Reptile & Amphibian Forums

My observation with a few clutches of acanthosaura and gonocephalus, has revealed a much higher number of females per clutch, this leads me to believe they are genetically programmed to produce females.
This would avoid territoriality and assure a more reliable propagation of the specie, in theory?

Exact measurements showed males to have 1/3 longer tails then females, on this photo of siblings, both males are quit obvious, even on this low resolution pic.

Cute babies. I have to go look at mine noe.
I do enjoy reading yours and Ingo's posts. Have you ever tried to produce a specific color capra? I like the reds or greens. A few of my babies have green on their lower face and neck already but I know that doesn't mean much.

Thank you very much!

Me I enjoy when you guys show interest, without your participation posting would be quit boring, of course studying the animals is never boring.

I just started working with these lizards, didn’t even have time to grow them to adulthood yet, therefore I am still far from selective breeding.

However I know from experience with other species that the possibilities for color morphs are endless, and just between us I am raising one gono that hatched completely yellow. Sorry I hope you understand that I have projects for this lizard and will not show it just yet. Telling so you know anything is possible.

Ps, let me know about the sexing.

Hi,

its defintiely true, that male hatchlings do have longer tails, even though in my animals that difference was less pronounced.
I was always assuming that Gonocephalus and Acanthosaura sex is influenced by TDSD with more females at low temps, more males at higher temps and like 100% females if you keep eggs at 29 ° between week 3 ad 5 (if kept constantly at 29° for the full incubation time, hatching rates are very low)
But my statistics are not copious enough to be sure and since some time I am (almost) out of these lizards.

Ci@o

Ingo

Ingo, If you are right then what the heck am I doing wrong? I am incubating at 65-72 and seem to be getting more males than females. This is very frustrating as I really need some females!
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Marcia - FroggieB Dragons
www.froggieb.com/MHDHome.html

Just looking at them in the tank it seems like I have alot of males. I kept temps as close to 70 as possible myself.

I really don’t know about the TSD possibilities in gonocephalus and acathosaura species, I have not hatched enough to witness any indication leading to TSD.

However in my opinion the incubation of these species should never be at a constant temperature, the hatchlings on my photo where incubated in the 75f (24c) to 86f (30c) range and hatched at 76 days. I did not aim for a shorter incubation, but was only experimenting the possibilities. I have no intent to hatch them out like pop-corn, my goal is to maximise there inherited development potential.
From my observations of captive lizards and natural habitat, I am now starting to see a pattern of there nesting biology. Until farther observation this must be considered deductive. So pleas be open minded and allow me room for error, nothing is set in stone and this may change eventually, at least to some degree.
I believe these lizards will nest in locations where the sun will hit the grown at least part of the day (1-2-3h??) this allowing a significant raise in temperature 85f-95f easy, the nest slowly lowering temperature to the usual NTL 68f-77f (my case 75f)
This short heat up is important for development, it works in many ways!
First heat accelerate the metabolism of the embryo, this leads to absorption of the yolk witch in turns allows growth of the embryo. Next heat lowers the atmospheric pressure on the eggs, this also allows growth and movement of the embryo, furthermore the relief of atmospheric pressure allows the egg shell to grow, Last a lower pressure allows your eggs to hatch, imagine a baby lizard trying to force its way out when pressure from the outside is working against him, lowering this pressure allows the baby to push it’s way out with little force. Saving energy is vital.
This is why in nature eggs hatch in the rainy season, when low pressure fronts.
Now we as keepers can offer this option to our captives, and never again experience with week babies or fully developed dead embryo, in time I will show you a very simple way of doing this. Meanwhile I have much more to study and experiment.
I hope this was clear for all

This is an amazing find if true. I will have an incubator deticated to this concept, and will try it on some of my dragons and cyrtodactylus.