swordtails can cross breed

 

Like a lot of species some males are "late bloomers'' and might show their characteristic colours/fins later on. For younger livebearers I try and use the gonopodium (male genitals) as a sexing technique as it's usually correct.

 

Two male swordtales get along as long as there are no female swordtales or female platy in your tank. The presence of females will start aggression between male swordtales. The dominant male will hunt the weaker male. If you wan't to keep more than one swordtale male, then go for at least five males in one bigger tank (>25 Gal.). The agression and fighting will split between the males.