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Ideal temperature for ideal sex ratio

Discussion in 'Husbandry / Breeding' started by Happyfins, Oct 27, 2017.

  1. TCMontium

    TCMontium Active Member

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    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?
  2. Mike Wise

    Mike Wise Moderator Staff Member 5 Year Member

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    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.
  3. Matthias.couckuyt

    Matthias.couckuyt New Member

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

    Mike Wise Moderator Staff Member 5 Year Member

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

    Matthias.couckuyt New Member

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  6. Matthias.couckuyt

    Matthias.couckuyt New Member

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    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.
  7. Matthias.couckuyt

    Matthias.couckuyt New Member

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