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Discussion Starter · #1 ·
So I have been thinking about this a lot recently, many of you will know my thoughts on the matter, but I want to hear the thoughts of those that choose to breed, lets call them: non-perfect animals (as deformed may be misleading in some cases).

There are a great number of cases every year, over a range of species where non-perfect animals are produced. I'm talking about minor things such as tail abnormalities in leopard geckos, eye abnormalities in various species, through to medium and more severe deformities such as six toed crested geckos and even limbs missing in certain species.

For those who have animals like this, and have considered breeding them, or have bred them, what is your rationale?

I don't want this to descend into an argument, or to be simply a thread saying "I wouldn't do it!". I really want to know why people do it (as it is their choice).

Andy
 

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I think some would breed deformaties, or imperfections because some would consider them cute, if there is a market for things that pull the heart strings of sympathy, they are more likely to be sold, not always first but if you can band up a story suited or fitting to the animal to give it the "Aww" factor then some will do it. Something I struggle to see the logic of, as there may possibly, just possibly be underlaying or invisible problems linked to this sort of breeding, hear defects and what not, though some are perfectly normal just a few abnormalities.

I wouldnt advise this sort of breeding, if it happens due to natural causes then so be it, but not by selectively breeding animals to get this to happen.
 

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Discussion Starter · #4 ·
Hey Toyah,

This is an interesting question. Firstly I'm unsure as to whether we can consider it as polydactyly in this species, I don't know enough about it in all honesty. In other species it is autosomal dominant, but I cannot be sure that this is the case here.

Having only seen pictures of affected animals, I really can't comment on whether they are disabled in any way, but I know there are people on here that do own some, so perhaps they could answer with first hand experience.

Andy
 

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I personally will not breed any geckos who were born with a deformity. For instance, I had 2 geckos born 3-4 months ago and the male is perfect, has absolutely no deformities or health problems, but the clutch mate, a female, has a slight under bite, not severe, but enough that if you look at her you can see it. When she was born she was instantly a 'Pet only-Not for breeding' gecko. But I see a lot of other people breeding and encouraging these deformities as though it is a morph. Some other people breed their deformed animals because they want to have baby geckos, but don't want to have to buy new geckos that don't have any problems.
 

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I wouldn't breed a gecko if it wasn't perfect, i've taken in a few leos with abnormalities and although they live happily as pets I don't think its worth the risk to breed potentially disabled reptiles. Some may not be lucky enough to find homes as pets or may be bred from which just perpetuates the problem.
 

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I think that the gene pool for certainly some lizards bred in captivity is very small. For that reason I feel it is up to breeders to only breed from the strongest specimens possible to try to prevent genetic abnormalities becoming the norm. As far as non-genetic abnormalities I still would not breed, as has been said by cazzie, you never know if there are also invisible internal deformities.
 

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Discussion Starter · #8 ·
Hi guys,

Thanks for your replies. As I said, I'm not really looking for people saying they wouldn't breed non-perfect animals, but rather people who WOULD or HAVE bred them, and the reasons they do.

There are a variety of reasons why I would not advise it, but arguably some mutations could have positive fitness attributes. It can be difficult sometimes to suggest reduced fitness for certain characters.

Andy
 

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I don't see the purpose in producing deformed animals knowingly and on purpose.. your only going to cause more harm than good IMO. To the animals and the market.
 

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I would absolutely never continue to breed if a disabling feature occured. However in scientific studies I can see why breeding to work out what is going on might be worthwhile.

I can only really comment on personal experience about crested geckos.



I would be more concerned with what the trait could potray under the visuals. It may be nothing but since I prefer to err on the side f caution I think if for example any of my hatchlings were born 6 toed I would destroy the rest of the eggs from those parents and retire the parents.

A disabling trait is simply not as simple as a visual.. somethinjg may look fine and not cause outward issues but its what is going on genetically. Who knows in a few generations if further mutated genes will cause more issues that stem from the 6 toe trait in crested geckos.
 

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Discussion Starter · #11 ·
Just to clear a point up:

IF six-toed crested geckos do represent polydactyly, and is indeed autosomal dominant then ALL carriers will present the six-toed phenotype. This means that it will be obvious which parent is the carrier.

I would not breed them again, BUT I would also NOT destroy the eggs, as you have no way of telling whether the carrier parent is homozygous or heterozygous, meaning there is no guarantee all offspring will carry the mutation.

Andy
 

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Not that I would breed abnormalities myself, there is a question to be considered. Are you/ we being a hypocrite’s if we own/ breed any sort of human modified species such as a dog? Considering not one breed of dog around today exists due to nature, but instead human controlled (and please don’t say, people never meant to let them breed) selective breeding for various traits to create working animals to better our lives (e.g. collies) or the more recent fashion breeding (e.g. pugs).
The other thought that I might ask to be considered is; if you were to pretend that a particular species has become extinct or becoming so in its natural environment (I do realise there are many species that fit that grouping), how can we be sure that these so called “abnormalities” in captivity is not the species slowly evolving due to the probable fact that almost all captive animals are not kept in conditions that are at least 70% environmentally similar to there natural environment.
 

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Discussion Starter · #13 ·
The other thought that I might ask to be considered is; if you were to pretend that a particular species has become extinct or becoming so in its natural environment (I do realise there are many species that fit that grouping), how can we be sure that these so called “abnormalities” in captivity is not the species slowly evolving due to the probable fact that almost all captive animals are not kept in conditions that are at least 70% environmentally similar to there natural environment.
You make a good point, however we are considering reduced fitness characters, and not true selection, which is something a little different. You can select abnormalities IF there is no associated reduced fitness, but if there is selection will intensify it.

Andy
 

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Not that I would breed abnormalities myself, there is a question to be considered. Are you/ we being a hypocrite’s if we own/ breed any sort of human modified species such as a dog? Considering not one breed of dog around today exists due to nature, but instead human controlled (and please don’t say, people never meant to let them breed) selective breeding for various traits to create working animals to better our lives (e.g. collies) or the more recent fashion breeding (e.g. pugs).
The other thought that I might ask to be considered is; if you were to pretend that a particular species has become extinct or becoming so in its natural environment (I do realise there are many species that fit that grouping), how can we be sure that these so called “abnormalities” in captivity is not the species slowly evolving due to the probable fact that almost all captive animals are not kept in conditions that are at least 70% environmentally similar to there natural environment.

this is a very good point!



Another thing is environmental affects, i.e. temp change in eggs producing a deformed baby, would you then not breed that pair again?

Its difficult to say really.


I would like to try and learn more about the 6toe crestie problem (can we call it a problem) What if its evolution?

Should we be the ones to decide to stop it just because something doesnt look right?

Obviously deformities like missing legs (I have a beardie missing a 'leg' kinda just has a big odd claw thing, still movable and usable to an extent) i wouldnt breed from.

But again, I suppose it depends if the abnormality is an actual issue or not ^^
 

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You make a good point, however we are considering reduced fitness characters, and not true selection, which is something a little different. You can select abnormalities IF there is no associated reduced fitness, but if there is selection will intensify it.

Andy

To be fair, you could say that with great danes, We have bred them to be very large and so they suffer from heart problems and a shortened life span.

Same with cavilier king charles spaniels, they can have alot of brain and eye problems
 

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Just to clear a point up:

IF six-toed crested geckos do represent polydactyly, and is indeed autosomal dominant then ALL carriers will present the six-toed phenotype. This means that it will be obvious which parent is the carrier.

I would not breed them again, BUT I would also NOT destroy the eggs, as you have no way of telling whether the carrier parent is homozygous or heterozygous, meaning there is no guarantee all offspring will carry the mutation.

Andy

Andy, I believe that people are producing 6 toed geckos from perfectly normal looking adults, meaning it must be a recessive trait. I think that from the larger american rhac forums, this has been the case several times..

But, where do you draw the line? Say you had a proven pair of 5 years, numerous babies have been produced, all normal, and one day, a 6 toed gecko is born.... would you retire the parents due to this or chalk it up to a random mutation in that particular animal? If it was regularly happening in say 1 in 4 eggs, then that would be a more clear case of both parents being carriers and those should be retired.

I suppose though, in order to understand the impact of this mutation, then it needs to be studied more, but that would undoubtedly require much money, time and breeding of these geckos. I do not believe that any of the ones I have seen are disabled by the extra toes, more that they are little nubbins attached to a toe. I don't think it looks like polydactyly to me, as I work in a genetics lab who study human polydactyly (and they all seem to have functional extra digits, with bones etc)...I don't think these geckos have a bone structure in the extra digit, and I don't think they are functional at all.
 

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This is a really interesting question. I have bred sime pictus geckos & a small % of the offspring have had a minor kink in the tip of their tail - I'm keeping these individuals & all the healthy lookng offspring will be sold with the caveat that they arent bred - the adults will not be bred again.

While we are on this subject what do people think about breeding of pedigree cats & dogs? Some of these animals are deliberatley bred for their deformities (& these are seen as desierable!) In the reptile hobby we routinely breed for deformities whether we like to believe it or not - albino, hypo, superkiller - bumblebee - mojave glow in the dark morph etc (an exaggeration but you get my idea). The morphs we create generate novelty but they also concerntrate genes which in all likelyhood would not survive in nature - the reason they wouldnt survive isnt always that they stand out - it may be due to the fact that the animal is of suboptimum health in one way or another. For example royals, I imagine that an albino royal would not be predated on in nature due to the fact that these animals spend almost all their lives in a burrow & only come out at night when being white would not make a huge difference becaue its dark - so why arent there more wild caught albino royals? The genes for this exist in the wild as thats where we found one, i suspect that its due to something else to do with health/behaviour etc.

I know that I have come across as very anti the breeding of animals with deformities but I do want to spend a moment thinking about the flip side - although natural selection favours survival of the fittest/most adapted some of the 'sub-prime' animals will invariably get to breed & these individuals do contribute to the species overall genetic diversity & may even lead to new species/subspecies if the conditions are right.

As always theres two sides to any argument but for my money only breeding the best/fittest & most genetically diverse group of animals is the way forward

Thanks
Ben
P.S sorry about my typing tonight - spelling mistakes abound I'm sure :)
 

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i personally wouldnt breed from `deformed` animals,

i do think that breeders blame `fluctuating incubation temperatures` for deformaties a little bit too readily.

theres a hell of a lot of leos around with eyelid problems and inc.temps are always blamed.
 

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Just to clear a point up:

IF six-toed crested geckos do represent polydactyly, and is indeed autosomal dominant then ALL carriers will present the six-toed phenotype. This means that it will be obvious which parent is the carrier.

I would not breed them again, BUT I would also NOT destroy the eggs, as you have no way of telling whether the carrier parent is homozygous or heterozygous, meaning there is no guarantee all offspring will carry the mutation.

Andy
So basically, it's a game of wait and see. I have to say, if anything looked abnormal to one of my hatchlings, first thing I would do would start researching, and looking into why it may have happened.

I have to say, I am with Andy here, I really want to hear from some of the people who have experienced the "six toed" gecko and hear their opinions.

how can we be sure that these so called “abnormalities” in captivity is not the species slowly evolving due to the probable fact that almost all captive animals are not kept in conditions that are at least 70% environmentally similar to there natural environment.
Fantastic point. I see how being kept in a stable environment, temps/regular food/water etc, being a key point into this.

One thing that springs to mind is, in the wild, they have no glass. Just trees.

The majority of us keep crested geckos in glass vivariums, as much as I am all "for" stopping the six toed mutation, I am not so narrowminded as to think it may well be a part of a probable evolution.

I like that theory. But I still believe that the six toes is a sign of trouble ahead, until factually proven wrong.

Andy, I believe that people are producing 6 toed geckos from perfectly normal looking adults, meaning it must be a recessive trait. I think that from the larger american rhac forums, this has been the case several times..

But, where do you draw the line? Say you had a proven pair of 5 years, numerous babies have been produced, all normal, and one day, a 6 toed gecko is born.... would you retire the parents due to this or chalk it up to a random mutation in that particular animal? If it was regularly happening in say 1 in 4 eggs, then that would be a more clear case of both parents being carriers and those should be retired.

I suppose though, in order to understand the impact of this mutation, then it needs to be studied more, but that would undoubtedly require much money, time and breeding of these geckos. I do not believe that any of the ones I have seen are disabled by the extra toes, more that they are little nubbins attached to a toe. I don't think it looks like polydactyly to me, as I work in a genetics lab who study human polydactyly (and they all seem to have functional extra digits, with bones etc)...I don't think these geckos have a bone structure in the extra digit, and I don't think they are functional at all.
I think there is a big difference between a nubbin and a sixth toe. Some crested geckos I have seen, their six toe is nearly the size of one of their others.

I am in no place to say it's bad or not, but based on some digging, and reading, research and help, I really do believe it's not for the good and it's something that needs to be kept watch upon.

I also believe that if it is proven to be an evolutionary trait, as I stated before, then it would make sense to me, but until it's all tested, researched and factual, I stand by and say it can't be good.

Yet, I come to the conclusion, reading of some people, like you have stated, breed a pair for five years, then out comes a six toed gecko? The explanation for this would surely be an evolutionary one....

I need to go and study a bit more on genetics :blush:

While we are on this subject what do people think about breeding of pedigree cats & dogs? Some of these animals are deliberatley bred for their deformities (& these are seen as desierable!) In the reptile hobby we routinely breed for deformities whether we like to believe it or not - albino, hypo, superkiller - bumblebee - mojave glow in the dark morph etc (an exaggeration but you get my idea). The morphs we create generate novelty but they also concerntrate genes which in all likelyhood would not survive in nature - the reason they wouldnt survive isnt always that they stand out - it may be due to the fact that the animal is of suboptimum health in one way or another. For example royals, I imagine that an albino royal would not be predated on in nature due to the fact that these animals spend almost all their lives in a burrow & only come out at night when being white would not make a huge difference becaue its dark - so why arent there more wild caught albino royals? The genes for this exist in the wild as thats where we found one, i suspect that its due to something else to do with health/behaviour etc.

I know that I have come across as very anti the breeding of animals with deformities but I do want to spend a moment thinking about the flip side - although natural selection favours survival of the fittest/most adapted some of the 'sub-prime' animals will invariably get to breed & these individuals do contribute to the species overall genetic diversity & may even lead to new species/subspecies if the conditions are right.

As always theres two sides to any argument but for my money only breeding the best/fittest & most genetically diverse group of animals is the way forward

Thanks
Ben
P.S sorry about my typing tonight - spelling mistakes abound I'm sure :)
Good points here, selective breeding for positive traits, healthy traits, surely this still has it's downfalls? Either way, it will continue, whether it be crested geckos, dogs or horses.

I just believe that if something occurs that doesn't seem right, precautions should be taken to stop any further "occurences" that may alter the gene pool, as already, line breeding has taken it's toll..

Again, off to read up on more genetics :blush:

Really good topic...

Hoping to hear from some others about this.

Jac
 
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