Reptile & Amphibian Forums

My knowledge on breeding snake is very limited likewise for genetics. Currently, my BP is a pet and not a breeding project for i still have much to learn.

PLEASE NOTE, this question is out of curiousness.
(IT IS BY NO MEANS TO AFFEND ANYONE!!!)

Now,
I hear speaking of line breeding, mothers with son, fathers with daughters,... doesnt that type of inbreeding affect the genetic pool and the babies health(deformities, disorders) OR is that not the case for reptiles?

Thanks for any responce,
PB

All inbreeding does (in any living thing) is increase homozygosity. That is, it increases the chances of like alleles being paired up. Sometimes that results in lethal recessive alleles being expressed, but we're talking wild animals that have evolved for millions of years. Their genes are pretty set and there likely isn't many lethal alleles floating around in their gene pools.

Please note the 'bug eye' deformity in Texas ratsnakes, which is 'linked' with the leucisitc gene.
On the other hand, bearded dragons have an extremely small gene pool but no bad mutations have sprung up.
So, I guess agreeing with the other post, inbreeding will bring any recessive genes to the forefront, but if the genes don't exsist in the first place, then nothing bad will happen.
Of course, we technically could count most color mutations such as albino as detrimental mutations, as they would affect the ability of snakes to survive in the wild.

Your description of genes being 'set' is innacurate. You have to appreciate that in any gene pool there is a huge number of 'bad' genes knocking around. This is why so many (relatively) albinos, leucistics etc pop up. These are genes that would more than likely prove lethal to a particular animal, just as a mutation giving the snake no eyes would.

Anyway, I won't go too far into it, but suffice it to say inbreeding will lead to the eventual expression of these 'bad' genes. In some cases (when people are hoping for unusual colour / pattern mutations) this can be a good thing, but in others it will lead to reduced reproductive success etc.. The question is, how much inbreeding can you do before such mutations begin to surface. If you have access to a copy of the Reproductive Husbandry of Pythons and Boas (Ross & Marzec) this is described very well.

In some cases, such as island (or highly localised) populations, many of the deleterous genes have already been eliminated from the population, simply because the population size is so small. Then, you may get the 'setting' of genes Jeff describes, although there's still going to be some genetic diversity present.

I should also say that snake breeders, well ball breeders especially, are in some way avoiding inbreeding depression, through the production of hets. The use of wild blood to cross with all morphs to produce hets 'injects' fresh genetic diversity into the captive population. That is why one should always think about having 'normals' in the collection, and keep outbreeding the morphs.

It may be easy to say now that inbreeding isn't having any effect, but what about in ten years? Keep them hets coming!

Good question. I know corn snake breeders have inbreed for many generations and some claim it doesn't matter. In my limited experience though, some of my better corn snakes where the most outbred ones. The bloodred line was one that was suspected to suffer ill effects from too much inbreeding but I had some really nice outbred bloodred X blizzards. Some claimed it was just the nature of the bloodred line to be small and want to start on lizards based on where they came from though. I haven't really kept up on corn snakes but last I knew there where lots of people outbreeding some of the inbreed lines that where suspected to have some problems due to inbreeding.

I've heard that boids may be more at risk for inbreeding problems quicker. I don't know if enough boid breeding has been done (compared to corn snakes) to really be scientific about this but it seems that eye problems popped up fairly quickly in albino burmese pythons, albino boas, and I even read recently about an albino olive python I think it was. At any rate, boid breeders seem to work harder to not inbreed any more than necessary so I think we will be ok. Often inbreeding is done for one generation and then outbreed the next with ball pythons (while corn breeders might line breed 7 generations or more). There is also a lot of new blood coming into the captive ball python population every year.

It will be interesting to see if we start seeing ill effects as morph combinations become more commonplace. With the 1 in 16 hit of outbreeding a double recessive trait it will be harder to do than the 1 in 4 of a single recessive trait. I suppose breeders can outbreed to unrelated morphs of one of the genes in the combo and not have to work as hard to get the combo back (i.e. Ralph might breed his snow males to unrelated axanthic and imported albinos). Also, with the prices of double hets being so high there are lots of different people making the initial crosses now so it should be possible for breeders to find unrelated morph combos for a while.

....and these are still more reasons why.................................ball pythons RULE!!!!
SJM

I prefer boas. Hahahaa.
I found you, Scott.

Hey Brett!