zerotona

Does anyone know when the male swordtail fry start developing their swordtail? I have two swordtail fry and I am pretty sure one is male. They are about 8 weeks old so still small but look like actual fish now and not just little tadpoles.

I'm really just curious as the swordtails are both completely orange and a male with a sword would look cool

Dino

Generally they develop at about 3-4 months, depending on strain/species.
You can usually sex them eariler as the females will develop a gravid spot at a younger age.

manjil

It can develop earlier if u give them nutrious food.

swords3711

it takes a while and it varies often
some males grow up early
when their anal fin changes, then they will begin growing the tail spike.
If they start to get large and still look like females, just wait and they might become males
I had a marigold sword that was female when i got her but in a few weeks her anal fin rounded over and he got the tale spike
it was really neat
this sword was probably a year and a half judging from his size