Question about mixed specie breeding

[mightymizz]

In another thread, someone mentioned that some baby pictures looked like a cross breed of Redfoot and Leopard tortoises.

Sorry if my questions are common knowledge, but I just don't know the answers.

1. Would it even be possible to get babies from this union?
2. If yes, would these babies when they get old enough be able to reproduce, or would these babies be sterile?

3. Would anything change in how you feed and/or raise these babies since they would be a mix of the two species?

I am in no way saying I support cross breeding, but I am just curious about how this works for tortoises.

Thanks guys.

 

[wellington]

They probably could cross Breed, but should never be in the same enclosure for this to ever happen in the first place! As for the rest, might depend on what they come out looking more like.

 

[dmmj]

Mixed breeding between red foots and leopards would be impossible, they were commenting on the color patterns if I remember correctly. Since a pairing like that could not happen, no offspring would be viable what so ever. Personally I am against hybrids (sorry JD) but If I had one I would not treat it any differently.

 

[EricIvins]

Mixed breeding between red foots and leopards would be impossible, they were commenting on the color patterns if I remember correctly. Since a pairing like that could not happen, no offspring would be viable what so ever. Personally I am against hybrids (sorry JD) but If I had one I would not treat it any differently.

You know this how?

 

[mightymizz]

So scientifically, leaving out our personal thoughts/perspective, it would NOT be possible for these two species to mate producing viable eggs that could then hatch? This is the answer I am looking for.

Then if they could produce babies, would those babies then be sterile or no?

I am really not trying to start another debatable topic regarding "should" this be done or not, I am really just asking for my knowledge of how these things work or don't. The prior thread I referenced just got me thinking about this and how it works or not in tortoises.

 

[Madkins007]

While imperfect, taxonomy is our method of sorting animals by physical characteristics in an attempt to determine both the evolutionary lines and genetic closeness of species. If two species can successfully interbreed and regularly produce fertile offspring, we figure they are closely related and place them at least in the same genera, and usually in the same species.

The underlying idea here is that successful crossbreeding is based on similar DNA. The more compatible the DNA is, the more likely the crossing will work. Since DNA also controls physical characteristics, the whole thing works most of the time.

Current theory places red-footed and leopard tortoises in different genera (Chelonoidis vs. Stigmachelys), which suggests that successful crossbreeds would be unlikely, and if they did occur, would likely be sterile.

More practically- the only interspecies red-footed cross I am aware of is a single example of a red-footed x radiated cross that is, as far as I can tell, is poorly documented and seems to be based primarily on a single small photo. If red-footeds (or, for that matter, most other species) interbred easily, there should be a lot more good examples considering how long they have been kept as pets and how many keepers mix species.

Properly documenting tortoise hybrids is tough- tortoises are documented to store sperm and it has been shown that at any given time, a female uses a mix of sperm from donors over several years to fertilize eggs. So, unless there has been a excellent, long-term program of separation, or a DNA test, claims of hybrids should be taken with a grain of salt.

 

[mightymizz]

Mark, thanks for the response. Really appreciate the more scientific explanation as this was what I was looking for, just for my own knowledge about torts!!

Thanks people!

 

[GeoTerraTestudo]

In another thread, someone mentioned that some baby pictures looked like a cross breed of Redfoot and Leopard tortoises.

Sorry if my questions are common knowledge, but I just don't know the answers.

1. Would it even be possible to get babies from this union?
2. If yes, would these babies when they get old enough be able to reproduce, or would these babies be sterile?

3. Would anything change in how you feed and/or raise these babies since they would be a mix of the two species?

I am in no way saying I support cross breeding, but I am just curious about how this works for tortoises.

Thanks guys.

Hey, I think you might have misunderstood my post. JD was showing pix of redfoot tortoises that had somewhat unusual marbled patterns on their shells (most redfoots have a black carapace, hence the species name, "carbonaria"). I said that this reminded me of leopard tortoises, which are famous for their dappled shells. However, I did not say this because I believed the tortoises to be hybrids; some lines of redfoot tortoise are known to have marbled shells.

In answer to your question, however, I doubt if a redfoot and a leopard tortoise could form a viable (surviving) hybrid, let alone fertile one. As Mark explained above, redfoots come from South America and are in the genus Chelonoidis, while leopard tortoises come from Africa and are in the genus Stigmochelys. Therefore, within the tortoise family, these two species are pretty distantly related.

The most distant tortoise hybrids I know of are JDs lepracuttas, which are half leopard tortoise and half sulcata. They are viable, but it's too soon to know whether they are fertile or not. The two parent species are in different genera, but are both from the Eastern Hemisphere. Leopard tortoises and redfoot tortoises are probably even more distantly related, since they are not only in different genera, but also from opposite hemispheres.

Mammals and birds have chromosomal sex determination. In mammals, it's the males that are heterogametic (XY as opposed to XX); in birds, it's the females (ZW as opposed to ZZ). In hybrids, it's the heterogametic sex that tends to be sterile, while the homogametic sex may or may not be (Haldane's Rule).

Reptiles have temperature-dependent sex determination, so Haldane's Rule might not apply. Maybe JDs hybrids will turn out to be fertile, maybe not. It depends on how many genes in leopard tortoises line up with the genes in sulcatas.

So again, leopards and redfoots are so distantly related, that it is doubtful they can form viable, let alone fertile offspring. But given reptile genetics, it's possible ... and still to be avoided!

 

[mightymizz]

Thanks! Another superb response.

Just FYI, I knew you weren't trying to say they were a cross, but just the thought in my mind led me to these questions. I am just used to dogs from all over the world being able to produce offspring (for example) that I had the same questions regarding tortoises.

Thanks again folks, I learned some new stuff!!

 

[GeoTerraTestudo]

Thanks! Another superb response.

Just FYI, I knew you weren't trying to say they were a cross, but just the thought in my mind led me to these questions. I am just used to dogs from all over the world being able to produce offspring (for example) that I had the same questions regarding tortoises.

Thanks again folks, I learned some new stuff!!

Dogs from all over the world belong to a single species: the wolf. That's why, other than great differences in size, they are all capable of interbreeding and forming fully viable and fertile offspring. Likewise, cattle from all over the world are domestic aurochs, and sheep from all over the world are domestic mouflon. There are some hybrids we can discuss (dogs/wolves may hybridize with coyotes or golden jackals under some circumstances, although this may lead to some problems), but generally speaking, breeds all belong to a single domesticated species, and have been separated from each other for no longer than hundreds to thousands of years.

In contrast, all the different varieties of tortoise out there belong to naturally occurring subspecies, species, and genera. In the case of subspecies (like eastern vs. western Hermann tortoises, for example), relatively little time may have passed; on the order of thousands to tens of thousands of years - longer than with artificially selected domestic breeds, but not necessarily very much longer. When you're talking about species, though, you're talking about hundreds of thousands to millions of years. And when you're talking about different genera, you're talking about millions to tens of millions of years. That's a lot of time for genetic differences to accumulate.

 

[Tom]

Post number 10 is great GTT.

I don't have a definitive answer for the original question either, BUT, given the number of members all over the world here, the number of combined years of experience, and the way tortoises are kept all over the world... If it were possible for these two species to breed and produce offspring I would think somebody, somewhere, would have at least heard of it, or know somebody who knows somebody, etc... Since none of us have never even heard of a cross between these two species, I am willing to bet that it is not possible.

 

[mightymizz]

Once again, thanks so much everyone! This forum has been great for learning and sharing.

Thanks again for your time and responses!!

 

[nickpanzee]

Correct me if I'm wrong, but I believe it was my post of an ad on fauna that sparked this. I said they looked like they had leopard tortoise markings which I thought was interesting because I've never seen any red foots marked like this. They are quite pretty. I didn't know that red foots could have such coloration.

http://www.faunaclassifieds.com/forums/showthread.php?t=324071

 

[Madkins007]

While those are really interestingly colored animals, using markings as the main determination of a cross is not usually helpful when you consider how variable most tortoises are.

 

[nickpanzee]

Yeah. I wasn't saying they were a cross. I just thought they looked cool because of their markings. I thought most red foots looked generally the same in shell pattern as babies, but these little ones kind of made me go, "OooooOOOoooo"

 

[starfield]

Here are one of the babies in question... I'm hoping they aren't a hybrid... And am very happy to see the above responses... Certainly very interesting addition to my group.... No if I could only get my hands on a sexy hypo or albino

 

[GeoTerraTestudo]

No picture shown. Please try and post again.

 

[starfield]

Hopefully this works this time

 

[GeoTerraTestudo]

Nope, still no picture.