Temperature affect on sex ratios of Apistogramma bitaniata question..

[starforsaken]

Hello,

Alright... I have some eggs I took away from parent A. bitaniata on friday. It is monday morning and they have not hatched, however, the eggs have not fungused either. Anyway, the temperature of the water is 72F.

I ran out of heaters do to a recent epidemic of apisto eggs everywhere and these were the last fish to spawn.

I know temp and pH affect A. cacatuoides sex ratios quite dramatically, thus I was wondering if it had a similar affect on A. bitaniata.

thanks
coby

 

[fishboy20]

Romer published his findings about temperature and affects of sex ratios in Apistogramma in his Mergus Cichlid Atlas. The findings were that the lower the temperature, the more females in a given spawn will occur. pH is usually secondary to temperature but can be an important factor in some species like A. borellii and A. caetei. The best temperature to raise Apistos at is usually near 78-80 F. A. bitaeniata was not used in his experiments however and seeing what you end up with would be interesting to see.

~Jeremy

 

[Mike Wise]

Actually A. bitaeniata was included in his 2 scientific papers (Römer & Beisenherz, 1995 & 1996). At 72ºF/22ºC your fish will be 90%+ females. But don't worry, you still have time to alter this. The sex of Apisto fry is not determined at the time of egg laying or hatching. Römer found that it is the temperature that which the fry are raise for the first 6 - 8 weeks that determines their sex ratio. So if you want to have a more even sex ratio, now would be a good time to buy an extra heater & raise the rearing tank's temperature to 79ºF/26ºC.

 

[starforsaken]

Thanks both of you!