Reptile & Amphibian Forums

So I spoke to customer service at Zoogen (the Parrot DNA sexing company) today. They offer DNA (blood sexing) of the green iguana. They also have blood sexing of komodo dragons.... (I think the dragon sexing is someone's current research project). They CANNOT DNA sex other reptiles currently, though it would be very possible if there was funding and interest for the company to do the research- ie the technology exists- it would be the same as sexing the iguana or k dragon, but they don't have the data (yet) to have any results be meaningful. So we with skinks will need to continue to employ other methods such as behavior, width ratios ect.
Cheers, Jess b

SOUTHERN FLORIDA CORUCIA RESEARCH CENTER (SFCRC)

Location: LEE/1.

Hi Jess,

Thank you for for posting this and researching it. As far as the interest and research to set this up, this is still another reason for 'Corucians' to coordinate with each other in some sort of group action and work to achieve this. As Breeders and Guardians of this species- this needs to be one of our goals.

How are you feeling these days? Are you getting advice from Gertie? LoL.

Hope the babies are fairing well.

Sincerely,
Brian
SFCRC

I assume this can only be done with species that have genetically determined sex?

Brian

I have never heard of any commonly kept reptiles whose sex is not determined by genetics.
For what it's worth, I know of some species of small lizards in which all members are female, but even that is genetically determined.
I'm not trying to be a smartaleck, but I'm just wondering how else an animal's sex would be determined if not by its genetic makeup. Maybe I misread the previous post.
Thanks.
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Edward
Carpe diem

Reptiles may reproduce in of three ways (that we're currently aware of).

The first is sexual reproduction with genetic sex determination. This is the form of reproduction that most people are used to, as it's the form that humans employ. A quick review: Human females have 2 X chromosomes, human males have an X and a Y. Each parent gives one chromosome to the offspring. The female always gives an X, the male can donate either, and thus determines the gender of the offspring. Snakes are exactly the opposite. The male has two Z chromosomes, and the female has one Z and one W, thus determines the sex of the offspring. This will be important later.

The second form of reproduction is sexual reproduction with environmentally determined sex determination (ESD). This is the type that the poster was probably refering to. Typically this means temperature dependent sex determination (TSD), which means that the temperature at which the egg is incubated determines the gender of the offspring. This is the case for all crocodilians, many turtles and tortoises and some geckos (like the leopard gecko). There is also increasing evidence that the presence of PCBs may influence sex determination by acting as an estrogen.

The last form of reproduction is asexual parthenogenesis. In this case a female snake or lizard gives birth without male input. Most herp folks have heard about female colonies of fence lizards that reproduce in this manner. The interesting thing is that there are several species of snakes that typically reproduce sexually that have recently been discovered to also reproduce parthenogenically (including the timber rattlesnake - Crotalus horridus). In these snakes the offspring have all been male (remember, female snakes are WZ). Earlier this year a Burmese Python in Holland was the first boid with verified parthenogenic reproduction. Her offspring was a female.

I know this is bit more than you were asking for, but it's pretty darn cool and I just couldn't help myself.

-Z

n/p
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Edward
Carpe diem

Very good info and well written- thanks!

Does this take place with NO male involvment EVER...or as happens with veiled chameleons, where the female will mate with a male, produce a clutch of eggs...then at a later date produce MORE fertile eggs from retained sperm, without actually mating a second time?

Sorry if it's a stupid question, I'm just struggling with the idea of any species being able to give birth, with NO male involvement whatsoever.

Thanks...
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Kim

I agree that it sounds incredible, but that is the case.
Here's a link to a paper on the subject in the context of whiptail lizards. It's a little technical but helpful nonetheless.

Parthenogenesis in whiptail lizards
Link

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Edward
Carpe diem

The most famous snake to do this is the flowerpot snake or Brahminy blindsnake. No males of that species have ever been found. Pretty cool! And I saw that parthenogenic timber on TV, that was strange too.
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Peter: It's OK, I'll handle it. I read a book about something like this.
Brian: Are you sure it was a book? Are you sure it wasn't NOTHING?