Do Environmental Factors Influence the Sex of Fry?

[Darb21]

So we've got some Endler's that are breeding (like thats tough )... and we're getting about 15 females for every male. Are there any environmental factors (Temp, PH, GH, KH, etc.) that could have an impact on the sex of the fry? Any tips to get more males?

Thanks!
-Brad

 

[rkilling1]

Look up Thermolabile sex determination and see if that helps.

 

[kimo]

When they are born Endlers (sub-species of guppies) appear to all be females. After 10-30 days the gonopodium will form, allowing you to determine male from female.

pH can have an effect on the sex of fry.

Presence of predators can have an effect on the number of fry that are born in a single drop. Usually seen only in the wild.

 

[bs6749]

As stated, pH can have an effect on the sex ratios during development as can temperature. I'm not sure if hardness can determine sex but it has been shown that hard water can cause sterility in some species such as cardinal tetras (wilds) that require soft and acidic water.

 

[Darb21]

My Temp is about 77 and PH is at 8.2 naturally, but am injecting CO2, so it stays around 7.2 via my controller... any ideas what changes I should make to get more males? -TIA!