freaky gender change

aquadude

about 3 months ago i got 2 female swordtails and just today i noticed that one of them has a sword on his/her tail.is this normal? also yesterday my one male, my assorted Swordtail died of fin rot.

Lupin

Just one of the late male developers.

aquadude

but he was already fully grown when i bought him, and the lady at the fish store said he was a female

Lupin

Like I said, he could only have been a late developer. You don't see most advanced hobbyists advising you to buy small males with fully developed swords. They're stunted most likely and swordtails do not stop growing at 4-5".

Oldman47

It is not at all unusual for a fairly old "female" Swordtail to turn out to be a male. Some swords develop the sword shaped tail quite early in life while others do not develop one until they are about 3 inches long.