Swordtail breeding

[Beth_obrien2424]

So, I was wondering what kinds of fish swordtails can breed with. I have three female swordtails that I have had for about a year.
One of them looks very pregnant weirdly. I was wondering if it was possible for her to have bred with another species as I only have the three female swordtails, no males. If not, I might have a bigger issue to worry about with why she is so big.
also, is there a way to distinguish whether they are actually swordtails and not platys, as I have seen pictures of platys that look a lot like them. I am just trusting the aquatic shop that they are sword tails.

 

[Naughts]

Can you post a photo of the fish please?

 

[Beth_obrien2424]

Can you post a photo of the fish please?

This is her

 

[Naughts]

Swordtails and platties are both in the genus Xiphophorus and can breed together so it is difficult to say she is definitely 100% swordtail, if she is more than 3-4cm that would lean towards more likely swordtail.
She does look pregnant, can you see a gravid spot (dark patch to rear of belly)?
Livebearers are breeding machines, she could have bred with a platy if you have a male, or she could have held a sperm packet from months ago when she may have been with a male, one of your other female swordtails could have even become a male!
There are other members who have more knowledge that could help you pin this down, hopefully someone else will reply.
In the meantime I think the fish looks very healthy so try not to worry.

 

[Aussie_Bristle]

In an all girl tank, the dominant swordtail female is known to change gender to keep the population continuing. Has one of the girls got any show of a sword looking tail?

 

[Beth_obrien2424]

In an all girl tank, the dominant swordtail female is known to change gender to keep the population continuing. Has one of the girls got any show of a sword looking tail?

Oh wow I didn’t know that. None of them have a sword tail yet, can they still breed before they get the sword tail? And are there any other signs they are have switched genders

 

[Beth_obrien2424]

Swordtails and platties are both in the genus Xiphophorus and can breed together so it is difficult to say she is definitely 100% swordtail, if she is more than 3-4cm that would lean towards more likely swordtail.
She does look pregnant, can you see a gravid spot (dark patch to rear of belly)?
Livebearers are breeding machines, she could have bred with a platy if you have a male, or she could have held a sperm packet from months ago when she may have been with a male, one of your other female swordtails could have even become a male!
There are other members who have more knowledge that could help you pin this down, hopefully someone else will reply.
In the meantime I think the fish looks very healthy so try not to worry.

It just seems strange to me. I have had her for a while and she has never been around any males, other than mollies and they are unable to breed apparently.
I don’t think she has a gravid spot but I’m not entirely sure what I’m looking out for
I had no idea that female swordtails can become males, that’s pretty cool! Thanks for the information

 

[Salty&Onion]

It just seems strange to me. I have had her for a while and she has never been around any males, other than mollies and they are unable to breed apparently.
I don’t think she has a gravid spot but I’m not entirely sure what I’m looking out for
I had no idea that female swordtails can become males, that’s pretty cool! Thanks for the information

In stores males and females are usually mixed together so that could be an answer.
Does any of your swordtails have a stick like fin near their vents?

 

[Beth_obrien2424]

In stores males and females are usually mixed together so that could be an answer.
Does any of your swordtails have a stick like fin near their vents?

I have had them for too long for it to be that. They were on their own together in the tank when I bought them.
They all look like they have fan fins to me. Do they look the same as a male molly does?

 

[Salty&Onion]

I have had them for too long for it to be that. They were on their own together in the tank when I bought them.
They all look like they have fan fins to me. Do they look the same as a male molly does?

All livebearers have the same genitals

 

[emeraldking]

So, I was wondering what kinds of fish swordtails can breed with. I have three female swordtails that I have had for about a year.
One of them looks very pregnant weirdly. I was wondering if it was possible for her to have bred with another species as I only have the three female swordtails, no males. If not, I might have a bigger issue to worry about with why she is so big.
also, is there a way to distinguish whether they are actually swordtails and not platys, as I have seen pictures of platys that look a lot like them. I am just trusting the aquatic shop that they are sword tails.

The picture shows a female red wagtail swordtail. Swordtails can only crossbreed with platies.
In your case it´s most likely that she has sperm packets stored and is using one or more of those packets. Note that female livebearers as such can store sperm packets for over a year. She might have mated before you got her. But hasn´t used one or more sperm packets until now. So, that´s not weird at all...

 

[emeraldking]

All livebearers have the same genitals

Not quite. Yes, an ovoviviparous male livebearer has got a gonopodium but the shape of it differs per genus. But male members of the same ovoviviparous genus (so, from different species within the same genus) have similar shapes. Which means they do differ in shape but are compatible enough to crossbreed. The genitals of an ovoviviparous female livebearer are shaped in a way that they can only mate with the gonopodium of a male within the same genus. So, even when a male of a complete different genus is chasing a female of another genus and directs his gonopodium in her direction, an actual mating will not take place.

 

[Beth_obrien2424]

O

The picture shows a female red wagtail swordtail. Swordtails can only crossbreed with platies.
In your case it´s most likely that she has sperm packets stored and is using one or more of those packets. Note that female livebearers as such can store sperm packets for over a year. She might have mated before you got her. But hasn´t used one or more sperm packets until now. So, that´s not weird at all...

oh wow, they can hold onto the sperm packets for that long?
do you think she is definitely pregnant then and there is not a problem with her?

 

[emeraldking]

O

oh wow, they can hold onto the sperm packets for that long?
do you think she is definitely pregnant then and there is not a problem with her?

Wouldn´t worry about her...
Yes, they can hold on to sperm packets for that long. You do read a lot that it´s just a few months (mostly that's been written at forums). But that´s not correct. They can definitely store sperm packets for over a year.

 

[Retired Viking]

She looks exactly like my female right before she had 13 fry. Now I have a fry tank that I was planing on changing over to something else before the fry showed up -at least they are cute fry