# Honest question about morphs



## rainforestbox (Jan 13, 2021)

Forgive me because this question might seem stupid but I understand that morphs are supposed to be kept separate. However, many morphs only start from a small shipment so there will inevitably be little genetic diversity. Coming from the reptile hobby, some animals like indigo snakes already are experiencing severe health problems from the lack of diversity. Is there that issue with frogs? If thats the case, would it really be better to have several captive populations of unhealthy frogs with clear locality verses one population of healthy frogs with unclear locality. I know that some species like terribilis are endangered in the wild and it would be a shame if the captive population after a few generations becomes unhealthy due to inbreeding


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## DPfarr (Nov 24, 2017)

These frogs are way past several generations of inbreeding. I haven’t read much about the deleterious effects on any of the species and the phenotypes. Maybe I might have read something about a limited genotype for highland sirensis/lamasii.


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## Chris S (Apr 12, 2016)

I can't comment on reptile genetic diversity, but I believe most captive dart frogs have proven to be quite resilient to many of the negative effects of inbreeding. I believe it is generally understood that outbreeding with many of these species is actually more detrimental than inbreeding. I don't have any sources, I believe I picked up this tidbit from reading many old threads on this forum. Maybe someone else will chime in with a bit more scientific background.


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## rainforestbox (Jan 13, 2021)

Chris S said:


> I can't comment on reptile genetic diversity, but I believe most captive dart frogs have proven to be quite resilient to many of the negative effects of inbreeding. I believe it is generally understood that outbreeding with many of these species is actually more detrimental than inbreeding. I don't have any sources, I believe I picked up this tidbit from reading many old threads on this forum. Maybe someone else will chime in with a bit more scientific background.


Thats really interesting, I think genetic disease may vary per locale so that may be why. I'm not sure how small the original import populations are as well.


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## Kmc (Jul 26, 2019)

What do we know most specifically, right now?


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## Anda (Jan 18, 2020)

Inbreeding does not cause evolution without natural selection and since there is no real selection in the terraria and no large populations, there is no evolution going on with the captive dart frogs. In nature these frogs will do pretty much anything to avoid inbreeding, which in itself speaks for the importance of avoiding it. In this article from 2006, they show that while inbreeding in pond frogs does not affect survival in captivity, they are outcompeted when returned to the wild. Here is a news article from Australia describing the problems with in tree frog inbreeding after the bushfires.
In nature there is also selection against inbreeding even when the populations are already severely inbred. Meaning that heterozygosity can increase by excluding the most inbred genotypes. 

While it is true that outbreeding can be a problem, it only applies in natural populations that are especially adapted to their specific environments. Again, not an issue in a terrarium.

Even though frogs are a lot more resilient to inbreeding than humans for example, inevitably it will become a problem. Every effort you make towards avoiding it will help the frogs long term. Trying to compose breeding groups that are not siblings for example. And to answer the OP, since there is no uniform natural adaptation in the terraria that support survival, mixing in morphs should decrease mortality or morbidity caused by inbreeding.


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## Johanovich (Jan 23, 2017)

rainforestbox said:


> Forgive me because this question might seem stupid but I understand that morphs are supposed to be kept separate. However, many morphs only start from a small shipment so there will inevitably be little genetic diversity. Coming from the reptile hobby, some animals like indigo snakes already are experiencing severe health problems from the lack of diversity. Is there that issue with frogs? If thats the case, would it really be better to have several captive populations of unhealthy frogs with clear locality verses one population of healthy frogs with unclear locality. I know that some species like terribilis are endangered in the wild and it would be a shame if the captive population after a few generations becomes unhealthy due to inbreeding


So for some frogs this mixing has already happened a lot in the past. The auratus costa rica that are commonly sold are a mix of the east and west populations in Costa Rica (unless specified). Same with most Epipedobates anthonyi that are sold. They are a mix of several localities unless specified (such as "rio saladillo" for example).

On the other hand several so called morphs are likely not true separate morphs. For example in auratus there are several bronze type morphs, which originally came from the same shipment but were separated by visual comparison or given new "invented" names over the years as they moved from country to country. The auratus highland bronze are a prime example of this. Originally this morph was collected by Birkahn and Wassmann in 1992. You can find some info on Dendrobates.org and an article was published in leaf litter some years ago about auratus morphs from Panama. In Phyllobates terribilis it is also unclear whether there are actual color morphs in the wild. I seem to recall that different color hues live together in populations, which would mean that our separation of yellow, orange and mint frogs is artificial (but I can't immediately find the source of this info again).

For the record I do not want to encourage people mixing morphs. However I do find this "inventing" of new names and the way names are given to animals very frustrating and stupid, as it just makes everything unnessecarily complicated and reduces genetic diversity. If it was clear where the animals were collected, we would at least know which ones could be safely combined to increase genetic diversity and reduce inbreeding.


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## Socratic Monologue (Apr 7, 2018)

rainforestbox said:


> Forgive me because this question might seem stupid but I understand that morphs are supposed to be kept separate. However, many morphs only start from a small shipment so there will inevitably be little genetic diversity. Coming from the reptile hobby, some animals like indigo snakes already are experiencing severe health problems from the lack of diversity. Is there that issue with frogs? If thats the case, would it really be better to have several captive populations of unhealthy frogs with clear locality verses one population of healthy frogs with unclear locality. I know that some species like terribilis are endangered in the wild and it would be a shame if the captive population after a few generations becomes unhealthy due to inbreeding


It isn't a stupid question, but it is a bit confused. Strictly speaking, the idea of morphs in animals generally is an artificial category, and isn't a categorization that is universally supposed to indicate natural divisions. 'Locale' sometimes does indicate natural divisions, but not always, and sometimes morphs are locale-specific, but not always. Some morphs are artificially created through line breeding (e.g. chocolate leucomelas), and so don't map onto anything but visual appeal to humans. Keeping 'locale' and 'morph' separate in discussing this is necessary to avoid false conclusions.

Neither morphs nor locales are subspecies (which seem to be getting dropped by taxonomists lately). Relatedly, subspecific and even specific differences are not always visually apparent, and visual identification of species is being pushed aside by taxonomists in the last decade or so.

In those groups where inbreeding is thought to be causing issues (as mentioned above, Highland sirensis) part of remedying those issues involves interbreeding lines of that locale. Many locales/morphs haven't been kept pure to line (that is, animals of a certain morph/locale haven't come from only one import event), so this deliberate outcrossing isn't an option.

I agree that the issue of outcrossing seems to be much more apparent in taxa such as snakes, at least many species of which manifest problems after inbreeding of only a couple generations (distinctly not all species, though; the line of L. micropholis I work with is said to be descended from seven WC locallity animals, and is apparently genetically unproblematic). 

Other species I'm not so sure about; _E. maculatus, _at least in hobby breeding, seems to suffer most distinctly from crossing lines of hobby-preserved mutations (e.g. genetic snows tend to be pretty weak, and stacking albino on top of that typically makes it worse). Outcrossing them to other subspecies seems to strengthen lines, but this of course wouldn't be done for species preservation purposes, so things are much more complicated than we've made them out to be here.


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## Encyclia (Aug 23, 2013)

It is in discussions like these that Ed would always bring up outbreeding depression. This was news to me when I first read it. Apparently it isn't a slam dunk that mixing morphs would be beneficial, genetically speaking.

Mark


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## Kmc (Jul 26, 2019)

We love Slam Dunks. They comfort us and we believe in them too much.


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## Vargoje3 (Oct 5, 2020)

I've heard that dart frogs don't show any negative affects of inbreeding until the 200th or so generation. I don't know if that is true or not, maybe someone knows more.


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## Chris S (Apr 12, 2016)

Encyclia said:


> It is in discussions like these that Ed would always bring up outbreeding depression. This was news to me when I first read it. Apparently it isn't a slam dunk that mixing morphs would be beneficial, genetically speaking.
> 
> Mark


I think this is one of the threads I was referring to...thanks for being less lazy than me and finding it!


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## Anda (Jan 18, 2020)

As Encyclia stated, genetics is everything but a slam dunk and variables are indefinite, so the only thing I can tell you for sure is that the number is NOT 200 and it that it would be different for each frog. In any case 200 is a mathematical estimate, if anyone ever did one and not an actual number.


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## Kmc (Jul 26, 2019)

There is no way of saying that with any accountable assurance. 

The 200 generation thing.


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## Robru (Jan 1, 2021)

The dorsal coloration on adult specimens of _Phyllobates terribilis_ is bright golden yellow or golden orange, or pale metallic green, depending on the location of collection. Occasional individuals were deep orange or pale greenish yellow. Ventrally the color is the same as or slightly lighter than the dorsal color, except for the underside of the hands and feet, which are black, and the undersides of the thighs, which have a black seat patch. There is also a black crease at the axilla and groin. The eyes, nares and digit tips are black. There is usually black edging on the lower rim of the tympanum. In many individuals the mouth is edged with black, and the creases of limb articulations are often black. Males generally have some gray coloration on the base of the throat. In some individuals there is also a light gray suffusing the axilla and groin, as well as the posterior of the venter and the concealed part of the shank. In individuals that are pale metallic green in overall color, the venter may be slightly bluish green and the concealed part of the shank is sometimes a definite blue-green. Variation in ground color hue was associated with microgeographic variation (i.e. frogs collected from a given ridge or slope area tended to be the same hue) (Myers et al. 1978).


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## tardis101 (Apr 11, 2012)

Unfortunately you are correct. Having been an endangered species biologist for nearly 20 years the frogs we have in the hobby are (mostly but not all) from very limited imports. Deleterious effects from even one inbreeding event can have substantial impacts on a population. Sometimes those impacts are not seen for a while but they are happening. Captive populations defiantly continue to evolve. We are selecting each generation (purposefully or not) for frogs that are better suited to life in a glass box. The froglets that morph out in little plastic cups may not be the ones that would have survived to morphing in the wild. Often folks will point to a single study on wood frogs that discusses the impacts of outbreeding and inbreeding and conclude that because the larger population suffered more deleterious impacts when mixed with the small population that outbreeding derepression is the greater issues. However, they tend to forget that the authors noted the small population already had a number of unhealthy traits. So that population had already suffered from a genetic bottleneck. If the smaller population would have been healthy it’s unlikely you’d have seen the same impacts to the larger population. Anytime you limit the genetic diversity in a population of vertebrates you will see an increase in deleterious alleles.l which will impact the health of the population. It still doesn’t mean you should cross a citronella with an Azureus. But it does mean one should try to get as unrelated individuals as possible (which may or may not be likely).


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## Chris S (Apr 12, 2016)

tardis101 said:


> Unfortunately you are correct. Having been an endangered species biologist for nearly 20 years the frogs we have in the hobby are (mostly but not all) from very limited imports. Deleterious effects from even one inbreeding event can have substantial impacts on a population. Sometimes those impacts are not seen for a while but they are happening. Captive populations defiantly continue to evolve. We are selecting each generation (purposefully or not) for frogs that are better suited to life in a glass box. The froglets that morph out in little plastic cups may not be the ones that would have survived to morphing in the wild. Often folks will point to a single study on wood frogs that discusses the impacts of outbreeding and inbreeding and conclude that because the larger population suffered more deleterious impacts when mixed with the small population that outbreeding derepression is the greater issues. However, they tend to forget that the authors noted the small population already had a number of unhealthy traits. So that population had already suffered from a genetic bottleneck. If the smaller population would have been healthy it’s unlikely you’d have seen the same impacts to the larger population. Anytime you limit the genetic diversity in a population of vertebrates you will see an increase in deleterious alleles.l which will impact the health of the population. It still doesn’t mean you should cross a citronella with an Azureus. But it does mean one should try to get as unrelated individuals as possible (which may or may not be likely).


A lot of this has a ring a truth to it, and I agree with, but in the absence of any true studies on captive frogs and inbreeding/outbreeding (that I have read), the Wood Frog example is one of the best we have to pull from in regards to outbreeding.

It should also be noted that many of these frogs have very long lifespans, so the originally breeding stock is likely still healthy and producing in many circumstances. For those looking to breed intensively, I think ensuring proper breeding stock is available is important. Speaking from the world of Ranitomeya, I know much of the original breeding stock from UE is still healthy and active, and has some genetic diversity to it. Many of the other large breeders have used this stock as a baseline as well, so I would suggest most frogs available on the market are still in the F3-4 range, with the F3/4/5 levels being the first to really experience much, if any, inbreeding. I may be a generation or so off here, if the farm operations in Peru didn't account for genetic diversity when breeding, but generally speaking most of the captive Ranitomeya population probably has very little deleterious effects on it right now. Maybe others, such as @Socratic Monologue can chime in on this as well. I can't comment on tincs or leucs...I think that is an entirely different realm.

On another topic, there is something important that @tardis101 touches on, in that we often coddle our tadpoles and froglets, whereas in the wild these would be aggressively culled by natural events such as starvation, predation, and weather. I would say very few breeders and hobbyists are up to doing this, but I will admit (for better or for worse) that I do occasionally humanely cull some tadpoles in an effort to ensure the genes moving on are stronger. This can include scenarios such as any noticeable deformity, slow development, tadpoles that developed accidently from young frogs in grow out bins and of course, there are some that just don't make it on their own (which in my eyes, is "ok", and I don't give preferential treatment for one over another). Further, any froglets that show issues such as deformities are often humanely culled as well. If I was keeping these young ones for a display tank, I might not bother, but I often sell off the youngin's, so their health and lineage are important for me as a sign of quality both to the purchaser, and to the hobby as a whole. Culling is still quite rare for me, and probably not even anywhere close to what happens in a natural environment.

Just some thoughts!


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## Robru (Jan 1, 2021)

Through selective breeding, Ivan Lozano* has developed a color “morph” of the golden poison frog known as the Phyllobates terribilis orange blackfoot, shown here. Exclusive color morphs created through captive breeding programs can help steer hobbyists away from wild-caught frogs.


















Photos by: Gena Steffens

* Ivan Lozano started _Tesoros de Colombia_ as a conservation program aimed at protecting critically endangered frog species such as Lehmann’s poison frog from extinction through captive breeding and sustainable biocommerce. The breeding center is capable of producing up to 1,500 frogs a year.


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## Anda (Jan 18, 2020)

It is always nice to hear from an expert!

Sorry, the rest of the post was written before reading Robru's post above. I had the same reference in addition to this article on biocommerce.


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## Socratic Monologue (Apr 7, 2018)

A couple points:

When we are cutting and pasting from sources, those sources should be cited, at least so that we can look to the original to confirm claims, consider context, etc.. The terribilis article in which Ivan Lozano is pictured is from National Geographic, here.

Second, that article has been heavily, heavily criticized here on DB, and this claim in specific



Robru said:


> Through selective breeding, Ivan Lozano* has developed a color “morph” of the golden poison frog known as the Phyllobates terribilis orange blackfoot, shown here.


has been debunked, as the blackfoot trait is naturally occurring, according to Tesoros. No selective breeding has taken place to develop that morph.









NatGeo Piece on Conservation and Smuggling, includes...


Article




www.dendroboard.com


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## Anda (Jan 18, 2020)

The question remains, could biocommerce be a legal and sustainable solution to the inevitable demise of the captive dart frog gene pool?


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## Socratic Monologue (Apr 7, 2018)

@Chris S :

Most of my knowledge of inbreeding comes from reptiles, where inbreeding is done a lot, sometimes involving many consecutive generations of backcrossing and sibling pairing. Sometimes (rarely) that leads to obvious deleterious effects (i.e. clear and debilitating malformations), but those are different from the effects that would be relevant in the preservation/conservation of endangered species -- which none of us here is doing. 

In fact, nearly all of the morphologically distinct characteristics that hobbyists try to increase, refine and propagate *are* deleterious, from the point of view of a wild species. Natural selection and artificial selection tend to have wildly differing, often opposing, values. Even keepers who think they are exercising some sort of natural selection (I read of a frog breeder who doesn't help new metamorphs out of the deli cup, since only the fittest should survive), but selective pressures in captivity are quite different from those in nature (the ability to climb PET plastic does not help a wild frog one bit, and is quite possibly maladaptive since some foot structures that favor climbing plastic could well be maladaptive for climbing tree bark).


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## Robru (Jan 1, 2021)

Socratic Monologue said:


> When we are cutting and pasting from sources, those sources should be cited, at least so that we can look to the original to confirm claims, consider context, etc..


Clearly. I will add the source reference in the future.


Socratic Monologue said:


> Second, that article has been heavily, heavily criticized here on DB, and this claim in specific
> has been debunked, as the blackfoot trait is naturally occurring, according to Tesoros. No selective breeding has taken place to develop that morph.


Interesting, thank you for posting that topic.


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## Robru (Jan 1, 2021)

Nice to read that they do occur in the wild. I ordered 6 in this beautiful colors.


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## Chris S (Apr 12, 2016)

Socratic Monologue said:


> @Chris S :
> 
> Most of my knowledge of inbreeding comes from reptiles, where inbreeding is done a lot, sometimes involving many consecutive generations of backcrossing and sibling pairing. Sometimes (rarely) that leads to obvious deleterious effects (i.e. clear and debilitating malformations), but those are different from the effects that would be relevant in the preservation/conservation of endangered species -- which none of us here is doing.
> 
> In fact, nearly all of the morphologically distinct characteristics that hobbyists try to increase, refine and propagate *are* deleterious, from the point of view of a wild species. Natural selection and artificial selection tend to have wildly differing, often opposing, values. Even keepers who think they are exercising some sort of natural selection (I read of a frog breeder who doesn't help new metamorphs out of the deli cup, since only the fittest should survive), but selective pressures in captivity are quite different from those in nature (the ability to climb PET plastic does not help a wild frog one bit, and is quite possibly maladaptive since some foot structures that favor climbing plastic could well be maladaptive for climbing tree bark).


These are all good, and fair points. I don't consider my fray into a hobby as something that will directly help preserve or conserve any species (not physically, maybe potentially through awareness), and I think most should try and share that similar view. I hear a lot of people talk about "saving" endangered animals through captive breeding. While this can and has be done, it should not be done at the hobbyist level. To think otherwise is actually potentially dangerous, as releasing any of these captive bred frogs as a hobbyist could actually have disastrous effects to any wild populations.

The other point I should have maybe made clear in my posts, is that I look only to preserve the natural look and "feel" of the species as best as possible. I'm drawn to this hobby (and perhaps moreso towards the Ranitomeya genus specifically) because it does not have all this backcrossing and active selective breeding stuff going on. I enjoy them as nature has evolved them to be!

Appreciate the insights,


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## tardis101 (Apr 11, 2012)

Chris S said:


> A lot of this has a ring a truth to it, and I agree with, but in the absence of any true studies on captive frogs and inbreeding/outbreeding (that I have read), the Wood Frog example is one of the best we have to pull from in regards to outbreeding.


20 years experience working exclusively with very small and endangered populations many of them frogs tells me it’s not just a “ring of truth.” It’s well documented. Just because there isn’t a specific study on captive dart frogs doesn’t make the body of studies on small populations and inbreeding depression any less relevant. The wood frog example isn’t bad, but what I’ve tried to explained is that people have glossed over (or in some cases ignored) the reason the introduction of individuals from the small population to the large one results in the large population experiencing reduced fitness. When you take a large concentration of deleterious alleles and then introduce them to a larger genetic pool you’ve just artificially and dramatically increased the concentration of those alleles in the larger population. So it’s inevitable the large population will suffer. So in this wood frog example the large population did suffer from outbreeding depression. But it did so because the population that the new genetic material came from had already experienced a nearly catastrophic genetic bottleneck and was suffering from nbreeding depression. If it had been crossed with genes from a healthy population we would have seen very different results.


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## Anda (Jan 18, 2020)

tardis101 said:


> 20 years experience working exclusively with very small and endangered populations many of them frogs tells me it’s not just a “ring of truth.” It’s well documented. Just because there isn’t a specific study on captive dart frogs doesn’t make the body of studies on small populations and inbreeding depression any less relevant. The wood frog example isn’t bad, but what I’ve tried to explained is that people have glossed over (or in some cases ignored) the reason the introduction of individuals from the small population to the large one results in the large population experiencing reduced fitness. When you take a large concentration of deleterious alleles and then introduce them to a larger genetic pool you’ve just artificially and dramatically increased the concentration of those alleles in the larger population. So it’s inevitable the large population will suffer. So in this wood frog example the large population did suffer from outbreeding depression. But it did so because the population that the new genetic material came from had already experienced a nearly catastrophic genetic bottleneck and was suffering from nbreeding depression. If it had been crossed with genes from a healthy population we would have seen very different results.


I agree with all that is being said here and forgive me if I have not understood it correctly, but I am having difficulties understanding how the outbreeding discussion relates to captive dart frogs. Most of the examples involve populations. Captive dart frogs is not "a" population it is a certain number of more or less genetically related small groups of frogs with very limited interbreeding and no uniform natural selection. While there probably are true captive-populations in larger greenhouses or in the wild in Florida, their potentially evolved traits do not apply to the terrarium animals. For there to be a "natural" selection towards viable terrarium-genes the forces creating that selection have to be present in all terrariums. And what are they? Not many I guess.
With that in mind and besides breeding as unrelated individuals as possible, is there anything else that can be done? If it can be done without ANY detrimental effect to the wild populations, would not mixing in wild genes on occasion help the main problem that is and will continue to be - inbreeding?


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## Chris S (Apr 12, 2016)

tardis101 said:


> 20 years experience working exclusively with very small and endangered populations many of them frogs tells me it’s not just a “ring of truth.” It’s well documented. Just because there isn’t a specific study on captive dart frogs doesn’t make the body of studies on small populations and inbreeding depression any less relevant. The wood frog example isn’t bad, but what I’ve tried to explained is that people have glossed over (or in some cases ignored) the reason the introduction of individuals from the small population to the large one results in the large population experiencing reduced fitness. When you take a large concentration of deleterious alleles and then introduce them to a larger genetic pool you’ve just artificially and dramatically increased the concentration of those alleles in the larger population. So it’s inevitable the large population will suffer. So in this wood frog example the large population did suffer from outbreeding depression. But it did so because the population that the new genetic material came from had already experienced a nearly catastrophic genetic bottleneck and was suffering from nbreeding depression. If it had been crossed with genes from a healthy population we would have seen very different results.


To preface: I certainly am not qualified to debate this properly, only derive from literature I have read - and learn from others like you. My experience falls solely in the captive breeding as a hobbyist, primarily frogs and fish.

My thoughts though, and incorporating what you have said above, would the following not be true (using your words, slightly modified)?: If you take a large concentration of deleterious alleles and then introduce them to a different and smaller or same size genetic pool, you will also artificially and dramatically increase the concentration of these alleles in the population. This example would be cross breeding two morphs together, for example, to try and increase genetic diversity. Obviously this depends on the "genetic" state of a captive group of frogs, and how impacted the alleles have been through any inbreeding already. 

I'll give you an example: If you cross some VERY inbred guppy strains with other, different inbred guppy strains, you often will result in offspring that have deformities, high mortality in utero, and high death rate of the fry. This is from past experience. Based on a lot of assumptions from people, one would think that in that case increasing the genetic diversity of these two guppy strains by combining them may make them more healthy, but they already have so many harmful alleles that they do the opposite.

If the small captive populations we have inevitably have some degree of inbreeding (and most certainly some have more than others), then are we not exacerbating or magnifying the issue by crossing them? In the wild some of these populations exist only in small, tiny ranges already, giving them smaller genetic pools to begin with.

The above points were sort of what I deduced from the Wood Frog study when applying it to my experience with Ranitomeya, but of course that was making some pretty larger assumptions and trying to connect many dots that should or should not be connected. 

If my understanding is way off, please let me know, and I do appreciate the context and discussion!


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## tardis101 (Apr 11, 2012)

I’m not suggesting you cross different populations (or as many refer to them as morphs or locales) per say. I’m also not saying mix the genes of the small population into the one with the greater genetic diversity because yes that would impact the genetic health of the larger population. I’m saying introduce the genes from the larger and healthier population into the smaller one. And by population in this example I mean frogs of the same morph/locale. I’m also saying to try and make sure the frogs you have are as distantly related (but still the same morph and locale) to one another as you can to minimize as best you can inbreeding depression at this point. But many people are breeding siblings and even offspring back to the parents. That is not going to help. That’s going to make it worse faster.


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## Chris S (Apr 12, 2016)

tardis101 said:


> I’m not suggesting you cross different populations (or as many refer to them as morphs or locales) per say. I’m also not saying mix the genes of the small population into the one with the greater genetic diversity because yes that would impact the genetic health of the larger population. I’m saying introduce the genes from the larger and healthier population into the smaller one. And by population in this example I mean frogs of the same morph/locale. I’m also saying to try and make sure the frogs you have are as distantly related (but still the same morph and locale) to one another as you can to minimize as best you can inbreeding depression at this point. But many people are breeding siblings and even offspring back to the parents. That is not going to help. That’s going to make it worse faster.


Sorry, I didn't mean to put words in your mouth. I was only using your words, albeit modified, within the context of the article we were discussing - I don't think you made any suggestions that would suggest you were in favour of outbreeding or inbreeding in any scenario! 

With that said, my only point was that with the already smaller genetic diversity of the captive bred populations, combined with very small populations of morphs/locales or even species in some cases, the article regarding the impact on outbreeding depression on Wood Frogs is potentially more relatable to these captive bred frogs than you may have initially indicated.


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## Socratic Monologue (Apr 7, 2018)

@tardis101 , I wonder about the equivalence between 'morph/locale' and 'population'. This two terms aren't coextensive, neither by design nor in fact.

'Locale' is generally given in reference to a politically distinct area, from something like a point locale ('Iquitos') to a country ('French Guiana'). Surely these political distinctions don't follow the contours of frog populations. 'Morph' is typically a visual distinction, which may or may not represent a distinct breeding population. Given what I've seen in taxonomic upheaval (not necessarily frogs; it is happening in reptiles) lately, it seems that basing our understanding of biological relationships on visual features is on the way out. 

The visual appearance of some (many?) dart frog locales isn't distinct, and blends into the next as one samples geographically. For example, the _Ranitomeya imitator _populations between Varadero and Sauce present as a morphological continuum, and some transitional morphotypes interbreed in the wild, and some don't.

Some natural populations have a number of visually distinct forms -- _D. tinctorius_ 'Sipliwani' is like this, as far as I understand it. Restricting captive breeding to visually similar animals would be -- if I'm correct about Sips -- tantamount to selective breeding. Simlarly -- and less contentiously -- _R. sirensis_ 'Panguana' is a highly variable intermixed population (if it is indeed one population; for me to assert this would be begging the question) in the wild, though most (all?) hobbyists keep the visual morphs "pure".

I don't put this out as some sort of _reductio ad absurdum_; quite the contrary, actually, as I think this is a pretty important topic. Any advice on how to navigate these issues?


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## tardis101 (Apr 11, 2012)

Chris S said:


> Sorry, I didn't mean to put words in your mouth. I was only using your words, albeit modified, within the context of the article we were discussing - I don't think you made any suggestions that would suggest you were in favour of outbreeding or inbreeding in any scenario!
> 
> With that said, my only point was that with the already smaller genetic diversity of the captive bred populations, combined with very small populations of morphs/locales or even species in some cases, the article regarding the impact on outbreeding depression on Wood Frogs is potentially more relatable to these captive bred frogs than you may have initially indicated.


But that’s my point. It’s not. The wood frog paper isn’t relevant here. Because in the study they introduced deleterious genes into a genetically healthy population. So what we should be doing to minimize the lack of genetic diversity is breeding one azeurus with as distantly related other azeurus as possible. Same with citronella hook up your boy frog with as distantly related citronella as you possibly can.


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## tardis101 (Apr 11, 2012)

Socratic Monologue said:


> @tardis101 , I wonder about the equivalence between 'morph/locale' and 'population'. This two terms aren't coextensive, neither by design nor in fact.
> 
> 'Locale' is generally given in reference to a politically distinct area, from something like a point locale ('Iquitos') to a country ('French Guiana'). Surely these political distinctions don't follow the contours of frog populations. 'Morph' is typically a visual distinction, which may or may not represent a distinct breeding population. Given what I've seen in taxonomic upheaval (not necessarily frogs; it is happening in reptiles) lately, it seems that basing our understanding of biological relationships on visual features is on the way out.
> 
> ...


I was just using population loosely. Probably too much so in the example I was drawing. But yes artificially creating a population from individuals that look similar is simply further restricting the genetic pool. Like spotless azeurus.


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## Chris S (Apr 12, 2016)

tardis101 said:


> But that’s my point. It’s not. The wood frog paper isn’t relevant here. Because in the study they introduced deleterious genes into a genetically healthy population. So what we should be doing to minimize the lack of genetic diversity is breeding one azeurus with as distantly related other azeurus as possible. Same with citronella hook up your boy frog with as distantly related citronella as you possibly can.


I would think it would be magnified (negatively) if you were introducing deleterious alleles into populations that already have poor genes, no?


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## Encyclia (Aug 23, 2013)

This is great stuff, guys. Thanks for taking the time to educate us, tardis. The situation that I am interested in is similar to that of the Highland Sirensis. A few years ago, it was almost impossible to get Highland Sirensis here in the US because few people were producing them. Anecdotally, people were blaming the genetics of the morph (using this term because I don't know the right term for these guys  for lack of breeding but I don't know if this is fact. Regardless, in the last couple of years, I believe people have imported some European Highland Sirensis stock and that seems to have at least partially corrected the problem. I can't imagine that the "populations" of either the US or the European Highland Sirensis were very robust genetically (though I would love to have a discussion at some point about how these little pocket populations of frogs thrive for many generations at low numbers). This is the kind of situation where it wouldn't surprise me if outbreeding depression could crop up. There are two sets of relatively limited genetic material available. Bottlenecking has probably occurred in both groups to some extent. Seems like it might go well to mix the genes, but it also might not, depending on the particular mix of genes involved. It also seems to me that if we want to preserve the frogs in the hobby (with little or no chance of ever replenishing them from the wild), we have to mix them. What are your thoughts on that situation? I am fully aware that this could be pretty far afield of your area of expertise in conservation biology since this is a very unnatural situation, but I thought I would ask, nonetheless  Again, thanks for engaging.

Mark


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## Johanovich (Jan 23, 2017)

Socratic Monologue said:


> @tardis101 , I wonder about the equivalence between 'morph/locale' and 'population'. This two terms aren't coextensive, neither by design nor in fact.
> 
> 'Locale' is generally given in reference to a politically distinct area, from something like a point locale ('Iquitos') to a country ('French Guiana'). Surely these political distinctions don't follow the contours of frog populations. 'Morph' is typically a visual distinction, which may or may not represent a distinct breeding population. Given what I've seen in taxonomic upheaval (not necessarily frogs; it is happening in reptiles) lately, it seems that basing our understanding of biological relationships on visual features is on the way out.
> 
> ...


Yeah, this was partially my earlier point as well. It is frustrating that no locality data is included in most frog morphs/locales because this could greatly improve the whole inbreeding problem. Like you said here as well, restricting animals to the ones that resemble each other even if they hail from the same original population is asking for trouble. Personally my opinion is that if the animals freely mix in the wild, I see no reason to restrict them in captivity to more stringent pairings, but without reliable data it is impossible to know this. I also find it completely baffling how for some species variability in a large population, even on a nationwide scale is considered normal and allowed to mix, whilst for other species every single differently looking/colored animal is separated out even when they occur next to each other.

Perhaps when I have access to a molecular lab again I might dive into some population genetics to figure out which frogs belong to which populations.


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## Fahad (Aug 25, 2019)

Tangential to this conversation is what I've observed with P. terribilis. Within one accepted locality type there remains a fairly signficant variation in both hue and distribution of black pigment, and even to an extent physiognomy -- to a limited degree I've seen that different frogs have different 'faces' and some are heavier set than others, etc. 

Personally, I would never attempt to line breed any of these for more of the same, but for example you can see how certain Yellow terribilis could be mistaken for Orange terribilis -- to complicate matters further, I've read anecdotal accounts that in their home range yellow and orange terribilis populations exist in close proximity to each other without significant geographical barriers, so what -- do they actually intergrade in the wild?

I of course have no idea, and I don't blame the people that know for being cagey about locality data as they'd be wanting to protect populations from poachers.

Here in Ontario I've personally discovered crazy beautiful locality types of American toads -- it's been years so I'm not sure I could even find them again -- but I'd never divulge any information about their whereabouts if I could, because there's always the threat of poachers.


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## Anda (Jan 18, 2020)

Although these frogs you are talking about have a different appearances, that does not necessarily mean they are genetically different. Phenotypic heterogeneity can also cause large variations from what I understand. Thus even breeding different looking frogs would not exclude the possibility of inbreeding. This is a general statement though, I have no knowledge how this heterogeneity manifests itself in dart frogs.


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## Fahad (Aug 25, 2019)

Anda said:


> Although these frogs you are talking about have a different appearances, that does not necessarily mean they are genetically different. Phenotypic heterogeneity can also cause large variations from what I understand. Thus even breeding different looking frogs would not exclude the possibility of inbreeding. This is a general statement though, I have no knowledge how this heterogeneity manifests itself in dart frogs.


Yes, captive populations of Yellow terribilis, for example -- are certainly inbred, to what degree being an open question, due to a limited number of founder stock. No avoiding that, but naturally line-breeding any of their phenotypes would exacerbate the issue.

Add to this that these unique dart frogs have tiny ranges in the wild; were/are they on their way out as a species even if humans weren't destroying their habitat? I don't have the knowledge to speculate realistically one way or the other.

My Blackfoots by way of Tesoros on the other hand, are F3 and almost certainly more genetically diverse. In looking for (non-experimental -- *IANAS* -- I Am Not A Scientist) any obvious differences, so far I've seen a higher early mortality rate in Mint tadpoles relative to what I've seen in Blackfoot clutches, and up to now lower breeding frequency, but there are various factors muddying the waters -- my Mints are a 4 year-old group I haven't raised from froglet. 

While they had excellent husbandry prior to coming into my hands, there remains the fact that they haven't been raised identically to my Blackfoots, are older, and have been disrupted by moving from one location to another and commenced breeding in what I'd take to be 'off-season' when the Blackfoots were winding down. Too much noise in what limited data I have so far.

Tadpole mortality notwithstanding, morphed froglets from this group appear big and vigorously healthy in terms of outward appearance. I'll be on the lookout for Mints from other populations in an attempt to shuffle the limited genetic deck. I'd love to hear from anyone who has any ideas or information on early Mint history within the hobby, I've been slowly compiling notes but the origins are foggy.


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## Robru (Jan 1, 2021)

Phyllobates terribilis population is concentrated along the upper Rio Saija drainage near Quebrada Guangui and La Brea in Colombia. Geographically isolated populations exist along the east and west banks of this river, dividing the population. P. terribilis generally has a limited range, but is abundant in that area. The typical mint white color form comes from the forests around the Rio Saija, where there is variation in color from creamy white, green white to almost gold in a population.

*Río Saij*
The Río Saija is an approximately 97 km long tributary of the Pacific Ocean in western Colombia.

*River course*
The course of the Río Saija is located in the municipality of Timbiquí in the Departamento del Cauca. The Río Saija has its source in the west of Colombia's western Cordillera at an altitude of about 500 m. It initially flows north-northwest for 20 km through the mountainous region before reaching the western low-lying coastal regions of Colombia. The river then turns to the north. At km 62 the river passes the settlement of Santa Rosa de Saija on the right bank of the river. At river 40 km, near the settlement of Boca de Patía, the Río San Bernardo meets the river that comes from the east. This then turns west-northwest. It splits twice into two arms of the river, which unite again. At river 10 km, the settlement of Puerto Saija is on the right bank of the river. Shortly after, an estuary branches north. The Río Saija eventually flows into the Pacific Ocean 10 km north of Timbiquí.
(Bolívar and Lötters, 2004; Maxson and Myers, 1985; Stewart, 2010).


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## Chris S (Apr 12, 2016)

Johanovich said:


> Yeah, this was partially my earlier point as well. It is frustrating that no locality data is included in most frog morphs/locales because this could greatly improve the whole inbreeding problem. Like you said here as well, restricting animals to the ones that resemble each other even if they hail from the same original population is asking for trouble. Personally my opinion is that if the animals freely mix in the wild, I see no reason to restrict them in captivity to more stringent pairings, but without reliable data it is impossible to know this.


There is good evidence to suggest that some animals do not freely mix in the wild (they have the ability to, but they don't). Here are a couple of articles that talk about it in a bit more in-depth. They are specific to Ranitomeya imitator, the second article is less focused on that topic though.

_"Phenotypic and Genetic Divergence among Poison Frog Populations in a Mimetic Radiation",_ Evan Twomey, et al.

"_Testing for selection on color and pattern in a mimetic radiation_", Justin YEAGER, et al.


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## Chris S (Apr 12, 2016)

Fahad said:


> Here in Ontario I've personally discovered crazy beautiful locality types of American toads -- it's been years so I'm not sure I could even find them again -- but I'd never divulge any information about their whereabouts if I could, because there's always the threat of poachers.


American Toads have an awesome range of colouration. Some of their colouration is specific to their age - younger toadlets have a more cryptic colouration. There are some fairly common morphs, such as orange and red, but to my knowledge they are not specific to a certain range. It would be interesting to see what you found!

Another such example of a small pool of genes would be certain types of Ambystoma salamanders, particularily Ambystoma jeffersonianum and laterale and their dependent Ambystoma unisexual (triploid or higher ploidy level). These exist often in small, physically isolated populations, compounded by the poaching of the male sperm by the unisexual salamanders. I imagine outbreeding depression would play a large role with these as well...but this may be going slightly off topic.


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## Fahad (Aug 25, 2019)

Chris S said:


> American Toads have an awesome range of colouration. Some of their colouration is specific to their age - younger toadlets have a more cryptic colouration. There are some fairly common morphs, such as orange and red, but to my knowledge they are not specific to a certain range. It would be interesting to see what you found!
> [...]


I've seen the orange and red amongst others, these were unlike anything I've ever seen in terms of saturation and intensity; they were actually a deep, bright pink at sub-adult and adult size. 

It was probably between 2000 and 2002 -- if I had photos (can't recall) they would have disappeared when my laptop was stolen in a break & enter a couple years later.


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## Johanovich (Jan 23, 2017)

Chris S said:


> There is good evidence to suggest that some animals do not freely mix in the wild (they have the ability to, but they don't). Here are a couple of articles that talk about it in a bit more in-depth. They are specific to Ranitomeya imitator, the second article is less focused on that topic though.
> 
> _"Phenotypic and Genetic Divergence among Poison Frog Populations in a Mimetic Radiation",_ Evan Twomey, et al.
> 
> "_Testing for selection on color and pattern in a mimetic radiation_", Justin YEAGER, et al.


Agreed, I also came across those papers concerning R. imitator and found them very interesting. I think that R. imitator is a special case because it mimics other species, which puts a pretty big selection pressure on their phenotypes even if they appear next to each other. I remember seeing some papers concerning gene flow in D. tinctorius a while back, I'll see if I can dig those up again.

But this is also why I specifically mentioned "if they mix freely in the wild", clearly for R. imitator this is not the case and apparently there is reproductive isolation:









Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator - Nature Communications


It is unclear how mimetic radiations, the evolution of a species to resemble different model species, contribute to speciation. Here, the authors show patterns of mating behaviour and genetic divergence, suggesting that mimetic divergence has promoted incipient speciation in a group of Peruvian...




www.nature.com





I did also come across this paper about Phyllobates species, which shows that there is a lot of gene flow between neighbouring populations, but less between peripheral populations (which makes sense).









Divergence, gene flow and the origin of leapfrog geographic distributions: The history of color pattern variation in Phyllobates poison-dart frogs


The geographic distribution of phenotypic variation among closely related populations is a valuable source of information about the evolutionary processes that generate and maintain biodiversity. Leapfrog distributions, in which phenotypically similar populations are disjunctly distributed and...




www.biorxiv.org





Very interesting is that they included a captive P. aurotaenia in their data and it clustered nicely with one of the wild populations.


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## Chris S (Apr 12, 2016)

Johanovich said:


> Agreed, I also came across those papers concerning R. imitator and found them very interesting. I think that R. imitator is a special case because it mimics other species, which puts a pretty big selection pressure on their phenotypes even if they appear next to each other. I remember seeing some papers concerning gene flow in D. tinctorius a while back, I'll see if I can dig those up again.


I think there are likely arguments to be made for other locale specific Ranitomeya. Certainly variabilis and fantastica show a high degree of locale specific morphs/colouration - I just don't think anyone has studied them yet, but for many other species (or maybe genus is the better term) this is likely not the case, or has not been proven to be the case anyway.


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## Tijl (Feb 28, 2019)

Ranitomeya hybrid research


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## Chris S (Apr 12, 2016)

Awesome vid Tijl!


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## tardis101 (Apr 11, 2012)

Chris S said:


> I would think it would be magnified (negatively) if you were introducing deleterious alleles into populations that already have poor genes, no?


It’s possible but usually it’s not the case. But that is part of the risk. Inbreeding tends to amplify recessive alleles because they occur in a higher concentration of the population thus increasing the likelihood of an individual ending up with two copies of the recessive genes and exhibiting the bad trait. So mixing two inbreed populations tends to improve them because it reduces the likelihood of the recessive genes being exhibited. But not always. That’s why you need to understand the genetic of the individuals you’re breeding when trying to manage small genetically limited groups.


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## Anda (Jan 18, 2020)

When perusing this forum in particular and it’s persistent focus on what is best for the frogs (which I support 100%) I can’t help but being a little surprised by the one-sided positive attitude towards breeding/breeding pairs in general. Granted I have not read the whole forum so I take this back if it has been covered earlier and Tardis mentioned it indirectly in an earlier post.
It does seem, however, that besides breeding as unrelated frogs as possible, not breeding at all would also help with the inbreeding issue. Maybe that should be added to the general recommendations on this forum?


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## Encyclia (Aug 23, 2013)

That's a really interesting point, Anda. I think it has to do with the fact that if you are going to have frogs, breeding is an important part of their behavior and folks don't want to miss out on that. However, ongoing breeding is not necessary. It is a way to offset expenses, though. I think it's something we should think more about when we are advising new people. On the other hand, not breeding doesn't _help_ the genetics of the captive bred population of frogs, it just doesn't _hurt_ the genetics. If nobody bred frogs, the hobby would be in much worse shape  

Mark


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## Chris S (Apr 12, 2016)

Maybe a larger topic of conversation, and one that should likely be split off from this one, is how to ethically and responsibly breed the frogs. It mixes with the conversation, for me anyway, in that I think for anyone looking to breed with the end result of the output being sold to other hobbyists, lineage and inbreeding/outbreeding knowledge should be a major part in this, to ensure frogs are healthy and sustainable for future captive purposes.

That said, every frog bred and sold in captivity is potentially one less frog that is smuggled from its natural environment.


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