ashley

My guppies just had babies a few weeks ago and I am wondering when and how can I tell what sex they are? I was "saving" the babies when I found a much larger one and do not know how old it is, however the others are 3 weeks old yesterday. My other guppy is about to pop as well. Any help would be great, thanks

ecnaj143

Its extremely hard to tell when their fry. You may have to wait til they get bigger!!

armadillo

I thought I could sex my 2m.o. molly fry but now I dont' know. They all seem to be females!

Dino

Most livebearer fry appear to be female until they are 2-3 months old.

armadillo

Oh noooo. I was hoping they were all females... I don't want to keep any males anymore.

pappyy3

If you're really observant you can actually start to sex your guppy fry from about six weeks of age.

Simply catch up a few fry at a time in a small glass container.

Hold the container at a hight where you can observe the bellies of the fish.

Young females will have begun to show a dark spot near their anal fins (their gravid spot - even though the're not gravid 8)

Young males will not display this spot.

There will always be some that you'll be unsure about - simply put these back into the aquarium and check again in a couple of weeks.

I used this method to seperate the sexes of young guppies when I was selectively breeding them to develop various color strains.

Found it was accurate 95% of the time! This methods is not perfect, and takes some practice but it does work!

armadillo

Oooooh. Thanks for the tip, Pappy!