# Mimickry vs. Hybridization?



## TimsViv (Feb 16, 2004)

There is an interesting link in a new thread in the Lounge - Website Updated! - http://www.dendroboard.com/phpBB2/viewtopic.php?t=3726 - 

On the "Dendrobates" page of Evan's link - http://personal.ecu.edu/emt0424/peru04/dendrobates.html - there are pictures of several different morphs of D. Imitator. The interesting thing is, where the D. Imitator's range overlaps with D. ventrimaculatus (Yurimaguas lowlands), the Imitators strongly resemble the vents. However, where the D. Imitator's range overlaps with D. fantasticus (Jeberos), the Imitators strongly resemble the fants.

This begs the question: Is the resemblance due to hybridization of the species or has the D. Imitator evolved to mimic the frogs that it shares territories with?

Hybridization:
Can D. Imitator cross breed with D. Ventrimaculatus and/or D. Fantasticus and produce viable offspring?
If so, what prevents the complete merger of these species into a single morph? Are there audible or visual stimulus that prevent or limit cross breeding?

Mimicry:
If D. Imitator has evolved to mimic the frogs that it shares territories with, what is the advantage of mimicking either of the other species?
Do the other species contain a more efficient toxin that prevents or limits predation?

Also, are the frogs genetically different?

Tim


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## Scott (Feb 17, 2004)

The advantage - mimicing frogs that *do* have poison in them allows the same prey avoidance that those frogs have (edit: partial points after reading Evan's post).

The Imitators differ genetically from the frogs they are mimicing. I do not know if they can (successfully) hybridize with these species though.

Evan is studying under Kyle Summers and I was at Kyle's IAD talk a couple of years ago.

s


TimsViv said:


> ...
> 
> Mimicry:
> If D. Imitator has evolved to mimic the frogs that it shares territories with, what is the advantage of mimicking either of the other species?
> ...


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## Guest (Dec 23, 2004)

I would guess that it's mimicry. I think they both could hybridize, however, for mate selection, their calls would easily separate the two. Keep in mind how when many Dendrobatids mate they male continues a short series of calls-- I would think these are species specific. Other than some Hymenoptera/Diptera mimicry, I think Dendrobatids now by far have some of the most interesting and complex mimicry of any animal. 
j


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## Guest (Dec 23, 2004)

Perhaps there's a change in either vegetation or predator's territory that selects for the brighter warning colors of intermedius in one area over the other?


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## Guest (Dec 23, 2004)

I can't speak to predators, but from what I hear they are often in stands of Heliconia, which is very difficult to get into. Perhaps, along with many other things, the color is also a deterrant that it's not worth the effort to try to get them. Possibly also the colors could mimic the flowers/seeds of Heliconia (which is less likely), but if you just see a flash or a red, orange, or yellow in a stand of them, it's something I could see being passed off.
j


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## khoff (Feb 18, 2004)

I think Justin is right on with the calls. Our imitators sound nothing like our variabilis. The variabilis sound more like our vents.


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## Guest (Dec 23, 2004)

That was another thing that I just read on his site that blew me away. I've always assumed from the literature that D. variabilis should be included with the D. imitator group (or D. vanzolinii as he states), however, calling them basically a form of D. ventrimaculatus was very interesting. I had them many years ago, and thinking back on that, it does make sense. When they reproduced, I never heard a call, nor even found the tadpoles to see how long they took to morph, but I would now venture that they are roughly the same as D. ventrimaculatus. Very interesting stuff. 
j


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## Guest (Dec 23, 2004)

Very nice topic Tim....
Kyle Summers gave a talk about the mimicry of imitator to the surrounding frog at an IAD talk a couple years ago. Have you seen this webpage before? Kyle Summers Mimicry Page



TimsViv said:


> This begs the question: Is the resemblance due to hybridization of the species or has the D. Imitator evolved to mimic the frogs that it shares territories with?
> 
> Hybridization:
> Can D. Imitator cross breed with D. Ventrimaculatus and/or D. Fantasticus and produce viable offspring?
> ...


I believe that imitator evolved along side the other species.

While intermedius were once thought to be hybrid from imitator and fantasticus, studies (maybe observations is a better word) of the tadpoles of each species revealed it wasn't. The calls of imitator are a lot different from both vents and fants. They have the nice trill, while fants produce a very quite buzz.
The advantage of mimicking the other species is protection from predation. A predator learns that a frog that looks like a fant. taste bad, so they will stay away from all frogs that look like a fant. So all fants and imitators that look alike have a better chance of living to reproduce, while the imitator that don't will have to be "sampled" to learn the effect. This is known as Mullerian mimicry... (I did a horrible job defining it sorry).


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## Guest (Dec 23, 2004)

The advantage of mimicking the other species is protection from predation. A predator learns that a frog that looks like a fant. taste bad, so they will stay away from all frogs that look like a fant. So all fants and imitators that look alike have a better chance of living to reproduce, while the imitator that don't will have to be "sampled" to learn the effect. This is known as Mullerian mimicry... (I did a horrible job defining it sorry).[/quote]

I have two questions with this. So both of them are toxic enough to avoid predation? I'm not too sure about this-- though admittedly I've never studied their toxins. My other question is what are the predators there? I think this is very important to define so we can have a better idea of what they are trying to fool and why. I would think that there would be a large difference in trying to fool some sort of bird versus a rodent. I've never read of a rodent being a predator of a Dendrobatid, but it would make a lot of sense. I think back on this past summer when Ed Kowalski and I found a ringneck snake that was eaten by some shrew in its burrow. If frogs were attacked by something like that when sleeping, how easy would that be for us to miss? A bit of rambling, but just an idea. I am most interested if anyone can share any insight into predators (if any) in that region.
j


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## Guest (Dec 23, 2004)

Yeager said:


> So both of them are toxic enough to avoid predation? I'm not too sure about this-- though admittedly I've never studied their toxins.


Well, I don't know the toxin levels of either species, but something has to be pushing them in the same direction, and predation would be the biggest key correct? Now maybe the toxin levels of the imitator are low and the other species have higher levels. That would help explain why the imitator are so diverse. If this is the case the it would be Batesian mimicry. Now maybe the levels of toxin are very low in both, and the pattern of the other frogs works as a better camouflage. I know their is one snake that can handle eating a wild terribilis, or it can withstand ver high levels of the bactrotoxin, so I am sure a the mimicry is predator induced.

This is a very good topic. It is one that make you think..


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## Guest (Dec 23, 2004)

I am most interesting now in finding out the toxicity of pretty much all the species in that region. I do remember hearing of the snake eating the P. terribilis, but I wonder in this region of Peru what is happening with predation (if present). Perhaps there is interspecific competition for habitats, and if by mimicing the more dominant frog the weaker can sneak some of the mating/deposition sites? I don't know, but I am very eager now to see this region this summer. I only hope such exciting things are happening in Ecuador...
j


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## Guest (Dec 23, 2004)

Well maybe I will get lucky and catch a picture of something eating a frog for you, while I am in Peru. Although I don't think I will be there near long enough. Hopefully you will get the time and funding to stay down there longer and figure it out! I am interested in seeing what predators have been documented in trying frog meat.


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## Guest (Dec 23, 2004)

While you are in Ecuador, note the local crab populations for me.
In the Dendrobatidae 3vol book, the author was talking about the crabs that where pretty far inland. He thought they maybe a predator to some of the Pacific populations of Histrionicus.


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## Guest (Dec 23, 2004)

Not a problem, I'll be sure to try to document that. 
j

P.S. Someone really should be Brent out of bed for this one...


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## TimsViv (Feb 16, 2004)

Yeager said:


> I can't speak to predators, but from what I hear they are often in stands of Heliconia, which is very difficult to get into. Perhaps, along with many other things, the color is also a deterrant that it's not worth the effort to try to get them. Possibly also the colors could mimic the flowers/seeds of Heliconia (which is less likely), but if you just see a flash or a red, orange, or yellow in a stand of them, it's something I could see being passed off.
> j


BGreen wrote - "Now maybe the levels of toxin are very low in both, and the pattern of the other frogs works as a better camouflage."

I would almost rule out coloration as a way of blending into the habitat, as it was noted that the Imitator were predominately found in areas of Heliconia and the Fantasticus were predominately in the areas of Bromeliads. Both could be found in the region, but each seemed to prefer a specific microhabitat.

Tim


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## Guest (Dec 23, 2004)

Yeager said:


> P.S. Someone really should be Brent out of bed for this one...


I sent him an email...about 45 mins ago


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## ETwomey (Jul 22, 2004)

To address some of the questions raised in previous posts, variabilis and imitator certainly do not hybridize. They _can_ hybridize (in captivity) but the offpspring are weird and do not seem to be viable. Also, these two frogs are equally toxic. They are Mullerian mimics. This is when 2 toxic species mimic each other to reduce the chances of being eaten by a naive predator. For example, if a naive bird eats an imitator, it will learn not only to avoid imitators but also variabilis. Now the similarities between coloration is not at all due to hybridization, but rather selective pressure to look like the other species. Interestingly, the spectrum of color variation in variabilis was matched by the corresponding populations of imitator. The mimicry motifs change as you move around Peru. The lowland imitators mimic ventrimaculatus, which, according to the most recent molecular phylogeny, is very closely related to variabilis. Imitator also mimics fantasticus, depending on where you are. There is even one spot in the Huallaga canyon where 2 different morphs of imitator are living in sympatry, where each morph is mimicking either fantasticus or ventrimaculatus. The morphs mimicking fantasticus are typically referred to as 'intermedius', while those mimicking vents are the 'yurimaguas', and the highland forms mimicking variabilis are just the regular 'nominat' form. I hope this clears some stuff up!

-Evan


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## bbrock (May 20, 2004)

I'm a little swamped today but will read through the whole thread. I'm not sure I have anything to add though. From what I can see, you guys have really covered the issues here. Nicely done!


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## chuckpowell (May 12, 2004)

This is a non-starter - they have to be mimics. No way they can be hybrids based on how species are defined. If the frogs interbreed with no barriers to prevent it then they are same species. 



TimsViv said:


> On the "Dendrobates" page of Evan's link - http://personal.ecu.edu/emt0424/peru04/dendrobates.html - there are pictures of several different morphs of D. Imitator. The interesting thing is, where the D. Imitator's range overlaps with D. ventrimaculatus (Yurimaguas lowlands), the Imitators strongly resemble the vents. However, where the D. Imitator's range overlaps with D. fantasticus (Jeberos), the Imitators strongly resemble the fants.
> 
> This begs the question: Is the resemblance due to hybridization of the species or has the D. Imitator evolved to mimic the frogs that it shares territories with?
> 
> ...


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## bbrock (May 20, 2004)

chuckpowell said:


> This is a non-starter - they have to be mimics. No way they can be hybrids based on how species are defined. If the frogs interbreed with no barriers to prevent it then they are same species.


Your right Chuck but this assumes the classification we are using is correct in the first place. Also, species lines are not always completely distinct. It's possible to have some extremely rare hybridization and still remain seperate species. The no natural interbreeding rule is more of an ideal than a real definition. Dogs have been documented breeding with wild wolves (that's for the frognetters!) but they remain separate species because the amount of genetic exchange from dogs to wild wolves is so miniscule. In other words, barriers (physical or behavioral) are not always impermeable but they may still be sufficient to allow or maintain speciation.

Maybe Evan can shed some light on this but I've felt that these frogs were part of a kind of sloppy species complex meaning they have diverged into distinct species in relatively recent evolutionary history. It seems like not only does this explain the many similarities among these species but also gives them the genetic potential to look variable and like other members of their species. In other words, because the species are related, imitator shares a LOT of genes with all the other species in their range which means that both species can converge to a similar phenotype with selective pressure. What I'm suggesting is that the mimicry may not be entirely a one-way street with imitator molding to form a phenotype that matches another species. The model actually may be having selective pressure toward the mimic as well. After all, the selective advantage is in looking alike. Other selective pressures in the local environment may have created the actual pattern. Or maybe it was just chance.

I'm glad that Evan brought up that imitator are multiple mimics - mimicking different species in different parts of their range. That was the most fascinating part of Kyle's talk at IAD in my opinion. Mullerian mimicry itself is rare enough, but has there ever been documentation of another species mimicking multiple models?

This has also been touched upon but be careful not to think about the avoidance of predation as absolute. If the frogs taste bad enough to gain any significant survival advantage, then the trait is going to be selected for. But the whole mechanism of how Mullerian mimics even form still puzzles me. So you have these two frogs and they both taste like crap so we can assume predators are avoiding both. So what is the selection that makes the frogs converge on a single phenotype? We can all see the advantage once the phenotype has become the same-predators learn to avoid both species with only one bite. So how would they get from point A to point B? Here's one possible scenario is that both species were roughly similar looking but variable in the first place. And the frogs on one end of the spectrum that looked most like their most similar counterparts on the other end got eaten less than other phenotypes. This drives the species closer together in phenotype while leaving imitator still variable enough across its range to do the same thing in a different direction elsewhere. But what kind of predation pressure would it take to do this? I mean, aren't we talking about predators who would avoid either species after learning what they tasted like? So it seems like the pressure to converge would have to come under an already low predation rate which wouldn't be that much pressure at all. In other words, the advantage gained by looking like another toxic species, while real, seems very small compared to just the advantage of being toxic. I don't know if I'm making sense but the numbers are hard to fathom.

Great thread.


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## chuckpowell (May 12, 2004)

It comes down to how you define a species, but if you assume (and I think correctly) that the frogs have to be "potentially interbreeding" to be a species and there is no barrier (biologic or physical) (which there doesn't seem to be in this case) then they are the same species no matter what they look like. Sure dogs and wolfs can interbreed but, in most cases there are physical barriers that prevent interbreeding. I think dogs are also a special case being a man-made species, presumably from a wolf or something very similar. 

Best,

Chuck




bbrock said:


> chuckpowell said:
> 
> 
> > This is a non-starter - they have to be mimics. No way they can be hybrids based on how species are defined. If the frogs interbreed with no barriers to prevent it then they are same species.
> ...


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## chuckpowell (May 12, 2004)

I'll see if I can crop the quote correctly this time. 

This sounds good and make sense but to throw another monkey-wrench into the mix - we're assuming with what evidence that all the forms are DENDROBATES IMITATOR. What if their not. You mentioned that this complex of species appears to be undergoing evolution. What if DENDROBATES IMITATOR is also, what if its a species complex unto itself and not a single species. Just a thought. 

Best,

Chuck




bbrock said:


> This has also been touched upon but be careful not to think about the avoidance of predation as absolute. If the frogs taste bad enough to gain any significant survival advantage, then the trait is going to be selected for. But the whole mechanism of how Mullerian mimics even form still puzzles me. So you have these two frogs and they both taste like crap so we can assume predators are avoiding both. So what is the selection that makes the frogs converge on a single phenotype? We can all see the advantage once the phenotype has become the same-predators learn to avoid both species with only one bite. So how would they get from point A to point B? Here's one possible scenario is that both species were roughly similar looking but variable in the first place. And the frogs on one end of the spectrum that looked most like their most similar counterparts on the other end got eaten less than other phenotypes. This drives the species closer together in phenotype while leaving imitator still variable enough across its range to do the same thing in a different direction elsewhere. But what kind of predation pressure would it take to do this? I mean, aren't we talking about predators who would avoid either species after learning what they tasted like? So it seems like the pressure to converge would have to come under an already low predation rate which wouldn't be that much pressure at all. In other words, the advantage gained by looking like another toxic species, while real, seems very small compared to just the advantage of being toxic. I don't know if I'm making sense but the numbers are hard to fathom.
> 
> Great thread.


[/i]


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## bbrock (May 20, 2004)

chuckpowell said:


> It comes down to how you define a species, but if you assume (and I think correctly) that the frogs have to be "potentially interbreeding" to be a species and there is no barrier (biologic or physical) (which there doesn't seem to be in this case) then they are the same species no matter what they look like. Sure dogs and wolfs can interbreed but, in most cases there are physical barriers that prevent interbreeding. I think dogs are also a special case being a man-made species, presumably from a wolf or something very similar.
> 
> Best,
> 
> Chuck


Okay, the same has been found with wolves and coyotes. I agree with what you are saying but I don't think we can force a definition that requires these barriers to be one hundred percent absolute. As you know, species classification is the science and are of dividing animals that often show various gradations of relatedness into discrete boxes. You can have barriers that restrict interbreeding enough to allow speciation but still have the rare oddball hybrid pairing without losing the species distinction. But I'm talking very rare events. Rare enough that they don't influence gene frequencies of either species. But I'm not a systematist so I don't know how in, or our, of vogue these concepts are right now but it has been my impression that as molecular evidence has become the tool of choice in taxonomy, then shades of gray between designated species has been recognized as common.


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## bbrock (May 20, 2004)

chuckpowell said:


> I'll see if I can crop the quote correctly this time.
> 
> This sounds good and make sense but to throw another monkey-wrench into the mix - we're assuming with what evidence that all the forms are DENDROBATES IMITATOR. What if their not. You mentioned that this complex of species appears to be undergoing evolution. What if DENDROBATES IMITATOR is also, what if its a species complex unto itself and not a single species. Just a thought.
> 
> ...


That's a really good point and interesting to think about. Suppose you have this highly variable "species" with a wide range that is sympatric with other dendrobatids in different areas of its range. Suppose this variable species is in the mid stages of speciation itself. Maybe there are semi-permeable genetic bottlenecks at multiple places throughout imitator range that creates something between population level genetic differences and full out speciation. In fact, such bottlenecks are probably a prerequisite to being able to mimic different models in different areas.

Also, we've mentioned species complexes a few times now but I'll admit that I'm not even sure what that means. I think of it as a group of frogs on different evolutionary trajectories that are just at the cusp of being full species. Maybe they are full species, and maybe they aren't. But there is at least enough genetic exchange among the group (at least recently if not currently) to make it really hard to tell if they've crossed that fuzzy line to full species. And adding another layer of confusion, not all varieties in the species complex are at the same stage of speciation so some may appear closer to an actual species break while others are closer to that population level line. I think of it like putting a bunch of blobs of different water colors on a canvas and trying to interpret the results. Some blobs remain quite distinct from each other and it is easy to tell them apart. Other blobs bleed together in the middle making it hard to tell where one ends and the other begins. Some blobs barely touch and some blobs connect with several other blobs in vairous degrees.


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## Guest (Dec 24, 2004)

Great thread.So has anyone really traced back and know whether the"lines" for the imitators we have in captivity are from the same local and were named for the people that established them in the hobby?
The one I have are from Patrick and from what he told me(correct me if I get this wrong) is his are from a Todd Kelly male and a WC female.
Some I have produced have spots and some have long black slashes.
I even now have a fine spotted one. 
The reason I am asking is I have some tads that are growing now and will be the 3rd generation from my original pair and I am thinking on adding some new "blood" to the line but I don't really know where to start.
Thanks,
Mark W.


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## Ed (Sep 19, 2004)

Hi Chuck,
There are also a number of herp species that show zones of integradation where ranges overlap yet they still remain viable species. This is probably most common in some of the North American plethodontids. 

Ed 
Ed Kowalski
South Jersey


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## chuckpowell (May 12, 2004)

Hi Ed,

My biology isn't what it should be because I'm a paleontologists and everything I work with is dead with only hard parts remaining, and those put into a geological (stratigraphic) context. That aside aren't those cases of speciation - one species becoming two, instead of two species interbreeding and producing true hybrids (as opposed to morph hybrids). If two "species" come together and interbreed with no apparent problems then I'd say they are one species. If its just occasional breeding - hybrid do exist in the wild, but interbreeding regularly would imply, to me, one species. 

Merry Christmas.

Chuck



Ed said:


> Hi Chuck,
> There are also a number of herp species that show zones of integradation where ranges overlap yet they still remain viable species. This is probably most common in some of the North American plethodontids.


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## bbrock (May 20, 2004)

chuckpowell said:


> Hi Ed,
> 
> My biology isn't what it should be because I'm a paleontologists and everything I work with is dead with only hard parts remaining, and those put into a geological (stratigraphic) context. That aside aren't those cases of speciation - one species becoming two, instead of two species interbreeding and producing true hybrids (as opposed to morph hybrids). If two "species" come together and interbreed with no apparent problems then I'd say they are one species. If its just occasional breeding - hybrid do exist in the wild, but interbreeding regularly would imply, to me, one species.
> 
> ...


Seems like I should have better things to do on Christmas but I don't. I think you are exactly right Chuck. I think the problem is that their are myriad ways that genetic bottlenecks create these varying degrees of interbreeding and thus how much of the gene pool is actually shared. That's why species classifications will never be sharply defined. The dividing line between species is a continuum and not discrete. Added to this problem is the confusion as new tools like molecular biology that come along and increase the power of being able to detect differences but along with it gets introduced new philosophy on how to divy up species. I've complained before that too much taxonomy is being determined only on the basis of statistically parsinomious differences in a small snippet of DNA and much of the ecology and natural history are being disguarded. But still, the molecular stuff is really powerful and if nothing else, it has shown us how sloppy the ecology and natural history can be regarding speciation.

Happy Festivus,


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## andersonii85 (Feb 8, 2004)

I don't have much to add here that hasn't already been said, but I felt the need to post two articles of interest:

1) Molecular phylogenetic evidence for a mimetic radiation in Peruvian poison frogs supports a Mullerian mimicry hypothesis. Symula, Schulte, Summers. Proceedings of the Royal Society of London B (2001). 268: 2415- 2421

2) Molecular systematics and phylogeography of amazonian poison frogs of the genus dendrobates. Symula, Schulte, Summers. Molecular Phylogenetics and Evolution 26 (2003). 452- 475

Anyone with access to a college library should be able to pick these up. If you really would like a copy I can make one. Just send me a pm and a few bucks to cover copying costs. 

Justin


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## ETwomey (Jul 22, 2004)

I found the PDF of one of those articles here:
http://www.journals.royalsoc.ac.uk/...l,75,181;linkingpublicationresults,1:102024,1

I could not find the other one. 

Evan


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## andersonii85 (Feb 8, 2004)

Evan,

Thanks!

That should save me a lot of time and paper...lol.

Anyone who wants to use that site just be patient as it is kind of slow to load. Also, you need Adobe acrobat reader to view it.

Justin


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## TimsViv (Feb 16, 2004)

chuckpowell said:


> This is a non-starter - they have to be mimics. No way they can be hybrids based on how species are defined. If the frogs interbreed with no barriers to prevent it then they are same species.


But that is part of the question. Can the frogs interbreed? Can D. Imitator interbreed with D. ventrimaculatus or D. fantasticus? If there is a benefit for D. Imitator to mimic D. vent or D. fant, then wouldn't there be a benefit for D. Imitator to breed with D. vent or D. fant? 

If that is the case, then can D. Imitator mimic the other frogs in other ways (ie audibally?), could D. Imitator mimic the call of D. vent or D. fant in order to hybridize for it's own benefit?

Are these frogs separate species or sub-species?

Tim


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## Ed (Sep 19, 2004)

I am a little more familar with native (to USA) species hybrids than I am to Dendrobates (now that I did a quick literature review) but there are a number of naturally occuring hybrids of broadly sympatric native anurans. These apparently do not occur with any real frequency, and in the case of hybrid males, the females of both parent species do discriminate against their calls. 
Natural hybrids have been found in Bufonidae, Pelobatidae, Hylidae, Microhylidae and Ranidae. 
If we assume that those in Bufinidae and Pelobatidae may be at least partially due to the fact that males of these families aggressively pursue any possible female and look at the other families there are still a number of breakdowns in the courtship barriers. 
These breakdowns (I am going to use Hyla to keep the list brief) are recorded in Hyla cinerea and Hyla gratiosa, Hyla chrysoscelis and Hyla versicolor (a tetraploid-diploid hybrid!!), Hyla andersonii and H. cinerea, and H. andersonii and H. femoralis. In general all of the hybridization events are due to disruptions by weather and/or ecological disturbances. 
So in undisturbed habitat the I would uspect that any hybridization would be very rare to nearly nonexistant. 

Ed


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## chuckpowell (May 12, 2004)

Can - yes, will regularily in the normal course of events - no. That's the definition of a species. And no just because their is a benefit for looking like another frog doesn't mean their is a benefit for breeding with another frog. 

I can think of many benefit for looking like different species but not for breeding with a different species. 

Best,

Chuck



TimsViv said:


> But that is part of the question. Can the frogs interbreed? Can D. Imitator interbreed with D. ventrimaculatus or D. fantasticus? If there is a benefit for D. Imitator to mimic D. vent or D. fant, then wouldn't there be a benefit for D. Imitator to breed with D. vent or D. fant?
> 
> If that is the case, then can D. Imitator mimic the other frogs in other ways (ie audibally?), could D. Imitator mimic the call of D. vent or D. fant in order to hybridize for it's own benefit?
> 
> ...


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## joshua_delancey69 (Mar 1, 2004)

I have stayed out of this because of my lack of scientific knowledge I have some books smarts but mainly first hand.. 

The Main question seems to be CAN THE SPECIES INTERBREED......I know that inbreeding is wrong and have never done it myself but for scientific purposes..............someone could mix the species male of one species female of the other and vise versa female of one and male of the other. 

0.1 Imitator X 1.0 Vent

1.0 Imitator X 0.1 Vent 

make sure that the pairs are currently breeding with each other and try it you would could never sale and may even destory before hatching but destroying before morphing would be pointless. 

This is kind of like a Hypothesis you have to TEST it...Its no good to do it for the hobby but for scientific purposes If I had some I would try it myself and post findings i think it would be intersting.....The offspring would be something i would never put in population if and when it happened but someone TEST this Hypothesis.


If I am way off base one of you guys please tell me just found this quite intersting.


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## bbrock (May 20, 2004)

joshua_delancey69 said:


> I have stayed out of this because of my lack of scientific knowledge I have some books smarts but mainly first hand..
> 
> The Main question seems to be CAN THE SPECIES INTERBREED......


Well, I don't think this is really the question at all. The old, ecologically based, definition of species was a group of animals that interbreed under natural conditions and produce fertile offspring. There are other definitions and molecular genetics has punched a lot of holes in this one but it's still a useful definition which I'm certain Chuck has been using in his arguents. And like Chuck already said, it's highly probably that these species are biophysically capable of interbreeding but that does not answer the question of how frequently this might occur in nature. So setting up a captive breeding experiment tells us almost nothing. 

I've also argued that the genetic isolation does not have to be absolute to maintain different species. In other words, a very small amount of interbreeding could occur and still keep the species functionally distinct. Here's another analogy. Suppose you have a double basin kitchen sink and you fill on with water and the other with milk. Think of these as two species and the basins are their gene pools. Everyone would agree that these are two completely separate basins of liquid. Now suppose you drilled a tiny pinhole in the divider between the two basins. What do you have? The amount of mixing would be so minimal that you would still probably consider these as a basin of water and a basin of milk. Now suppose you keep drilling the hole larger and larger at very fine increments. At what point does the hole get large enough to consider the basins as a single reservoir of diluted milk? You cannot precisely define that point which is exactly the challenge of trying to divy up variously related organisms into these neat little compartments we call species. 

The sad fact of the matter is that even if we knew everything there was to know about the breeding and genetics of these frogs in the wild, it still might come down to an educated guess and judgement call as to whether they are distinct species or not. That is the whole purpose of the field of systematics which is to apply a consistent set of rules for making these decisions. These rules tend to change as technology for detecting differences in genetics improves. But no matter how much we learn, declaring species as separate organisms or the same doesn't change their relatedness, it only changes what we call them.


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## joshua_delancey69 (Mar 1, 2004)

Thats very interesting but would not doing it in captive with a large enough viv area like a greenhouse of sorts this would allow for more natural enviroment prove weather it happens in the wild would this work? I think this has been a very interesting topic of choice..I have learned quite a bit. Thanks Guys


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## bbrock (May 20, 2004)

joshua_delancey69 said:


> Thats very interesting but would not doing it in captive with a large enough viv area like a greenhouse of sorts this would allow for more natural enviroment prove weather it happens in the wild would this work? I think this has been a very interesting topic of choice..I have learned quite a bit. Thanks Guys


Nope. "In nature" means exactly that. There are so many variables in the natural environment that you can't replicate no matter how large the greenhouse is. Weather patterns, mountain ranges, predators, and thousands more variables all play into what makes species tick. We can't even begin to understand all these variables and their countless interactions.


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## joshua_delancey69 (Mar 1, 2004)

thanks for the info this all interest me I wish I could hitch a ride with Yeager to his research site this year in feb. I would love it . 

Thanks guys for entertaining my lack of knowledge I Have gained quite a bit more in this disscussion.


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## Guest (Jan 3, 2005)

I was rereading some parts of the Christmann book tonight and did notice that he indeed had hybridized two mixes (D. ventrimaculatus x D. reticulatus and D. ventrimaculatus x D. fantasticus). They were both done in the terrarium, not in the wild.
j


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## joshua_delancey69 (Mar 1, 2004)

That book price is crazy but you all keep making me want to purchase it.. I would love to get the book to read more on that subject and many more.


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## Guest (Jan 3, 2005)

If I wasn't headed to many of the countries it coveres, I may have waited for used copies, or at least waited longer. If you have the money, it's a nice series. I enjoy the stories of finding different populations as it brings back memories. I'm sure there is a lot more charm in the original text (in German) as the author is humorous and witty at times even in the translation. I'm almost finished reading the whole set now.
j


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## ETwomey (Jul 22, 2004)

Yeager said:


> I was rereading some parts of the Christmann book tonight and did notice that he indeed had hybridized two mixes (D. ventrimaculatus x D. reticulatus and D. ventrimaculatus x D. fantasticus). They were both done in the terrarium, not in the wild.
> j


That is interesting. This sort of stuff may actually happen in the wild as well. If I remember correctly, the most recent phylogenies have the imitator clade as the most deeply sundered from the ventrimaculatus/variabilis clade and the reticulatus/fantasticus clade. Now here is something along the lines about what Justin said - The original description of the Northern duellmani may actually be a hybrid zone between reticulatus and the red ventrimaculatus, although more work has to be done to be sure. Similarly, the fantasticus we found in Pongo (see my website for pictures) bear striking resemblance to both ventrimaculatus and the standard nominal fantasticus. This may also be a hybrid zone, but since we have not sequenced their DNA this is pure speculation. Bottom line, hybrid zones may well exist between seemingly good species. Anyone going to Peru, make sure to bring a good camera and a GPS!

Evan


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## joshua_delancey69 (Mar 1, 2004)

wow that is a lot of reading.....I will not have the cash for that book at the moment I am waiting on the Professional Breeders book comming soon....I might be able to read more since i had back surgery two weeks ago I am Ruling my Couchdom and it sucks being helpless I can only lift two pounds making it hard to go to the bathroom...lol j/k


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## Guest (Jan 3, 2005)

Can you elaborate a bit on the amount of difference seen genetically between these populations (variants)? The D. quinquevittatus group really tears me with regards to grouping or splitting. I was inclined to split, but grouping at some times seems more and more appropriate. As for the camera and GPS, neither are spectacular, but will have to do for this trip.
j


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## steelcube (Mar 17, 2004)

Yeager said:


> Bgreen said:
> 
> 
> > The advantage of mimicking the other species is protection from predation. A predator learns that a frog that looks like a fant. taste bad, so they will stay away from all frogs that look like a fant. So all fants and imitators that look alike have a better chance of living to reproduce, while the imitator that don't will have to be "sampled" to learn the effect. This is known as Mullerian mimicry... (I did a horrible job defining it sorry).
> ...


Same like Justin, I kindda doubt the reason that d. imitator complex imitating a species is because predatory pressure... 

Has anyone notice any similarities between d. imitator complex and d.pumilio? 

SB


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## Guest (Sep 1, 2005)

Before I state any similarities, I would like to see more D. quinquevittatus group frogs in the wild and see behaviors. 

On the predation note, I now wouldn't be shocked to hear that some predation of Dendrobatids could be from insects-- perhaps some wasps, etc. A friend found an Atelopus sp. that was killed and eaten out completely from the stomach area. I think this has been reported with some large wasps. I also thought birds at first, but am less prone to think that now just from the pictures. I know of birds flicking at noxious organisms to eat the stomach areas.
j


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## Afemoralis (Mar 17, 2005)

*Dendrobatid depredation*

From the literature we can find examples of Motmots eating D. auratus, and Tarantulas snacking on Allobates and other dendrobatids. I can personally add snakes of the genus Liophis, as well as Cracids, and Belostomatids to the list of predators. Our froggies aren't as protected as you might think.

The point of Mullerian rings is that the level of toxicity may vary among the members of the ring, but the "model" is shared- the convergence allows for less "tasting" experiments by predators. Monarchs, Viceroys, Queens (butterflies) all share more or less the same pattern and all have some degree of distastefulness (led by the Monarch). If it is a simple Model/Mimic system it is Batesian, not Mullerian.

Cheers!

Afemoralis

.


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## Ed (Sep 19, 2004)

Another point to consider is that not all predators can see in color, notably a lot of mammalian predators, while birds and lizards can so you have to consider as to what potential predators the mimicry needs to deal with. 

Ed


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## steelcube (Mar 17, 2004)

Hah, of course... what was I thinking? the reason some animals want to mimic another is probably to avoid predation. 

I was actually thinking about the method that the imitator complex ancestor/s use to imitate other frogs color/pattern.... ie: from a plain color (maybe) to a matching color and pattern. 

Anybody have any idea?

SB


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## Ben_C (Jun 25, 2004)

Not sure if I'm understanding your question properly or not, but i'll post anyway (it's been a LONG night w/o sleep).
Anyway, the question, as I understand it is:
Do we believe that D. imitator evolved aposomatic coloration from a recent non-conspicuously colored ancestor?

If that is the question, I would wager that the answer is now simply because if we look at the basic cladograms generated for the family, the imitator complex is a more derived group within the already derived genus Dendrobates (all of whom posses bright coloration). Therefore it seems unlikely (to me) that they came from a dull dendrobates.

I hope that was the question and I hope that answered it...
~B


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## Afemoralis (Mar 17, 2005)

*Symula paper....*

The best suggestion that I can come up with is read the Symula paper- it deals explicitly with these questions and the imitator complex.

Another point to keep in consideration is that the selective pressures on the ancestral taxon may (or may not) be different from the pressures acting on the modern taxa. Who knows if the Vent pattern evolved in response to a Dendrobatid specialist that also targeted imitator? Modern systems of mimics may have little or nothing to do with modern predation- they might just be an artifact of predation in the past.

Cheers.


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## Ben_C (Jun 25, 2004)

Absolutely! I forgot to mention that...they may be artifacts from previous predation that have no reason currently to be selected out.
~B


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## steelcube (Mar 17, 2004)

No... I was thinking maybe a plain gold/yellow one since it seems to be the base color of all imitator complex.... or maybe like Corey said in another thread... it could be from something like intermedius, then developed to different patterns and colorations.

SB


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## ColombianFrogger (Jul 9, 2004)

I have to add to the predator list ants. I have seen ants atacking Atelopus, and a few days ago, a guy told me about fire ants (well, I don´t know the genus, that is how we call them here) killing histrionicus. 

I also have readed that chickens learned to eat darts in Perú, eating the stomach, so I guess many wild birds have learned this too, mainly motmots and members of the corvidae families. They are very, very smart and learn how to do the things. I once saw a Cyanocorax (corvidae) catching wasps, but first he drowned the wasps in water and after that, eat them. So I have no doubts they can learn how to eat poison frogs...


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