# Guppy fry and temperature?



## Fairy (Jul 20, 2010)

I Heard a rumour today about temperature, like in reptiles, Can effect the ratio of females to males? Is it true? If so what's the temp difference needed? I'm guessing warmer more females? Anyone else heard this? or am I just being stupid?


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## Corwin (May 23, 2010)

ive heard this before as well though i dont know how much truth is in it. My guess would be that its the same as all the random folklore about male/female infants in humans.


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## emc7 (Jul 23, 2005)

Its not stupid, its real in some fish species, search for scientific papers. But for most fish it makes no different. I wouldn't worry about it at all until I had one batch of a skewed ratio fry. Do research on your specific fish.

In some fish temp affects the sex ratio of the fry. I don't think the mechanism is well known. In some livebearers, it seems like more of one sex survive and you get fewer fish overall at some temps than other. In some egglayers, you don't get fewer fry, but the ratio does change, maybe the sperm is affected by temp. 

In most fish, eggs will hatch faster in warmer water.


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## TheOldSalt (Jan 28, 2005)

Whatever the reason, the higher the temperature, the more female guppies you'll get. I chalk it up to the females simply surviving better, even if equal numbers of each were originally born.


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## Fairy (Jul 20, 2010)

thanks guys ^^ i'll experiment  gives me something to do


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