Female swordtail (Xiphophorus hellerii palenque) developing a sword (with the colors of the male in her sword). As you can see, the gravid spot is still there. This is not a pseudo gravid psot but a real gravid spot. She also had batches of fry along the way. She's about 10 months now.
It's known that older swordtail females that won't give reproduce anymore can develop a sword and an elongated anal fin but in those cases it won't get the black seam in the sword. The MSX genes generate morphological changes in fin tissue in female swordtails by overactive MSX genes. This is a hormonal influence. But this female isn't that old yet.
But this female shows also the black seam in the sword. I just have to wait and see wether this sword will become longer or if it will remain like this.
Her anal fin has not changed.
It's known that older swordtail females that won't give reproduce anymore can develop a sword and an elongated anal fin but in those cases it won't get the black seam in the sword. The MSX genes generate morphological changes in fin tissue in female swordtails by overactive MSX genes. This is a hormonal influence. But this female isn't that old yet.
But this female shows also the black seam in the sword. I just have to wait and see wether this sword will become longer or if it will remain like this.