sex and temp

[isaisbreetai]

Just wondering if anyone has noticed whether the temperature of the water has effected the sex of their fry (ie cold water produces more females)?

[BallAquatics]

I don’t have an answer for your specific question, but for what it’s worth here are my observations after raising hundreds of CPD fry.

Cool, (cold) water produces babies period. If the tank temperatures get around 80F and above, spawning stops. We had a very hot summer this year, (2010), and for about 3 months… no fry. When the tank temperatures dropped back into the 70’sF in late September, all my breeders started getting busy.

I don’t heat my breeder tanks, they are kept at room temperatures. They range from lower 60’sF in the winter months, to the mid 80’sF in the summer months. That being said, it seems as though I always have more females than males. I have never actually done any kind of study, but I like to send these fish out at a 1:2 or 1:3 ratio of males to females. Most buyers are looking at breeding and that’s how I set up my breeders. I bring this up only because I always seem to come out even when the fish are all sold… so I must have 2 to 3 times as many females as males typically.

Currently my breeder tanks are running around 64F. They are producing eggs at least once and often twice weekly. The same is holding true for my Danio erythromicron.

Dennis

[Tom2006]

Interesting stuff. Might need to cool my tank down a bit then

[poppedreng]

I have also reading something about that With lower temperature you get more females than males.
If i find the link i’ll share it

[Author]

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