My Swordtail is becoming male

[Patrick_G]

I had a trio of swordtails but the male died. The only surviving fry from their first batch in my tank was female. Recently she decided to grow a sword and gonopodium. Sorry about the out of focus pic, He never stops moving! 
 

He gets a to keep his old name “Glen Fry” 😁

[Guppysnail]

It is crazy that you posted this, Thank you.  The last two male CPD in mom n Dads tank had a fight a few weeks back. I put the video of the fight in my journal.  They injured one another pretty bad and neither made it.  The girls all have big egg bellies. I have been watching close because I’m worried about egg binding.  The small juveniles won’t be ready to breed for quite sometime.  I noticed over the course of the past two weeks or so my one girls fins getting red like the boys. She is slimming down a bit and also displaying some male type behavior and getting the gold strip on top like I have only seen in boys.  
I know I’ve seen documentaries on some fish that can change out of need but I thought…no way on earth was I possibly witnessing this…crazy old lady you are seeing things.  Hmmm…now I really wonder if that’s exactly what I’m seeing.  I’ll try to get pictures.

[Colu]

I remember reading about how swordtails can change sex

[gardenman]

I've seen it before. I had a trio of females I'd put in a tank and one of them became a male. Male swordtails are typically smaller than females but the females who transition to become males are huge. Doubters will say, "They were always male, and you just didn't notice the gonopodium." Uh, no. The reason I didn't notice the gonopodium is because it didn't exist. It's a neat trick and is more common among marine fish, but some freshwater fish seem to pull off the sex change stuff too. I would guess a combination of stress and hormones in the water play some role. When I broke my femur and spent 15 days in the hospital, my swordtail tank had eleven fish in it and only two were clearly males. Fifteen days later with the lights on 24/7 and no food, other than what they could scavenge (snails), there were now multiple males (seven I think.) 

[Hannah Parker]

That's so cool! I had a platy who changed from female to male a while back. But he messed up my ratio doing that! There were other males and really no need, but he just felt like it I guess. Very cool thing to get to see

[Patrick_G]

On 6/30/2022 at 6:15 AM, gardenman said:

I've seen it before. I had a trio of females I'd put in a tank and one of them became a male. Male swordtails are typically smaller than females but the females who transition to become males are huge. Doubters will say, "They were always male, and you just didn't notice the gonopodium." Uh, no. The reason I didn't notice the gonopodium is because it didn't exist.

Yes, exactly. My fish is bigger than a typical male and still has the female body shape, but has a clear gonopodium and the “sword” is getting longer every day. Being the only fry, he was the most watched fish in the tank. I'm 100% sure  he didn't have a gonopidium previously. 

Edited June 30, 2022 by Patrick_G

[Scotts Guppy Haven]

I use to have sword tails a long time ago and loved them, if I was to get back into them again I would get the wild type.

[ccc24]

Fish are fascinating creatures. It’s like Jurassic Park - life will find a way 

[Torrey]

On 6/29/2022 at 10:02 PM, Patrick_G said:

I had a trio of swordtails but the male died. The only surviving fry from their first batch in my tank was female. Recently she decided to grow a sword and gonopodium. Sorry about the out of focus pic, He never stops moving! 
 

He gets a to keep his old name “Glen Fry” 😁

I recently went down the rabbit hole of opportunistic, protogynous fish after a discussion about puffers.

Apparently, it is a lot more common than is frequently discussed and typically requires a stress induction event.

Which makes me think that my "how did this happen" endlers may be doing something similar. Typically, it's very easy to see a gonopodium (rather distinctive) and remove males as soon as they hit sexual maturity... but I have had a couple of incidents now where fish over 6 months old, who clearly did *not* have a gonopodium in a holding tank, developed a gonopodium. Until I started the autistic rabbit hole, I was beginning to think I just couldn't trust my eyes any longer.....

On 6/30/2022 at 5:35 AM, Guppysnail said:

It is crazy that you posted this, Thank you.  The last two male CPD in mom n Dads tank had a fight a few weeks back. I put the video of the fight in my journal.  They injured one another pretty bad and neither made it.  The girls all have big egg bellies. I have been watching close because I’m worried about egg binding.  The small juveniles won’t be ready to breed for quite sometime.  I noticed over the course of the past two weeks or so my one girls fins getting red like the boys. She is slimming down a bit and also displaying some male type behavior and getting the gold strip on top like I have only seen in boys.  
I know I’ve seen documentaries on some fish that can change out of need but I thought…no way on earth was I possibly witnessing this…crazy old lady you are seeing things.  Hmmm…now I really wonder if that’s exactly what I’m seeing.  I’ll try to get pictures.

As much as you watch your fish, I would say if you think you are seeing it, there's a 95% chance or better that you are seeing it happen before your eyes.

 

@Colu thank you for sharing what you read!

 

Due to some of the reports I am seeing of accelerating evolution, I do wonder what else may play a role in this happening in our tanks? Or has this always been happening, and just not noticed/discussed?