Question: Which factors determine gender on caudates?

[OZIRIS]

Hello,

I was wondering which factors are linked to the gender of juvies. Maybe water temperature? or weather temp while they are growing in the eggs? (like crocs?), water quemistry? or is it aleatory and the percent can vary?

anybody knows?

Regards

 

[Nathan]

Sex determination in salamanders is genetically controlled, as in birds and mammals, not environmentally controlled, as in many reptiles.

However, some conditions, including hormone treatments or extreme temperatures during larval development, can cause sex reversal. Unlike humans, "neomale" (masculinized, genetically female) individuals of some salamanders (such as P. waltl) can produce viable sperm and fertilize the eggs of another female.

Read more here: http://www.springerlink.com/content/nxy0q1wyqjehhcem/fulltext.pdf

 

[OZIRIS]

Interesting, for a moment I believed it could be controled by temperature due to their style of life very close to water.

So, Is 1:1 a normal sex ratio for C.orientalis ?

 

[Nathan]

I would assume so, unless there is a confounding factor (such as a greater likelihood of one sex to die pre-hatching).

 

[SludgeMunkey]

I seem to remember reading somewhere (possibly even here on the forums) that just recently a link between temperature and sex ration had been discovered in a species or two of North American caudates. However, as far as I have read, other than external environmental effects such as pharmaceutical or certain herbicide pollutions, sex ratios are the standard genetic 50/50 chance.
I am a bit short on sleep at the moment, but I will dig through my archive hardrive tomorrow and see if I can dig up the papers I have on the subject. I am ceratin I saved them somewhere.

 

[Jennewt]

There is also a decent description of amphibian sex determination in this book:
http://www.caudata.org/forum/f1-gen...book-review-amphibians-hofrichter-editor.html