Having A Hard Time Determining Gender

[slimeneo]

Sorry for the late response here, but the other platy that has the same unclear anal fin seems to be... getting fatter? I'm not sure if she's (or he's..) pregnant, but the stomach drops down lower than the other fish. Or maybe it's just my imagination....

There's one male who's anal fin is obviously a stick, is pretty aggressive and likes to chase nearly everyone except the one in the picture I posted. Not sure if he's trying to mate or he just hates everyone, lol.

 

[FishBlast]

Sorry for the late response here, but the other platy that has the same unclear anal fin seems to be... getting fatter? I'm not sure if she's (or he's..) pregnant, but the stomach drops down lower than the other fish. Or maybe it's just my imagination....

There's one male who's anal fin is obviously a stick, is pretty aggressive and likes to chase nearly everyone except the one in the picture I posted. Not sure if he's trying to mate or he just hates everyone, lol.

Does it have a gravid spot? (black area near the anal fin on the abdomen).
A well-fed male can look fat too.
Though it might be a female who keeps her fin folded most of the time, like mine does.

 

[the_lock_man]

I just did a quick read through of this thread so it is time to correct some misconceptions. Fish, at least common livebearers like platies, do not change gender ever. The fish that we buy in a typical shop have been pushed for maximum growth so they are often not mature enough to sex when we buy them. That can lead to the misinterpretation that a female is becoming a male. All immature platies look like females so seeing one gradually take on the male characteristics can lead to that misinterpretation.
The fish in the picture does look like a late developing male.

A simple 2 males and 2 females is fine unless you happen to have an especially aggressive male. In that case the safer 1 male to 2 females would be better, a lot depends on the individual fish involved.

Only one little problem:
Stuff like this does happen, and I've had it happen to an orange swordtail female of mine as well, had fry from her previously too.
But I didn't have any way to test if they can reproduce, while others claimed that if they have an all female tank that have previously given birth (all of them), one will become a male and all fry it fathers will be female. But I'm not sure about this one, like I said, never had the chance to experiment with that.

Um, yeah, maybe not.

I have read of instances of older swordtail females developing a sword, but in terms of genuinely, genetically, changing gender, such that it is capable of fathering fry, NO. I'm with OM, it doesn't happen.

 

[FishBlast]

I just did a quick read through of this thread so it is time to correct some misconceptions. Fish, at least common livebearers like platies, do not change gender ever. The fish that we buy in a typical shop have been pushed for maximum growth so they are often not mature enough to sex when we buy them. That can lead to the misinterpretation that a female is becoming a male. All immature platies look like females so seeing one gradually take on the male characteristics can lead to that misinterpretation.
The fish in the picture does look like a late developing male.

A simple 2 males and 2 females is fine unless you happen to have an especially aggressive male. In that case the safer 1 male to 2 females would be better, a lot depends on the individual fish involved.

Only one little problem:
Stuff like this does happen, and I've had it happen to an orange swordtail female of mine as well, had fry from her previously too.
But I didn't have any way to test if they can reproduce, while others claimed that if they have an all female tank that have previously given birth (all of them), one will become a male and all fry it fathers will be female. But I'm not sure about this one, like I said, never had the chance to experiment with that.

Um, yeah, maybe not.

I have read of instances of older swordtail females developing a sword, but in terms of genuinely, genetically, changing gender, such that it is capable of fathering fry, NO. I'm with OM, it doesn't happen.

Never said I saw cases where they'd father fry. Only that they do change exterior shape after giving birth to fry. (which makes them not sneaker males if they had fry previously, but doesn't make them males either, just infertile).