Does Temperature effect Tarantula sex?

AmbushArachnids

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I had a friend interested in my tarantulas. He had brought up that alligators that are in kept warmer will have more males or turn out to be males after they are hatched. I dont know that there is any truth to this and am very skeptical. But i thought this would be an interesting subject. any thoughts?
 

Stan Schultz

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I had a friend interested in my tarantulas. He had brought up that alligators that are in kept warmer will have more males or turn out to be males after they are hatched. I dont know that there is any truth to this and am very skeptical. But i thought this would be an interesting subject. any thoughts?
This question has popped up from time to time over the years, and the truthful answer is that we don't know for sure. At best, the general feeling is that temperature has little or no effect, but there are lots of times when enthusiasts have received shipments of 6, 8, or 12 spiderlings of a given species (presumably from the same eggsac), raised them to maturity, and found that they're almost all male or all female. Is this just accident, or is there a good reason?

As far as I know, no one has yet taken the eggs from an eggsac, divided them into batches, incubated each batch at a different temperature, then raised the babies through enough molts so that their sex could be determined from their exuvia with any accuracy.

This sounds like a GREAT science fair project because some species of tarantula (e.g., B. albopilosum, the curlyhair) breed fairly readily in captivity, produce eggsacs with large numbers of eggs, and grow reasonably fast.

For instance, one could mate a pair of B. albopilosum in the fall, between October and December. The eggsac would be produced the following spring, perhaps in April or May, and the babies would emerge in late June or July. Thereafter, with a little power feeding, the spiderlings' sex should be easily discernible from their exuvia with a dissecting microscope by November or December, a year after the project was started.

The results could then be submitted in a paper to the American Tarantula Society's Forum Magazine within a month or two, and we could all be reading about it by the following summer.

The next step, of course, would be doing it with species of several different subfamilies as a comparative study.

I can see Nobel Prize on the horizon in this one. At least a college scholarship, maybe!

Any takers? :D
 

Vespula

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Sounds like a good Idea! If given the opportunity, I'd try it.
 

AmbushArachnids

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I think It would be a great experiment. You would have to use lots of groups. A mother T kept warm after breeding along with when the eggs hatch.. one kept room temp then the eggs hatched.

then you may try 1 mother at room temp then just separate the eggs in to different climates when she dropped the sac.. And thats just controlling the temp variable. humidity would be a must for all. Then again youd have to try this with a very hardy T. Like P. murinus, Brachypelma.. It would be a very daunting experiment. It may take several tries to get everything controlled. Not to mention some Ts would have this ability when others would not. Who knows?? This is all pure speculation of course.
 

Scoolman

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I am on it. I think I would first focus only on incubating temps to see what results were produced. The next step would be to control temps for gravid females and maintain constant temps during incubation. Finaly, controll temps for gravid females and during incubation. I think would isolate any possible results to a specific variable.
I hope to be able to get a MM G pulchra to breed with my two females soon. With some luck I may be able publish confirmed resluts of the first trial by March of 2013.
Anyone want to take on another species for comparative studies of the results?
 

AmbushArachnids

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I am on it. I think I would first focus only on incubating temps to see what results were produced. The next step would be to control temps for gravid females and maintain constant temps during incubation. Finaly, controll temps for gravid females and during incubation. I think would isolate any possible results to a specific variable.
I hope to be able to get a MM G pulchra to breed with my two females soon. With some luck I may be able publish confirmed resluts of the first trial by March of 2013.
Anyone want to take on another species for comparative studies of the results?
That would be awesome schoolman. You got the idea. Thats what i was tryin to state. You would have lots of babies to take care of. It will be very exciting for you to establish realtime results since it will take so long.
 

Ryan1

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Are there any known factors that do decide or at least influence the sex of T's one way or the other?
 

AmbushArachnids

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Are there any known factors that do decide or at least influence the sex of T's one way or the other?
Not that i know of. Im sure nobody has knowledge of it if there is. There would be alot of it in breeding reports. I have not seen or heard of any discussion of any factors contributing to the gender of arachnids. Reason why i brought up the thread.
 

Scoolman

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Are there any known factors that do decide or at least influence the sex of T's one way or the other?
From what I have read about Theraphosidae so far the gender of hatch-lings is roughly 50/50. There has been no mention of any determining factors favoring one gender over another.
 

spiderworld

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I am on it. I think I would first focus only on incubating temps to see what results were produced. The next step would be to control temps for gravid females and maintain constant temps during incubation. Finaly, controll temps for gravid females and during incubation. I think would isolate any possible results to a specific variable.
I hope to be able to get a MM G pulchra to breed with my two females soon. With some luck I may be able publish confirmed resluts of the first trial by March of 2013.
Anyone want to take on another species for comparative studies of the results?
The above topic always intarested me so im trying to answer myself!


I am as we speek 1 year into my experament with the whole temp/gender thing! ive bread 2 female N Chromatus! where i kept the one female as cold as pos & the other as hot as pos! and ive also kept the same temps on the babies! ill prob start having answers in about 8 months! just to let you know avarage sise of 'hot' babies is 6cm ls! 'cold' babies 2cm!

Ill update my findings when i have some answers!
 

AmbushArachnids

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The above topic always intarested me so im trying to answer myself!


I am as we speek 1 year into my experament with the whole temp/gender thing! ive bread 2 female N Chromatus! where i kept the one female as cold as pos & the other as hot as pos! and ive also kept the same temps on the babies! ill prob start having answers in about 8 months! just to let you know avarage sise of 'hot' babies is 6cm ls! 'cold' babies 2cm!

Ill update my findings when i have some answers!
:clap:
Very good!! youve started the test before we even had the question! I call that fate{D
 

spiderworld

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:clap:
Very good!! youve started the test before we even had the question! I call that fate{D
Sweet! hope to have an accurate answer! i think i should though!
Ive done it with 100 offspring from each temp!

Cant wait till my experament starts giving answers!

Sweet! take care
 

Stan Schultz

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The above topic always intarested me so im trying to answer myself!


I am as we speek 1 year into my experament with the whole temp/gender thing! ive bread 2 female N Chromatus! ...
Great! {D

Now we need some people to try it with other species, maybe from different subfamilies. How about A. avicularia (subfamily Aviculariinae)? Not expensive, breeds well in captivity, grows fast.

Or, Pterinochilus murinus (subfamily Harpactirinae)?

Or, one of the Poecilotheria (either Selenocosmiinae or Poecilotheriinae, depending on your preference)?

All of these are common in the hobby, breed readily in captivity and are from markedly different subfamilies, giving a good cross section/comparative study.
 

spiderworld

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Great! {D

Now we need some people to try it with other species, maybe from different subfamilies. How about A. avicularia (subfamily Aviculariinae)? Not expensive, breeds well in captivity, grows fast.

Or, Pterinochilus murinus (subfamily Harpactirinae)?

Or, one of the Poecilotheria (either Selenocosmiinae or Poecilotheriinae, depending on your preference)?

All of these are common in the hobby, breed readily in captivity and are from markedly different subfamilies, giving a good cross section/comparative study.
That would be great!

To see if temps do play a role, how they differ from one subfamily to another!
Imay be breeding 2 x diff Tapinauchenius gigas females! i think that will be a great sp to have some data on! ill do it!

Cool! nice to have some interest in my work!

Take care!
 

oufbfan

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Do you think having the male in cold or hot temps before hand would play into it? I have a MF chaco In 80 and one in 70 just because my T room needs more shelves. After reading this post it got me thinking. Im about to breed them both but my male is from the 80 side. Do you think that would make a diff?
 

spiderworld

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Joined
Jul 20, 2010
Messages
90
Do you think having the male in cold or hot temps before hand would play into it? I have a MF chaco In 80 and one in 70 just because my T room needs more shelves. After reading this post it got me thinking. Im about to breed them both but my male is from the 80 side. Do you think that would make a diff?
I cant say for sure! but i highly doubt it! withmy N chromatus the two females were both mated by two diff males!

But it would be very cool if you do try follow through with the experament!

Thanx
 
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