Inter-species breeding

Someone over at kingsnake.com brought up an issue about interspecies breeding (actually they brought up the issue of intersubspecies breeding but I think they meant interspecies). Whatever - I thought the subject was rather thought provoking. What do you guys think of breeding snakes interspecies? Has anyone accomplished this? Were the offspring basically normal snakes, albeit crosses of the adults? Were the offspring able to reproduce or were they mules? (Although I recently heard it reported that a real mule has reproduced). And what about inter-genera breedings?

As for me I think it is ok, so long as it is not producing absolute freaks like snakes with deformities. I think that such would be a help to geneticists, and possibly advance scientific and medical research. I also think it may produce some really nice snakes dependent on the crosses possible. It certainly would make the hobby a bit more interesting. What do you think?

Best regards,
Glenn Bartley

Yes Glenn, both interspecies and intergenera crosseshave been done.
Unfortunatly the promoters of these mutts have even added catchy names to the snakes.

Borneo Bat Eaters are Burmese X Retic
Jungle corns are Cal Kings X Cornsnakes
Carpondros are Carpet pythons X Green Trees
One phase of cornsnake, I believe Creamsicle is Corn X Emoryi
Jurassic Milks is another, but I can't remember the species involved.
Bubblegum rats is a 3 way hybrid if I remember correctly.
And the old faithful Diamond X Carpet cross that originated years ago in part because of the low survivability of pure diamonds in captivity.

Further, albino nelsoni and ruthveni have both been crossed into other species including alterna and sinaloans in order to artificially introduce the albino gene into these snakes.
The off spring are normal snakes, well as normal as a taxonomically unclassifiable snake could be. They are also fertile.

I personally am against hybridization. I can see nothing it can contribute that will benefit the hobby, beyond creating more oddities and eye candy for the marketplace.
It does however pollute the gene pool, and over the next 20 years or so that influence may be felt much more than we may expect.
While there are many who vehemently argue the point, since they themselves are honest people, there are hybrids that reach the market as pure animals.
For instance there is an ad in the k.com classifieds right now for Jurassic Milks, and it mentions nothing about them being hybrids, let alone listing the species the cross was from. While this is not an attempt to pass them off as pure, neophyte keepers may not realize the history of those snakes. I've had numerous people ask me what the taxonomic name of the Borneo Bat Eaters is, trying to learn more about them. Of course there is no name for them nor ever will be, these people just didn't realize that they were hybrids.
This is especially a possibility concerning genetic mutations. There are those that rather than wait for an albino of a given species to be discovered, they may instead introduce the albino gene from another species. Then, through selective breeding to the desired parent species, the influence of the albino contributor can be bred out.
I speculate that this has already happened a time or two, however I could be wrong.
It is done in the dog world. White schnauzers are an example. In the original refining of the breed, white was an undesired color and was bred out. Therefore true white schnauzers are quite rare today, although they do exist. I have one myself. Given the rarity however, the value of these dogs is much higher than normal colors, and that provides the incentive to artificially create them. A Westie is normally used to introduce the white color, then through a few generations and many destroyed pups, the schnauzer appearance is bred back into them and they are registered using papers from another pure blooded breeding, and they have mutts that will sell for 2-3 times the price of pure blooded dogs.

It's easy to see how this same situation can arise in herpetoculture. The potential for monetary gain can be quite high in some species, and that's all the incentive that's needed.

I've heard all manner of justification for working toproduce hybrids, including "scientific reasons", and just to see if it could be done. None hold water with me though.
There might actually be an unseen benefit from hybrids to the genetic or medical community, I won't rule it out. However such animals produced for lab research will not be entering the marketplace of the private sector most likely.

I've ranted enough I suppose. I am against hybrids as an unnecessary pollution of the gene pool that carries the potential of being introduced to a breeding colony unknowingly.
I will not own hybrids, and normally don't do buisness with those who produce them.
While nothing will ever stop the practice, there are purists like myself that will never condone it.

You make some good points, but I am a bit confused when you compare different dog breeds to inter-species breeding of snakes. I can see the similarities but there are some marked differences. When someone introduces one breed of dog to another to reintroduce a color or other trait into the breed - this is not inter-species breeding. All domestic dogs are the same species, and sub species - if I understand correctly: Canis lupus familiaris. I always thought that breeds were considered as sub-species but I stand corrected by what I have found on several websites. So when someone introduces a white terrier (or whatever) to a gray Schnauzer with the intent of later producing white Schnauzers by selective breeding, they are not accomplishing an inter-species breeding project, but they are hybridizing. Otherwise, even in your example about Schnauzers, I see what you mean. As for your being a purist and never owning a hybrid, you own one already in that Schnauzer of yours. Whether or not it is pure Schnauzer, its original Schnauzer ancestors were the result of crossing different breeds of dogs to arrive at the breed known as Schanauzer. As far as I am aware, this is true for all domestic dogs as we know them.

I still have no problems with interspecies breeding so long as people who do it are honest when they sell the offspring. I do have a problem with dishonesty and fraud, and that would be what happens when someone trys to sell me an albino X snake when it actually is an albino cross of a normal X snake and a Y snake (or is one of their offspring, or their lineage). I see nothinmg wrong with making a buck off such breedings, as long as it is honestly done. I do see lots of possible scientific and medical benefit coming from actual inter-species or inter-genera breedings especially as it relates to genetics.

Best regards,
Glenn B

My intent was not to compare dog breeding to reptile breeding. I normally refrain from mentioning other organisms in a discussion about herpetological hybridizing, but the example of the white schnauzer came to mind only on the basis of people wanting a pure animal as opposed to a cross.
You are correct in that the crossing of dog breeds is not an accurate comparison to that of reptiles. All domestic dogs are of the same subspecies, and crossing them is not even hybridization, since they are all the same animal as far as scientific description goes. If my dog is a hybrid, then it would be because during the initial domestication 10,000 or whatever years ago, that two different types of wolf were used, not because several breeds were contributed in the creation of the schnauzer.
Technically speaking, a breed of dog would be the equivalent of a color phase of cornsnake as compared to cornsnakes as a species. Crossing two breeds of dogs is no more hybridization than crossing two different phases of cornsnakes. When comparing, on a scientific level, an amelanistic cornsnake to a banana cal king, the respective morphs are irrelevant, you compare E.g. guttata to L.g californiae. The same is true with dogs to wolves, since all dogs are taxonomically equal. How though would you compare a Jungle corn to a sinaloan milk?
Dog fanciers look upon their chosen breeds the way we look at snake species for all intents and purposes. While they do not consider the scientific aspect as we do, they do view each registered breed as being seperate from the others regardless of the scientific inaccuracy of that opinion. For this reason they are equally as disturbed about the possibility of buying a cross breed dog thinking they are getting a registered pure breed as we are in buying a snake that is only 75% pure thinking we are getting something else. That was my reasoning in mentioning the white schnauzer.

In addition, dogs being a single taxonomic group allows this crossing to create breeds exactly like the crossing of cornsnake morphs allows the creation of new cultivars without risking the taxonomic integrity of the species.
In herpetoculture as a whole however, we do not have this tidy system. We have many species involved, making it impossible to create only breeds as has been done in dogs. Once two seperate species or even genera of snakes are mixed they have forever lost their identity. They can never be classified as anything other than the market savvy name given them by the breeders. You can't say with accuracy what they are beyond "snake".

The key difference between hybridizing herps and the crossing of any domestic species is usefulness. Dog breeds were derived from a common ancestor purely in captivity to serve purposes according to the breed. Some dogs were bred for protection, some for farm work, some for hunting, and others for pest control (rat terriers etc.) We also have the benefit of established registration systems in place for this and other species to keep track of things.
Likewise, the crossing of cattle and other livestock, as well as plants like apples also serve to aid humanity in their existance.
All of these examples are often given by promoters of hybridizing herps as justification for the practice in reptiles.
In herpetoculture however, there lies no such usefulness. Monetary gain and curiosity are the only two real reasons the practice is done at all. Neither are strong enough reasons in my mind to justify the risk of polluting an unknown segment of the gene pool.

I have been confronted with the reasoning that since I own a dog, eat farm raised meat, and hybrid plants that it is hipocritical of me to be against the hybridizing of reptiles. What we do domestically though has no bearing on reptiles. This is aside from the fact that in the majority of instances such crosses are done within the confines of a species, or at least genera.
The fact is that all other areas are of little to no concern to me. My interest lies in reptiles alone and with that I afford myself the luxury of having two opinions. For this reason my statement about never owning a hybrid was in reference to reptiles alone, as I have no concern with other animals. Let those whose interest lies there worry about how they approach it.

I still have no problems with interspecies breeding so long as people who do it are honest when they sell the offspring.

In an ideal situation, I would immediately agree with you. However this one statement is both reason to approve of it for some and reason to disapprove of it for others.
The fact is there are some who are dishonest, and others who are honest, but simply don't realize that one of their breeders is only half what he thinks it is.
Either way, the result is hybrids entering the genetic pool as pure specimens.
It has happened before, and will continue to happen at times, the question is not whether damage will be done, but how much.

I acknowledge the possibility of some unseen use for hybrids to medicine or genetics, but I can't say there are lots. In either application, I just can't see a situation where a hybrid would be of use in an area where a normal, genetically pure animal would not.
Perhaps medically, certain crossing of venomous species may result in something of benefit, but the possibility, or even the general direction of the experiment would be very difficult to discern beforehand. Instead it would likely be an accidental discovery.

"Once two seperate species or even genera of snakes are mixed they have forever lost their identity. They can never be classified as anything other than the market savvy name given them by the breeders. You can't say with accuracy what they are beyond "snake"."

This is excactly where I think you would be very wrong; that is if the offspring of such a mating were to later breed true and reproduce themselves or reproduce faithfully something that was not the equal of either original interspecies parent. If an interspecies mating of snake A and snake B produced snake C, and then matings of snake C to another Snake C produced only Snake C (or even only snakeD); and then if those offspring bred true reproducing themselves faithfully, then it would be quite possible that a new species would have been created. If the genetics of the Snake C or Snake D were different than both Snake A and snake B such would be the case. This would have huge scientific, and medical implications with regard to gennetic applications. Because of such implications the next part of you argument that:

"In herpetoculture however, there lies no such usefulness. Monetary gain and curiosity are the only two real reasons the practice is done at all. Neither are strong enough reasons in my mind to justify the risk of polluting an unknown segment of the gene pool."

No matter what we think of the subject, such breeding attempts are being made by hobbyists. If succesful breedings take place interspecies, that lead to the creation of viable offspring that then develop a new strain that breeds true - and if these differ genetically from their ancestors - this would be big science. Big science will inevitably, sooner or later, attract scientists, and somewhere along the line, there would likelky be a benefit from this. If nothing else, a hobbyist may also be doing this for the knowledge about breeding he/she could gain on a personal level. As far as breeding them for money goes, as I said, if the breeders are honest great. If not, that is fraud and they should have their kneecaps..... (well let me hold that thought). Sure the dishonest ones can corrupt the gene pool; there is always a chance of getting a mutt (there we go with dogs again), that is a chance you take when you buy any animal.

Bear in mind that a lot of scientific and medical research has been bolstered by things that were not at first intended to do just that and that were not scientific ventures in the first place.

I am pretty sure we will not wind up agreeing on much here, I think we are sort of on opposite sides of the coin on this one (even though I do not yet have my animal experimentation mad scientist lab set up just quite yet - LOL), but I do respect your opinions. You make a very good argument.

Best regards,
Glenn

If an interspecies mating of snake A and snake B produced snake C, and then matings of snake C to another Snake C produced only Snake C (or even only snakeD); and then if those offspring bred true reproducing themselves faithfully, then it would be quite possible that a new species would have been created. If the genetics of the Snake C or Snake D were different than both Snake A and snake B such would be the case. This would have huge scientific, and medical implications with regard to gennetic applications.

Just for clarification, are you stating that a completely new species could be artifically created in captivity? One that would be recognized by science and receive taxonomic classification? If it isn't recognized, then it can't be considered a species.

If so then every person breeding snakes holds the potential of having a new species described and named after himself.
If this statement is true, then would it also be true for the crossing of genera? Where would these hybrids be classified? Would a new genus be created?

Extrapolate this to other classes of organisms commonly kept in captivity. The effects of such a scenario on taxonomy would be serious, and I simply can't see the actual creation of a new species ever being accepted.
I still maintain that once species or genera are crossed that their precise taxonomic identity is forever lost, they are at that point unclassifiable.

I'm not sure what you mean by genetically different. More precisely what degree of differentiation you feel would be required to result in something of scientific interest.
Much of the serious genetic science is abstract and do a degree intangible to me. Perhaps this contributes to my lack of being able to envision possible implications of hybrids in this area.

It can be safely assumed that we will not come to an agreement in this discussion. I participated in a debate on the topic spanning several months in 1999, and while it proved a very interesting discussion no ground was gained or given and I have rarely broached the subject since. This topic is more or less our hobby's abortion issue. None the less, it is interesting to discuss.

If an interspecies mating of snake A and snake B produced snake C, and then matings of snake C to another Snake C produced only Snake C (or even only snakeD); and then if those offspring bred true reproducing themselves faithfully, then it would be quite possible that a new species would have been created.

This is going to be a bit harsh Glenn but that is just plain outright wrong.

Based on the definition of a species, the interbreeding population HAS to be present in the wild and organisms crossed under lab conditions don't qualify as anything other than artificially produced aberrancies.

There is more to the issue of hybridization than merely genetics or if an animal "Can" be crossed in captivity, there are natural behavioral traits that work to isolate species from one another as separate breeding populations beyond simple genetic possibilities.

There are a number of naturally occurring hybrids but this can be put down as poor initial knowledge of the species natural history and they could, after sufficient study to verify the interbreeding, be categorized as subspecific designations of the same species.

For a more complete understanding of my arguments on the matter, please read the following thread where Rob and I went back and forth over this same issue, since the topics seem to have become essentially identical towards the end, perhaps we could merge them into a single discussion with all the participants involved.

http://www.faunaclassifieds.com/foru...threadid=12107

Ironically, I agree with Seamus on the issue of a new species being created in captive conditions. Although, as we've discussed, there are natural hybrids that eventually became recognised species, these occurred under wild NATURAL conditions. A population of kings and milks that have a natural intergrade zone could possibly give rise to new subspecies and/or species under natural conditions(ex: red milks and blotched kings).

I will side that captive hybrids are fascinating and that I think there's no problem with people breeding them, but new species they are not.

I have spoken to two scientists a biologista and a herpetologist about this, and to a developmental psychologist who deals heavily in genetic theopries. and all agree that if the new hybrids bred true and had a chromosione count that was different thatn either of the two snakes that crossed in the first place, then it would indeed be a new species. The breeding true part is the hard part as most crosses wind up being mules or sterile. I only point this out as a possibility. Once upon a time not too long ago in the world of science there were lots of other things believed impossible that we now take for granted. Since snakes are able to reproduce across species lines and even on some occasions across gnerea lines, just imagine what would happen if they ever produced such offspring. Even without doing such, for an animal to be able to produce offspring from an intergenera breeding is something that deserves lots of scientific investigation. Is it possible that snakes are doing something no other animal is known to do, or is it more likely that we humans have screwed up their classification and many snakes (not all but some)are "breeds" like dogs instead of different species.

I do agree and acknowledge that a lot of our taxonomic classifications are probably pretty incorrect, or would turn out to be if a better natural history of the organisms involved were understood, but that is why they can change.

Intraspecies fertility is not an indication of two organisms being an identical species unto itself and neither is any similarity in their respective genomes, the most important factor in determining species is the question of naturally occurring reproduction, not simply the possibility of reproduction... There's a serious difference between the two concepts.

Since I don't want to clutter it up again, please view the other thread, specifically the quote by E.O.Wilson that I utilized on the second page over there for a better understanding of this.

Genetic compatibility under lab conditions is not entirely without use, it would help pinpoint animals that had common ancestry with much better accuracy than the all too often incomplete fossil chains that have been used in the past but common ancestry should not be mistaken as an automatic inclusion into the same species, merely the same genus or family grouping where no link was thought to exist before.

Hopefully I can do this without turning it into a debate about the validity of Darwinistic evolutionary principles because those never end and don't usually end up being much fun but...

A species is a group of naturally interbreeding organisms, in addition to simple genetic compatibility, there are additional factors of a behavioral nature that serve to isolate populations from other populations, however similar, even when occupying the same range and encountering one another...

A subspecies designation is given when there is a naturally interbreeding population of animals that are displaying a different phenotype which only interbreed across a narrow zone of intergradiation or those which have a larger range and the animals at assorted ends can be said to be isolated from certain other animals in the population, the size of the range causes the animals to evolve to meet different conditions and thus the subspecific designations are given.

A genus, very very very very loosely defined would be a group of species that can be hypothesized to have common ancestry relatively recently in terms of biological history, they share broader common traits and would be similar on a genetic level...

Now comes the fun part where I try and simplify evolutionary theory into a few sentences...

Given a basic premise that animals evolve over time, altering subtly as populations meet assorted factors (I'm not willing to argue about creationism, I respect the views of those who believe in it but currently accepted taxonomic science is based in evolutionary principles), this can change all of a population or it can change parts of a population depending on the factors the organisms are altering to meet. Looking at species with a larger range, it's easy to accept that the individual animals at extreme ends of a population will encounter different environmental conditions, different predators, different prey, different geographical features and so on... the animals in a given area will alter on a biological level to adapt to the local conditions. Given multiple successive generations adapting to different conditions, the populations might look very different... more importantly they will likely act very different, respond to identical stimulus in subtly different ways and, most importantly, have developed different imperatives and instincts for breeding. The period of time when the population still represents a breeding group but displays separate characteristics is a period of time when they can be classified as a subspecies, the period of time after they cease interbreeding would be when a separate species classification is warranted. As Rob pointed out, the process can work in reverse if the populations are forced back together early enough in that development, when such is found to be the case, the taxonomy should be changed to place the animals in the same species with subspecific classifications designated to the -almost- isolated populations.

The important factor in all this is that it happens naturally, at a seemingly monolithically slow pace, in response to naturally occurring events. Forcing the animals together in artificial conditions has a tendency to retard certain natural behaviors, which invalidates those intrinsic isolating mechanisms that keep the species separate in nature.

An easy example of species that theoretically have a common ancestor not too far back and certainly come into contact with one another would be say... Green tree frogs and grey tree frogs here in the U.S. The populations overlap, the animals are biologically very similar despite some outward differences in appearance, the mating seasons are similar and they are in the same Genus... So why aren't they interbreeding and why aren't they identified as the same species? Working off conjecture for a moment, I am fairly certain that they would be genetically compatible should someone take the time to artificially inseminate a few clutches of eggs, there could likely be a forced production of offspring... if you manipulated them enough, you could probably even get them to cross on their own in captivity... But they are not the same species and at this point appear far too separated to ever combine naturally (as in the examples Rob gave with the kings)... because of instinctive behavioral tendencies that isolate the populations from one another when it comes to copulation.

My personal opinion on Hybridization is quite negative, I dislike the idea of it occurring in the pet trade and I really don't see much point in forcing it under lab conditions since there are more accurate ways of determining the genetic distance individual species hold from one another. Subspecific intergradiation is a bit of a grey area for me, I make the determinations and form my opinion on a case by case basis, if there is a zone of significant interbreeding in the wild between the two specific subspecies in question, I do not mind them in captivity provided they are properly represented (although do still like the concept of a pure animal better), when dealing with species that have three or more subspecies, it depends on the natural likelihood of the subspecies in question crossing in nature, some are separate, some are not...