Lets talk about hybridization.....

[Gregg M]

Difference of opinion is welcome ofcorse, but PLEASE, lets keep it civil.... We do not want this turning into a huge argument.... I am starting this thread so people can see both sides of the coin on this subject and come to their own conclusions.....

I will post the reasoning behind why I feel most hybridization should not be propagated in captivity..... Call it "idealistic nonsence" if you will, but I have pretty good reason to see fault in this part of the hobby and I stand pretty strongly by what I believe.....

So, what are we realy doing to these animals when we hybridize??? What are we doing to them on a biologic level......
I mean, some animals that are being hybridized are not even from the same evironmental conditions..... Are the hybrid offspring being torn apart inside???
Just because they appear to look normal on the outside, it does not mean everything is going well on the inside..... The proof in this is found in some hybrids..... Irregular organ placement, bone structure deformities, infertility, lung capacity issues, irregular scale formations, and neurological problems have all been noted in certain hybrids.....

There have been hybrids produced from animals that are not even in the same genus..... Animals with special organs are bred with animals lacking them..... What good can come of this for the animals "created" by hybridization???

Another thing you need to look at is the captive population.... Do you realy want tainted or unpure blood lines popping up in your collection.... People might argue that as long as they are represented correctly and truthfully by the breeder than it is fine..... I say that is nonsence.... Here is why....

Breeder A sells a super ball to breeder B....
Breeder B, breeds this snake to a pure ball.....
Babies hatch out and breeder B properly represents them and sells 4 neos to 4 other breeders/hobbiests....
Who knows what these breeders/hobbiests are doing with them or what they are breeding them to.... Even if they breed them and sell the neos as what they truely are, who is to say that every one who was sold one of these muts will represent them truthfuly if they sell them or breed them???

See how it can just get so out of hand and how these animals can make their way into a collection where they are not wanted???

But my stance does differ when it comes to natural intergrades..... Hybrids that occur in nature on a regular basis is fine in my opinion..... It is when breeders start to "Frankenstein" animals together that would never meet up or breed with eachother in their natural habitat, that it becomes a problem that can affect the animals, us, and our captive blood lines....

Look at Boas for example..... Do you know for sure you are getting a pure hog or any other sub-species??? Alot of the subs have been crossed like crazy.... Even carpets have been outcrossed to other subspecies...... I hate to say it, but even leopard gecko subspecies have been crossed so much it is absolutly impossible to get a pure subspecies now, especially because of import/export regulations.....

I feel it is highly unethical to hybridize in most cases and it does nothing good for the hobby and I find it funny when someone says it is doing something for science or taxonomy....LOL.... What a joke..... The animals do not benefit from it..... The only things to benifit from this are the hybrid breeders and their bank account....

 

[Milwaukee Reptiles]

Wow that was a hell of a post Gregg...

I tend to agree with you on basically all of those points. As for improper breeding and propogation of defects, look at tail-kinks in LVPA Leopard Geckos... It's not hybridization but it shows just how quickly defects can affect an entire market.

As for the health of animals, I don't think anyone can really dispute that there are definitly health defects that occur when hybridizing, even if it's as simple as a shorter lifespan, you may not know that until 6 years later, after you have introduced it to the amrket and sold babies, ect. And in this business, there is always someone out make a quick buck, so there will ALWAYS be mis-represented animals.

 

[JGARR]

Hi all Im not to expeirenced in this but here goes well for example what about subspecies that intergrade in the wild? it happens more than often with the box turtle species many many box turtles are seen in the wild as intergrades one in particular is commonly seen is the intergrade of 3 toed with ornate it looks like a 3 toed but with a slight pattern look of a ornate and this happens in nature and pretty much they look more unique and yet it feels that when this happens in captivity it just doesnt seem like such a negative factor personally I wouldnt do it but if I cant say that I despise others who do but I wouldnt support it either in the wild I have always wondered that intergrading probably as test in evolution in the wild but in our captivity hhmmm it just seems out of our control
thanks,
Jose

 

[Gregg M]

Good posts Brian and Jose.... This is something that is interesting to me even though I am not for it..... Maybe we can get some opinions from people that are for it as well.....

 

[DeVackHerps]

I personally, have mixed feeling about this subject. i think its cool and fascinating when i see a ball mixed with a blood, or a woma, with a carpet. but there has to be defects in it like Gregg has posted. thats what I'm not for. if its gonna hurt or make the lives of the animal hard for them. then i don't think it should be done. if its in the wild let it harpen, thats nature, but what people are trying to do is play "god". i say in captivity keep them basic, how they are. but if you buy 2 wild types that are both hybrids. then you can breed them as hybrids, because thats what happened to them in nature. but i dont think your gonna find 2 hybrids and unrealted that happned in the wild. well thats my opinion.

 

[Gregg M]

Good post Kyle....

The only thing I have to disagree with is the not finding 2 unrelated natural intergrades.... I have a few wild caught gaboonXrhino vipers that are unrelated and of different ages.... The reason I know they are unrelated is because they were collected from two different Countries in West Africa....

 

[Jim O]

As promised...

There are pros and cons with respect to hybridization and there are good reasons and bad reasons to hybridize.

Ar some level some people have a basic "emotional" response and say it should never be done. Well...never is pretty closed minded. Even the Bible, in which "Thou shalt not kill" is one of the ten biggies allows one to kill in self defense. And as I have said earlier in another thread, just because no one has seen carpondros in nature does not mean that they do not occur. Similarly for "comas" as, both cases. there is commonality of range.

Further arguing against those who oppose crosses of any kind, I do not know of any movement among equine breeders to ban the production of mules. As everyone probably knows, a mule is a horse/donkey cross, specifically a female horse with a male donkey (reversing the sexes produces the slightly different "hinny"). While it was once thought that all mules and hinnies were sterile, that is not the case. Some actually are fertile. Mules have greater load carrying and endurance capacities than horses and better temperaments than donkeys, so I understand.

People who argue that it "is not natural" may have missed the point that reptiles are wild animals and living in plastic or melamine or glass cages is hardly "natural" for them. Nor is eating "an appropriate sized rodent once a week" exactly in keeping with a "natural" feeding regimen. Nor is living on aspen or paper towels. Or drinking water from a bowl. Nor would a Ball Python from one part of its range encounter one from another, but how many here have locality data on their Ball Pythons? or their cornsnakes? How often are retics from one island locale crossed with those from others? Natural? Any of it? I think not. So the "natural argument does not hold water for me as none of how we keep our herps is all too "natural".

So when is it OK? For scientific purposes. To improve the species. To advance knowledge. And ONLY when done by reputable individuals and groups who will not misrepresent the animals or sell them to anyone who would. Hard to do, of course.

As for the Woma/Carpet cross to which Gregg alluded (the "coma"), I have no problem with its very existence. In fact I find it fascinating. There have been many revisions in the taxonomy of Pythonidae but virtually everyone agrees that Aspidites deserves its own genus and that its members are different from members of all of the other genera. In creating this cross all that we know about Pythons and certainly the Linnean classification of Pythonidae has been thrown upside down. Should it be done again? I don't know. What should be done with these animals? Grow them up and see if they are fertile.

What is a bad reason to hybridize? Profit.

 

[Gregg M]

Well Jim, I can always rely on you for an intelligent post even if I do not agree with it.... You are one of the few people who make me rethink my views sometimes...LOL....

Thats what I am looking for..... Someone to argue against my point of view without the usual mindless phrases and the "We do it because we can" attitude....

Anyway, thanks for your input Jim..... It is always welcome on one of my threads....

 

[coyote]

I entered this issue from the point of view of an artist. Some of the hybrids are aesthetically exquisite.

Then, as my education on the hobby increased I began to look at the issue more like a scientist. I have become much more emotionally, if intellectually, invested in the issue of conservation. Conserving the natural genotypes. Granted I might be overreacting; but I find the careless and common hybridization of the available captive population alarming.

I am not militant in my position, nor am I naive enough to think that it could be totally halted. In fact there just might exist viable reasons for experimenting with hybridizing certain species. If anyone can provide such viable reasons I am eager to consider them.

Conversely, My opinion is that the conscientious work of those that breed to maintain the pure, natural genotypes will prove to be of greater value. And, dang it! I want to see DNA typing/testing become established practice and be commonly available.

 

[alexandertsebelis]

Gregg M, Not trying to start an argument, but as far as I understand a hog island boa is a Boa Constrictor Imperator, or a "common boa"/"central american boa", the same subsecies as Colombian boas (not the "True" red-tail colombian, Boa Constrictor Constrictor), Cancun boas, and sonoran desert boas, just to name a few. I completely understand your point, since hogs are probably extinct in the wild it is important to maintain real hog island boas, but it is also important to have healthy bloodlines.

 

[sirenofthestorm]

Alexander, those are subspecies, not species designations. Any 'mixing' of subspecies is termed an intergrade, and not a hybrid.

 

[alexandertsebelis]

Intergrades

I know that, this is what Gregg said:

Look at Boas for example..... Do you know for sure you are getting a pure hog or any other sub-species???

A hog island boa is the same subsecies as "central american boa" so it is not even an integrade, because they are the same subscies.

 

[alexandertsebelis]

Even if they arent pure hogs. hogXcancun boa= central american boa hogXcorn island= central american boa (central american boa is a kind of loose term for BCI "mutts")
Boa localities are not subspecies, and they are definetly not full species. They are kind of like breeds of dogs. Labrador retrieverXgolden retriever=mutt, central american boa=mutt, central american boa=/hybrid=/integrade.

 

[paulh]

Alexander, those are subspecies, not species designations. Any 'mixing' of subspecies is termed an intergrade, and not a hybrid.

Seems to me that "hybrid" is perfectly acceptable in the context. Definition of "hybrid":
1 : an offspring of two animals or plants of different races, breeds, varieties, species, or genera

Source: Merriam-Webster's Medical Dictionary, © 2002 Merriam-Webster, Inc. (see www.dictionary.com)

 

[Scott Thomson]

If you are going to define a hybrid I would suggest you use its biological meaning in this context not that of some dictionary.

Biologically a hybrid is a cross between to individuals that represent the lowest taxonomic ie species. Thats basically a summary from Mayr's Principals of Systematic Zoology.

So a hybrid is a species cross, which is what people have mostly aluded to here.

In my own research (I am a taxonomist and have worked with a lot of natural hybrids) I have found that the ability to hybridise is actually the norm and the inability a derived condition. Inability includes unsuccessful hybridization ie infertile offspring. A viable hybrid to be successful must be able to produce a second generation.

Interestingly one of the species I described, Chelodina canni McCord and Thomson 2002, has not only viable wild hybrids (demonstrated using electrophoresis) but the hybrids have hybrid vigor which is the hybrid is a larger, stronger animal then either parent species. Turtles of the genera Chelodina and Macrochelodina are also capable of multiple hybridization. For example a Macrochelodina rugosa x Macrochelodina parkeri offspring can successfully breed with a Chelodina novaeguineae, resulting in a 3 way hybrid.

My point in this is that as hybridization is a primitive condition it actually cannot be used in taxonomy. Hence the fact that two species can hybridize or even different genera has absolutely nothing to do with wether or not the parent populations are different species, or any other higher taxon.

You cannot call subspecies crosses hybrids because by definition a subspecies must be able to breed with other subspecies, and successfully. A subspecies is an allopatric population that in 75% of cases can be distinguished from 100% of the individuals of another subspecies of the same species (again from Mayr). That is all. Subspecies are geographic variants of the same species and do not represent a taxonomic unit, the smallest unit in taxonomy is the species, it is also the only real taxonomic unit. Subspecies are matters of convenience and interest only.

Ok now that I have put up what is and is not a hybrid and its importance taxonomically. From a breeding perspective they should not be bred. Here in Australia it is actually illegal in some states to produce them deliberately. When hybridising animals you are playing russion roulette with their lives there is no garuntee what will happen, the genetic mix may kill them, leave them with a life of pain and suffering or on rare chance give a reasonably healthy animal. No garuntees.

Cheers, Scott

Scott Thomson

 

[hhmoore]

Right. A cross at anything above the subspecific level is a hybrid. The term intergrade is used when subspecies are crossed. I actually get a kick out of people that vehemently speak out against intergrades, for the following reason: They occur in nature. Who is to say that the founding stock of any carpet python is "pure", when several of the subspecies are known to interbreed. The same goes for Rattlesnakes of the lutosus complex. There are numerous examples, but that point has been made. Personally, I like many of the intergrades - in some cases, they can be be stronger, heartier, and more beautiful than the pure forms. Conversely, I am not a proponent of hybrids...sure, some of them are interesting - but alot of that is just "freak fascination". Break out the proof that the animal is as strong, or stronger, than the originating species, and I'll be happy to reconsider (your examples are duly noted, Scott...and very interesting)

As for the

 

[Scott Thomson]

One thing I neglected to mention in the wild hybrid zone for C. canni x C. longicollis is that although they have an apparent hybrid vigor (female hybrids are up to 30cm (15 inches) carapace length easily 5 - 8 cm (2.5 - 4 inches) longer than either parent species) the hybrids are restricted to the overlap zone between the two species. This says that despite the larger size and aparent success of the hybrid locally it is incapable of competing with either parent species hence does not extend its range beyond a few kilometers north or south.

As for intergrades, this is actually also a specific term and is resticted to cases of interbreeding between subspecies where they overlap. Personally I think that the presence of intergrades shows that the two forms are not subspecies but are the same subspecies. They actually fail the defining test of a subspecies which is that they are allopatric ie never occur together. So if intergrades are found how can this be true.

So intergrades are only crosses between subspecies that are found geographically next to each other in the wild.

If someone is crossing subspecies from opposite sides of the country they are just crosses, nothing more, they are not intergrades as intergrades can only be wild caught and can only be between abutting populations.

Wether they should be crossing them is up to the individual, personally I would not allow anything to breed that is potentially different.

Hybrids of course are another matter and they should not be produced.The hybrids I work with a wild hybrids, freaks of nature if thats the term people want, but they have not been deliberately produced and are matters of scientific interest to me only.

Cheers, Scott

 

[hhmoore]

As for intergrades, this is actually also a specific term and is resticted to cases of interbreeding between subspecies where they overlap. Personally I think that the presence of intergrades shows that the two forms are not subspecies but are the same subspecies. They actually fail the defining test of a subspecies which is that they are allopatric ie never occur together. So if intergrades are found how can this be true.

So intergrades are only crosses between subspecies that are found geographically next to each other in the wild.

If someone is crossing subspecies from opposite sides of the country they are just crosses, nothing more, they are not intergrades as intergrades can only be wild caught and can only be between abutting populations.

I must have edited out the part about range overlap. I got a bit verbose, and my post wandered quite a bit...I chopped at least half of it before it was submitted. Once again, some good points - I hadn't considered the last one.

 

[Pythonbreeder99]

people often say in defense of hybribization "if it can happen it will happen" but that often isnt the case. for example the "liger" or lion tiger hybrid. theoretically a lion and tiger could physicly breed but locality would prevent it. or when refering to herps the "super ball" or blood x ball python hybrid could happen but would never happen in the wild. and most of these animals ate sterile anyways so i dont think we should do it period.

 

[longfeather99]

a blood ball, or a super ball is totally fertile. Roussi's reptiles have bred F1's, @'s and i think 3's. I agree that nothing about how we keep snakes is "natural". I really feel that if you wanna keep blood lines pure and such perhaps morphs should not be bred, and many of them, like albinos, cant and usually dont survive in the wild. I'm not sure how true this is for reptiles, but i know that some kinds of albinism or colorings in animals are linked to bad or lethal genes. Simply because there are unscrupulous people out there shouldint be reason enough not to breed hybrids. By that logic, since there are irresponsible/uninformed people out there, no one should have large snakes or varinids. A lot of the hybrids i have seen have quite a bit of hybrid vigor. I used to breed king snakes and would regularly cross them with corn, gopher and milk snakes. Were there deformed offspring? Sure, but no more than you would get in a non hybrid clutch, and just as most breeders do, i culled animals that were deformed or otherwise defective. The demand for designer animals seems to be growing in so far as i can see) and realistically, you can only get so many morphs out of say a ball python. In short, im not a big fan of trying to tell people what to and what not to do, i feel that we have enough people trying to tell us as reptile keepers what we can and cant have.