Temperatures influence gender?

[gnarhimself]

Probably a silly question here.
Does temperate play a roll in the determination of the sex of corn hathlings.
I read somewhere that crocodiles "nests" temperatures are a direct influence with regards to the gender of the offspring.

Does this occur with cornsnakes as well,for example,if the temps are higher,do you get a higher ratio of males to females,and if the temps are at the lower end of the scale,do you get a higher ratio of females to males??


:shrugs:

 

[TripleMoonsExotic]

No, cornsnakes are not temperature sex dependent.

 

[gnarhimself]

Thanks Blckkat.

 

[PtDnsr]

Like Blckkat said it's not been proven to be temp dependant. I think that it will have some influence but that's only from my own, limited observations (and I do mean limited). If someone were to undertake a project like that it would be a lot of effort and very strict record keeping. I will say that my experience could also just be Murphy being nice to me as well (which if that's the case, will come back to haunt me someday). Just my .02

~Katie

 

[TripleMoonsExotic]

I incubated 9 clutches this year all at the same temperature and received a wide range of sexes out've the close to 100 offspring. Some clutches had a high count of males, others a high count of females...Though I was very pleased with my Anery Stripe clutch which provided a perfect 50/50 split of sexes.

Due to this years results, I do not think cornsnake sex is at all related to temperature.

 

[PtDnsr]

Hence why I'm saying my experience is limited. And like I said, it could be that Murphy is being nice. I did notice that the past two years we were very female heavy (one clutch was 1 male and 12 females!). At least for the time being, I will go with right now from what we know they're not temperature dependent.

~Katie

 

[MegF.]

I think Stephen has found that when he incubates at a lower temperature he gets more females. I found that to be true with my first clutch also. Out of the 21 babies, 12 were female. I incubated around 80 degrees, and Stephen kept them at my house and incubated them at room temp (low 80's) also. I don't know what his female to male ratio was on these 6 clutches.

 

[gnarhimself]

Thanks for your replies everyone. :cheers:

 

[TripleMoonsExotic]

I think Stephen has found that when he incubates at a lower temperature he gets more females. I found that to be true with my first clutch also. Out of the 21 babies, 12 were female. I incubated around 80 degrees, and Stephen kept them at my house and incubated them at room temp (low 80's) also. I don't know what his female to male ratio was on these 6 clutches.

I incubated 9 clutches (close to 100 offspring) at 82 degrees.

Clutch # 2006.001
3.4

Clutch # 2006.002
11.8

Clutch # 2006.003
2.0

Clutch # 2006.004
3.6

Clutch # 2006.005
4.6

Clutch #2006.006
3.3

Clutch #2006.007
5.4

Clutch #2006.008
2.9

Clutch #2006.009
9.6

TOTAL:
42.46

Definitely not temperature sex dependent.

 

[stephen]

I think temps do influence sex ratios

In my experience the higher the temps the more males hatch out

 

[Serpwidgets]

From the little bit of info I was able to find about this (not about corns specifically) it's apparently possible for incubation temps to affect gender in some species that DO have sex chromosomes. Corns do have sex chromosomes (male = ZZ female = Zw) so I would think this could get weird.

(IF it's even possible...)

If you can produce a Zw male, if it's fertile, you breed it to a Zw female, and the outcome would be 25% ZZ males, 50% Zw females, and 25% ww which would be incompatible with life. So you might be able to make a male that produces twice as many females as males (but has a 25% lower fertility rate.)

If you produce a ZZ female and breed it to a ZZ male, there's no w chromosome and therefore (unless incubation temps are used once again to override the sex chromosomes) the entire clutch would always hatch out male. You could end up with females that are incapable of producing genetic female offspring.

Anyway, I guess my point is that if it's possible to use temps to influence gender ratios in your clutches, I personally wouldn't want to do that anyway, since it would basically "pay you back" when you try to breed the next generation.

I would still be interesting to see two halves of the same clutches incubated at different temps to find out if it really is happening.

 

[TripleMoonsExotic]

From the little bit of info I was able to find about this (not about corns specifically) it's apparently possible for incubation temps to affect gender in some species that DO have sex chromosomes.

Yup, their are a few that are temperature sex dependent (Leos, Fat Tails, Crocs, Alligators...)

79-84 most will be females
85-88 almost an equal number of males and females
89-92F most will be males

Of course the above will vary slightly, and is not 100% accurate.

Anyway, per the number we follow for Leos, my Cornsnake incubation temperature should have yielded a high count of females, and it didn't. Which is why I don't believe Cornsnakes are TSD. I don't believe ANY snake has been proven TSD. I think it's just wishful thinking when some people get good or bad odds.

 

[stephen]

Well

Well you incubated them right in the middle,they can be incubated at higher and lower temps,so that being said it isnt unsual for a mix of sexes

 

[TripleMoonsExotic]

No, I incubated mine at 82 degrees, which if TSD was true for cornsnakes, would yield more females. See post #9 & 12.

 

[PtDnsr]

No, I incubated mine at 82 degrees, which if TSD was true for cornsnakes, would yield more females. See post #9 & 12.

Not unless the range was different for corns. Corns have a range that extends into New Jersey so their temperature range could be lower than that of other herps. Just a possability.

~Katie

 

[Kat]

I incubated my eggs at 86 degrees this year, and got far more females than males. Every clutch this year was either equal or female-heavy.

-Kat

 

[stephen]

ummm

82 is right in the middle,eggs can be incubated between 70 to 90 degrees! Also unless you had a thermometer that is very accurate, right next to the eggs, your readings could be off a couple degrees, I am not sure if temps do determine sexes but to rule it out would be foolish IMO! :grin01:

 

[TripleMoonsExotic]

I incubated my eggs at 86 degrees this year, and got far more females than males. Every clutch this year was either equal or female-heavy.

-Kat

Kat posted another example right here disproving the wishful thinking that Cornsnakes are TSD.

High temperature would be male heavy.

I am not being foolish, I'm just not letting wishful thinking get in the way of hard proof. Their is definitely no "maybe" when considering TSD. Low temperatures result in 85-95% female, high temperatures result in 85-95% male.

 

[venomstreet]

I'm new to Corns, but not new to snakes. The first clutch I ever hatched out were Common Brown Snakes. Since then I've bred mainly Cobras, and incubation temps definitely do have an effect on snakes. I got 80% males at 85 - 86 degrees, and my buddy got about 65% females at 80 - 84 degrees. True the snakes are not the same snakes, but a buddy of mine that is a Corn breeder, and I'd bet most all of you know him. He hatched out more females this year at 84 degrees than he did in years past with the same pairings, at 85 degrees.
Blckkat should make the exact same breedings this year, incubate at 85 degrees and see what the results are, as compared to the results in the last post. I'd bet money more males are hatched out on average.

RC

 

[TripleMoonsExotic]

Please explain then Kat's female heavy clutch incubated at 86 degrees.

Like I said, TSD is much more strict. 85-95% of a single clutch would would be male or female heavy. I dealt with 9 different clutches which averaged at 50/50. BUT Clutch #2006.002 (11.8) was male heavy, while Clutch #2006.008 (2.9) was female heavy. Two different clutches, incubated at the same temperature with completely opposite results.