how to determine sex of guppys?

[wright4lfe]

anyone know when a person is supposed to be able to determine the sex of guppies? also, at what point am i supposed to separate the males and females?

thanks

 

[1tankneverenuff]

Feeder guppies or the more exotic/colorful types?

Also, once you figure out exactly what species you have, I believe the males are usually the more colorful ones.

 

[wright4lfe]

exotics.

the less colorful guppies are going to be sacrificed to the oscar/clown knife/bumblebee cat gods. the more colorful ones i want to separate out accordingly.

 

[lmw80]

In addition to the colors being brither and more amazing on the males and the tails being longer and flowier, male guppys have a differnt anal fin than females. It's called a gonopodium. This is how they mate with the female. Female's anal fins are more triangular, so if all else fails, you can try sexing the guppys this way.

 

[Matthi]

In plain laymans terms (I've gone through the guppy breeding thing myself), you look at two things - both are on the rear underside of the stomach.

Young males develop a special fin (previous post refered to it as a gonopodium). It looks like a long stick that floats backwards below/behind their stomach towards the tail fin.
The young females have a more translucent triangle fin in that position, which looks like a regular fish fin.

The second thing to look at is females have a "gravid spot" which is dark colored (dark gray to black). You can see it if you are angled behind and below the guppy - it will be a black spot on the ridge of their stomach.

 

[Guest]

Check in the breeding forum with this thread: http://www.aquariumadvice.com/viewtopic.php?t=46158
There should be enough information there (along with a pic) that will help you along.
HTH
-Stewie