Ideal temperature for ideal sex ratio

[TCMontium]

Do temps and pH affect different species in different ways? My panduro produced overwhelmingly male offspring. My cacs a s mentioned above overwhelmingly female. My agasizzi pretty equal amounts of male and female.

Different species of apistogramma may have different sex ratios at the same temperature and pH, but not in the opposite direction. Higher temperatures and lower pH always means more males (as far as I have seen in the studies of Römer and tested myself). Are you sure all three species you bred had the same temperature and pH values from hatching to the 2 months of age?

 

[Mike Wise]

Each species will be slightly different depending on where they originate. Still, based on studies by Römer & Beißenherz, temperature is the primary factor. Unless you succeed in raising 95+% of a spawn to maturity, like Römer did, you really can't know the actual sex ratio from a spawn.

 

[Matthias.couckuyt]

When does the temperature and Ph apply...?
When there are eggs? When they just hatched? First week? Month?...

 

[Mike Wise]

Sex is determined after spawning, withing 6 weeks, so adjust the temperature when fry appear.

 

[Matthias.couckuyt]

Thanks Mike!

 

[Matthias.couckuyt]

It's for my A. Ortegai.
I would like to have more females.
Now temperature is 26°c.
I should go to 24 - 25?
They spawned yesterday so should hatch sometime tomorrow.

 

[Matthias.couckuyt]

Sorry, answer was already in this tread.
Will go to 22-23°c.