Reptile & Amphibian Forums

Hi all,

Was just wondering. Have heard alot about birth defects in hatchling geckos on the forums lately and was wondering if these tend to be genetic issues vs environmental (i.e. cold incubation temps, too most or too dry, etc).

It seems to me that given all the morphs and the degree of inbreeding that is done to enhance a particular strain that there may be tendencies for genetic defects to be passed along as well. Granted, top breeders are likely to do what they can to reduce this problem with their breeding programs through careful selection.

Does anybody have experience to speak from as to the number of birth defects that might be considered "normal" among a population of say 100 hatchlings?

I've not started any gecko breeding programs. Not sure I want to other than to sustain my own supply of pets any time down the road (which again seems unlikely given the number of clutches from a single mating and what I'm prepared to keep).

N.F.

I would say it is very low. Some are genetic, but others maybe due to environmental conditions such as unstable incubation temps.

What I would recomend is if you have a group that put out defected offspring fairly regular, I would not breed them, and warn anyone that bought offspring not to bred them either.

You said..."Have heard alot about birth defects in hatchling geckos on the forums lately and was wondering if these tend to be genetic issues vs environmental (i.e. cold incubation temps, too most or too dry, etc)"...I have bred leos and several other species of geckos for years and have never had a birth defect.

As far as defects go...in all my years of hatching lizards...I have only had two defects show up.
I have had a water dragon born with a cleft palate...don't know what would have caused it. Cleft palates might be genetic. I had a chameleon (first one I ever hatched) born with a light bend in the spine...I'm sure it was from incubating at too high a temperature.

I also have been looking after a uromastyx that has part of its two back legs missing and has stunted growth....I'm reasonably sure that this was related to the incubation too.

You said..."It seems to me that given all the morphs and the degree of inbreeding that is done to enhance a particular strain that there may be tendencies for genetic defects to be passed along as well"...here's an article that talks about inbreeding (not about geckos) that has some interesting information in it...
http://www.petsmart.com/global/articles/article_detail.jsp?CONTENTcnt_id=10134198673267876&FOLDERfolder_id=9852723696503980&N=228

One more...
http://query.nytimes.com/gst/fullpage.html?sec=health&res=9E0CEEDF1030F933A25752C1A964958260
"Inbreeding is thought to be harmful to a species for two reasons: first, because it allows hazardous recessive traits that are normally in the genetic background to come to the fore, resulting in birth defects, stillbirths and in some cases infertility; and second, because it leads to a genetically uniform population without the diversity to resist epidemics and environmental changes. But the San Diego scientists said their cheetahs almost never bore defective cubs, were perfectly fertile and had great variation in their immune systems."

And more again...
http://www.wolfweb.com.au/acd/birthdefects.htm
"POTENTIAL CAUSES OF BIRTH DFECTS: Heredity. Adverse chemical or physical agents, infections and inappropriate nutririon can all result in birth defects."

Here's one that shows a different result...
http://www.bigcatrescue.org/white_tigers.htm

Please be aware of the sources of the above sites when you decide their validity.

Hope this helps.

Thanks! That's good to know. I'll look through the sources you've posted. Perhaps I've gotten an exaggerated perception because it's less likely (or memorable) to hear about the normal hatchlings on the forums.

v/r,

N.F.