My Male Swordtail Just Had Fry?

I have two male swordtails in a 29 gallon tank with some male mollies, and we just had about 15 swordtail fry. It's obvious they are swordtails because the molly are dalmation and black, and the swordtails are gold/orange, and the fry are gold/orange. How can this happen? We got the male about 2 months ago from a local fish store, and about a month ago he started getting fat on us, and now he is no longer fat since we found the fry. My wife and I did some reading and it's pretty obvious that the males are the ones with the swords on their tails and both of the orange guys definitely have long swords and look like males. I will try to get some pictures of them, but we are very confused!!

 

Hmm... well by process of elimination that male must be female! congratulations!!!

Do you need any help with raising the fry?

 

Yeah, I don't think it's as big of a mystery as you might think. Or you have a miracle fish!!!

 

Does it have a gonopodium or not? That should be the surest way to tell. Only males will have them.
Because of inbreeding and line breeding it could be possible for females to start developing male characteristics, such as a sword. The same has happened with other species when they have been intensely line bred (ex. apistos). The natural distinguishing characteristics between males and females start to blur.
On another note, I once bought a male and a female swordtail and after a few weeks the female started growing a tail and developed a gonopodium. I did some research and read that some fish can occasionally change their sex.

 

Does the fish just have the sword tail extension, or is it a lyretail? Because a female Lyretail does have extensions on the caudal. And when put with a normal finned male, they do get pregnant. A photo showing the analfin or gonopodium will either clear this up or make it really confusing!

 

Yes as stated a picture please, some females have fin extensions when their tails get nipped (lyretail are particularly bad about this because the tail forgets where to stop growing to, one of my female lyres has a huge section of fin from the bottom lyre to almost the center of her tail - I know mine are female from the analfin). the analfin gives everything away, I have a female jet black that has a funny extension to her tail but she is still female by her analfin which is fan shaped.

 

Here's the best photo I could get of the female with the sword, but now that I've read some of the comments, I'm not sure that really looks like a sword. It was not supposed to be a lyre tail... hmm.

Swordtail-dadmom?

• fmagic
• Jan 1, 2018

Here's the other male swordtail in the tank:

Swordtail-red

• fmagic
• Jan 1, 2018

Somehow managed to get a good picture of one of the fry...

Swordtail-fry

• fmagic
• Jan 1, 2018

 

Do you need any help with raising the fry?

We've done pretty well with molly fry in the past, so I think we'll be okay. The biggest challenges is we are already at capacity, and out of friends to give fish away to! We have been trying to keep boys and girls separated to prevent this, and this just threw a wrinkle in that plan. We left the fry alone and mother nature has not done anything with them... they've all survived so far, all doing well and all are actually growing well, fast! I was waiting to separate the fry, but at this point, they now join everyone else at feeding time and I've been making sure to break up the flakes so they can get small pieces.

 

It doesn't quite look like a male other than the tail, is the dorsal and analfin slightly folded? It could be that it is a female that was dosed with hormones to appear like a male.

 

Here's the best photo I could get of the female with the sword, but now that I've read some of the comments, I'm not sure that really looks like a sword. It was not supposed to be a lyre tail... hmm.

To me the first picture looks like a lyre tail with a short top extension and long bottom one, but it is still too hard to determine the gender because we can't see the analfin very well.

If you can't get us a better picture then use this to check for yourself. It's a diagram off the internet illustrating an analfin (female) vs. a gonopodium (male) on platys but it's the same concept.

 

It is a lyretail, not a very good one, but I think it is taking on male characteristics. There has been so much genetic messing around with Swordtails that they are doing and becoming things that they shouldn't under normal circumstances. As a lyretail, even if it does become male it should not be able to breed.

 

I tend to agree with your statement. Thank you for sharing.

I have two male swordtails in a 29 gallon tank with some male mollies, and we just had about 15 swordtail fry. It's obvious they are swordtails because the molly are dalmation and black, and the swordtails are gold/orange, and the fry are gold/orange. How can this happen? We got the male about 2 months ago from a local fish store, and about a month ago he started getting fat on us, and now he is no longer fat since we found the fry. My wife and I did some reading and it's pretty obvious that the males are the ones with the swords on their tails and both of the orange guys definitely have long swords and look like males. I will try to get some pictures of them, but we are very confused!!

Have heard about this happening before. Several responders have made suggestions as to how this may have happened. In my opinion any one of those things are possible. Cases such as this one seems to be a common occurrence with Mollies, Swordtails, and Platys. I have two male swordtails in my aquarium. I just hope that one of them does not change it's sex. I have had swordtails and platys before. They are prolific breeders. I do not want that in my life right now.