All the fry are GIRLS!! How do I get boys!!

[dnaelting]

What are the odds? We have about 25-30 guppy fry that are between 4 weeks to 3 months old, and all of them are girls. Not only that, but the 4 swordtail fry are also all girls.

Is there any way to influence the sex of the fry to maybe get a few males?

My tank params are:

ph 8
nitrite and amonia 0
nitrate 10
gh 14
kh 5

 

[Toirtis]

Are you certain the younger ones are female? It could be that the sex of the fry are being partially determined by something in the water, or even by water temperature (something that happens with many reptiles and some fish...not certain about guppies, though).

 

[DirgeDevil]

I'm sure you have some males. To sex them look for very tiny gravid spots.(only females have them, duh,but hey- some people dont know) They can be seen as early as 1 week of age, a magnifying glass comes in handy for this.

And the temp. doesn't affect the offspring, they produce males and females out of the same litter, but warm water will make your guppies grow faster.

 

[BillD]

It seems to me that I read somwhere that pH will affect the ratio. I can't verify this or remember where I read that. Perhaps someone can verify or deny .

 

[Apocalypse_Gold]

It can take quite a while for fry to develop a gonopodium so the gravid spot is the best method of sexing them. Females will have a darker spot above their anal fin.

 

[dnaelting]

I'll check again, but so far, looks like lots o girls.

 

[malkore]

pH or carbonate hardness might have an effect.
I know with Kribensis, softer acidic water yields mostly females while harder alkaline water gives you more males.

 

[dnaelting]

I have re-checked the fry. It's hard to convince fish to stay still and go in a line to get an inspection to see if they are a boy or girl fish. They seem to want to swim all over the place.

Anyway, it looks like I have a bunch of female fish and only adult males. Hopefully the next batch of fry will result in some males.

Just my luck, I am still the only male in the house.... 8)