# Incubation temperature accuracy



## Lingy21 (Nov 20, 2013)

Hi everyone, 

Like the title suggests I just have a question concerning incubating eggs in order to hatch a certain gender and how accurate this actually is? Does anyone have any idea if this is a reliable way of guaranteeing the sex of a hatchlings? 

Cheers


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## mike taylor (Nov 20, 2013)

*Re: RE: Incubation temperature accuracy*



Lingy21 said:


> Hi everyone,
> 
> Like the title suggests I just have a question concerning incubating eggs in order to hatch a certain gender and how accurate this actually is? Does anyone have any idea if this is a reliable way of guaranteeing the sex of a hatchlings?
> 
> Cheers



Yes reptiles incubation at higher temperatures will make girls . At lower temperatures will make boys . But it's ify at best .


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## Lancecham (Nov 20, 2013)

"IFY" is a good word for this. Higher or lower temps just increase or decrease the percentage of males and females. But the percentage is not as high as some breeders selling temp sexed babies make it out to believe.


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## N2TORTS (Nov 21, 2013)

Sex-determining mechanisms in reptiles are broadly divided into two main categories: genotypic sex determination (GSD) and temperature-dependent sex determination (TSD).
Species in the genotypic group, like mammals and birds, have sex chromosomes, which in reptiles come in two major types. Many speciesâ€”such as several species of turtle and lizards, like the green iguanaâ€”have X and Y sex chromosomes (again, like mammals), with females being "homogametic," that is, having two identical X chromosomes. Males, on the other hand, are "heterogametic," with one X chromosome and one Y chromosome. Other reptiles governed by GSD have a system, similar to one found in birds, with Z and W sex chromosomes. In this caseâ€”which governs all snake speciesâ€”males are the homogametic sex (ZZ) and females are the heterogametic sex (ZW).
In temperature-dependent sex determination, howeverâ€¦â€¦â€¦â€¦â€¦â€¦


Alex Quinn, a Ph.D. candidate at the Institute for Applied Ecology at the University of Canberra in Australia

http://www.scientificamerican.com/article.cfm?id=experts-temperature-sex-determination-reptiles


JD~




Lancecham said:


> "IFY" is a good word for this. Higher or lower temps just increase or decrease the percentage of males and females. But the percentage is not as high as some breeders selling temp sexed babies make it out to believe.



Lance your right .....According to the article it also could result in this scenario .... â€œIt is quite possible that there are other species of reptiles with more complicated scenarios of temperature reversal of chromosomal sex. There are certainly many known examples of fish and amphibians with GSD, in which both high and low incubation temperatures can cause sex reversal. In these cases, all genotypes (from ZZ and ZW to XX and XY) are susceptible to reversal by extremes of incubation temperatureâ€


Another great insight on the subjectâ€¦â€¦
â€œMost laboratory investigations on egg incubation have been done at constant temperature but it is important to know how sex determination operates when incubation temperature fluctuates, as happens in natureâ€¦.Very little is known about environmental factors other than temperature regulating sex differentiation in chelonians. Recent work has suggested that eggs incubated under 'dry' or 'wet' conditions may produce different sex ratios. However, more information is needed before the influence of dryness or wetness on the development of chelonian embryos can be assessedâ€¦.There are discrepancies from field observations that have not yet been fully resolved but there is no reason to reject the view that sex determination in chelonians is largely the same under natural incubation as under artificial incubation. Field observations not only confirmed laboratory experiments but provided additional information. Thus, the sex ratio in chelonians with temperature-dependent determination is influenced partly by the threshold temperature of the embryos and partly by the mother's choice of nest sites and, in large nests, partly also by the position of the eggs within the clutch.â€
http://www.britishcheloniagroup.org.uk/testudo/v2/v2n3sex


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