# Azureus x inferalanis Hybrids



## Irfin (Dec 15, 2009)

I have a proven Azureus pair that I housed with an Inferalanis and I accidentally reared hybrid babies. The variety is interesting and I plan to continue exploring the inheritance of the various traits by continuing cross-breeding experiments. Please enjoy these pictures.

This is not a trolling attempt. From my research on the forum it's clear people have strong opinions about the ethics of cross-breeding. It also became clear that some people seem to post about strange morphs of accepted sub-species. I suspect these are all hybrids as I don't believe that people know as much about the origin of their frogs as most would like to believe.

It also appears that some of the traits are recessive so even suspected pure-breed azureus could be hybrid carriers of other genotypes that could be expressed in future generations.

Other threads suggest that commonly accepted sub-species and species designations are not as concrete and substantiated as some community members might believe and express. One specific example is the distinction between the inferalanis in the US vs Europe.

I'd be interested to hear about and see other hybridization accidents or attempts. Specifically with azureus and related tinctorius sub-species.


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## Frog pool13 (Oct 30, 2013)

I dont necessarily agree with your opinions on hybridization, but it is sometimes interesting to see what turns out when you do interbreed them.


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## Irfin (Dec 15, 2009)

Another interesting aspect of this event is that the inferalanis must have deposited sperm after the proven azureus pair finished their mating behavior. We never observed the male inferalanis interacting with the female or displaying courting behaviors.

I wonder how many community members are aware that other males who share a habitat with a proven pair can contribute their genetic material after the completion of copulating behavior by a proven pair, because the eggs are fertilized externally. I suspect this has a lot to do with the variation people see in their "pure blood-line".

Unless the pair is isolated from all other frogs, I suspect people's certainty about genetic lineage is compromised by the presence of other males.


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## Boondoggle (Dec 9, 2007)

While I don't have much to add to the hybrid discussion I do sincerely appreciate your being public and honest about it. 

I would hesitate to come to the same conclusions on the parenthood that you have come to, though. Just because you "never observed the male inferalanis interacting with the female or displaying courting behaviors" doesn't mean it didn't happen. In fact its much more likely that it happened without your notice than that a lone male came and ejaculated on a prefertilized jelly mass after the fact, sans any courting behavior.


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## Scott (Feb 17, 2004)

Accidentally?

The frogs were in the tank together - they're going to do what they're going to do.

No accident.

s


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## oldlady25715 (Nov 17, 2007)

DFW alert! Rick is that you?


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## Scott (Feb 17, 2004)

DFW doesn't need to be on this thread please. They have their own thread.

Let's not put them EVERYWHERE please.

s


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## toostrange (Sep 19, 2013)

I for one do not house my diff morphs together. That way there is no "accidents". If one has done their research they know that's what happens. I'm in agreement that an experienced frog keeper would know this and wouldn't call it an "accident". It is what it is.


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## Baltimore Bryan (Sep 6, 2006)

Irfin said:


> Another interesting aspect of this event is that the inferalanis must have deposited sperm after the proven azureus pair finished their mating behavior. We never observed the male inferalanis interacting with the female or displaying courting behaviors.


I'm pretty sure males actually deposit sperm before the female lays the eggs, so this would not be a true assumption.



Irfin said:


> It also became clear that some people seem to post about strange morphs of accepted sub-species. I suspect these are all hybrids as I don't believe that people know as much about the origin of their frogs as most would like to believe.
> 
> It also appears that some of the traits are recessive so even suspected pure-breed azureus could be hybrid carriers of other genotypes that could be expressed in future generations.


Why do you suspect these are all hybrids considering many populations naturally express some variation in pattern? I'm just not sure how you can make an assumption like that, unless you are talking about frogs that look drastically different than the parents (like totally different color patterns?)

I'm also not sure what you mean by some suspected "pure-breeds" being carriers of recessive hybrid genes. This is not a simple dominant and recessive genetics case where, for example, a pair heterozygous "azureus" would throw 25% of the recessive "cobalt" morph (doesn't happen). 
So what kinds of hidden traits do you mean? Have you experienced azureus pairs producing a percentage of frogs with yellow legs or something like that?

Bryan


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## Irfin (Dec 15, 2009)

Baltimore Bryan said:


> I'm pretty sure males actually deposit sperm before the female lays the eggs, so this would not be a true assumption.
> 
> 
> 
> ...


http://www.dendroboard.com/forum/me...1849-cool-looking-azureus-morphing-out-2.html


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## srrrio (May 12, 2007)

Not particularly interested in your crosses. However your substrate looks very wet and whether crosses or pure, I am sure they would like some nice cozy leaf litter,


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## Irfin (Dec 15, 2009)

Baltimore Bryan said:


> I'm pretty sure males actually deposit sperm before the female lays the eggs, so this would not be a true assumption.


ADW: Dendrobates tinctorius: INFORMATION

Amplexus occurs always on land, never in water. Eight to ten eggs are laid and the male ejaculates the sperm directly over the eggs. The male will carry the nearly hatched tadpoles on his back to water. There tends to be considerable sibling aggression among the larvae. (Obst, 1988) Dozens of tadpoles may be placed in one large water hole by several males. Tadpoles reach transformation size in about ten weeks and feed on almost anything. (Walls, 1994)

Obst, F. 1988. The completely illustrated atlas of reptiles and amphibians for the terrarium. Neptune City, NJ: T. F. H..

Walls, J. 1994. Jewels of the rainforest. NJ: THF.

http://intraweb.stockton.edu/eyos/page.cfm?siteID=89&pageID=60

Typical amplexus* found in other frog species is absent here. Instead, one of the frogs, enters the bower alone. Typically, the female enters first and deposits eggs. After she leaves, the male will enter the bower and fertilize the clutch. A variation of this occurs when the sperm is deposited on the leaf first upon which the female lays her eggs.


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## Irfin (Dec 15, 2009)

Baltimore Bryan said:


> I'm also not sure what you mean by some suspected "pure-breeds" being carriers of recessive hybrid genes. This is not a simple dominant and recessive genetics case where, for example, a pair heterozygous "azureus" would throw 25% of the recessive "cobalt" morph (doesn't happen).
> So what kinds of hidden traits do you mean? Have you experienced azureus pairs producing a percentage of frogs with yellow legs or something like that?
> Bryan


My long term goal would be to develop some data about dart frog genetics with @home biohacking. For now I'm interested in the unexpected results I received. 

Accident, no accident, it wasn't my initial intentions. However, now that I'm down this road, I'm interested to see what research has been done about dendrobates tinctorius genetics.

Here's some light reading from scholarly resources (maybe they'll move me from beginner back to general discussion):

Characterization of ninepolymorphic microsatelliteloci in the dyeing poisonfrog
Dendrobates tinctorius (Dendrobatidae), and their cross-species utility in two other dendrobatoid species

http://homepage.univie.ac.at/eva.ringler/papers/Ringler et al 2012 HerpJ.pdf

Refugial isolation and secondary contact in the dyeing poison frog Dendrobates tinctorius.

Refugial isolation and secondary contact in the dye... [Mol Ecol. 2006] - PubMed - NCBI

"Phylogenetic, nested clade, and dispersal-vicariance (DIVA) analyses of cytochrome b sequence data reveal the presence of two mitochondrial lineages that are associated with previously identified western and eastern uplands of this area. The geographical distribution of mitochondrial haplotypes and the results of DIVA and coalescent analyses suggest that there has been extensive secondary contact between these lineages indicating a complex history of connectivity between these western and eastern highlands, supporting the predictions of the DV hypothesis."

Hypotheses to explain the origin of species in Amazonia.

Hypotheses to explain the origin of species in A... [Braz J Biol. 2008] - PubMed - NCBI

"The main hypotheses proposed to explain barrier formation separating populations and causing the differentiation of species in Amazonia during the course of geological history are based on different factors, as follow: ... (7) competitive species interactions and local species isolations in peripheral regions of Amazonia due to invasion and counterinvasion during cold/warm periods of the Pleistocene (Disturbance-vicariance hypothesis)

Phenotypic and Genetic Divergence in Three Species of Dart-Poison Frogs With Contrasting Parental Behavior

"We suggest that strong sexual selection associated with female parental care in D. pumilio, which contrasts the male parental care of P. lugubris and Minyobates sp., may have driven divergence in coloration and pattern in D. pumillo."

Interesting mitochondrial DNA anaylsis between sub-speices of related dart frog species where sexual selection is a suggestion for variation.

I understand these papers and can read the language because I have a degree, background and job in science. I think they are an interesting start for future exploration.


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## PDFanatic (Mar 3, 2007)

You are fighting a losing battle....Those frogs aren't even the slightest bit neat looking.


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## Boondoggle (Dec 9, 2007)

Irfin said:


> I understand these papers and can read the language because I have a degree, background and job in science.


Well that is impressive.


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## Irfin (Dec 15, 2009)

Boondoggle said:


> While I don't have much to add to the hybrid discussion I do sincerely appreciate your being public and honest about it.
> 
> I would hesitate to come to the same conclusions on the parenthood that you have come to, though. Just because you "never observed the male inferalanis interacting with the female or displaying courting behaviors" doesn't mean it didn't happen. In fact its much more likely that it happened without your notice than that a lone male came and ejaculated on a prefertilized jelly mass after the fact, sans any courting behavior.


An interesting article about another frog species:

Unusual amplexus in Dendropsophus columbianus

http://www.herpetologynotes.seh-her...os_Herpetology_Notes_Volume5_pages497-498.pdf

(Most people can figure out the language of this one, though it's still sciency. Pretty much the males are sex crazy and will do anything with anyone or anything. DFW.)

I continue to look for resources about multiple male external and delayed fertilization about dendrobates but have yet to find something specific.

My last question for the night:

What is the purpose of waiting after a female has laid her eggs in order to ensure they are fertilized before pulling them from the habitat? Does this not imply that there is a delay between egg laying and sperm delivery? And does this not then suggest that other males could contribute their sperm without amplexus?

Aquatic eggs are fertilised by multiple males not engaged in amplexus in a stream-breeding frog

Aquatic eggs are fertilised by multiple male... [Behav Processes. 2012] - PubMed - NCBI


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## ZookeeperDoug (Jun 5, 2011)

Irfin said:


> I wonder how many community members are aware that other males who share a habitat with a proven pair can contribute their genetic material after the completion of copulating behavior by a proven pair, because the eggs are fertilized externally. I suspect this has a lot to do with the variation people see in their "pure blood-line".
> 
> Unless the pair is isolated from all other frogs, I suspect people's certainty about genetic lineage is compromised by the presence of other males.


Fallacious assumptions. Most members are fully aware of these issues which is why they do not irresponsibly house different morphs, locales, or bloodlines together. They do this specifically to avoid the unfortunate "accident" you claim has happened. You've been a member since 2009, you should also be fully aware of these problems. I suspect you did this intentionally and are presenting the idea as an accident to avoid accountability. The real question is which is worse, creating hybrids due to ignorance or on purpose? There really is no excuse for either.


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## rigel10 (Jun 1, 2012)

I do not understand why you try to justify on a scientific basis this "accident", if it was an "accident."


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## Irfin (Dec 15, 2009)

ZookeeperDoug said:


> Fallacious assumptions. Most members are fully aware of these issues which is why they do not irresponsibly house different morphs, locales, or bloodlines together. They do this specifically to avoid the unfortunate "accident" you claim has happened. You've been a member since 2009, you should also be fully aware of these problems. I suspect you did this intentionally and are presenting the idea as an accident to avoid accountability. The real question is which is worse, creating hybrids due to ignorance or on purpose? There really is no excuse for either.


I was even referring to multiple males of the same sub-species producing "pure-bred" frogs but sired from multiple fathers.

People in this forum community have an irrational emotional response to the idea of mixing sub-species when if they looked at the scientific, scholarly research, they will find that what they assume about their "pure blood-lines" isn't true in nature, not to mention when they obtain captive bred frogs from internet, regardless of the reliability and reputation of the source.

Science doesn't even classify these animals as different species.

Though I did not make these hybrid intentionally, I will from now on and I will continue to post my results on this forum for people to write short, unthoughtful responses about my character as a person that don't add to the conversation.

If you respond with a counter argument, at least have the courtesy of citing you information. There seem to be a lot of psuedo-experts on this forum who like to make big claims without supporting evidence.


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## Irfin (Dec 15, 2009)

rigel10 said:


> I do not understand why you try to justify on a scientific basis this "accident", if it was an "accident."


My scholarly resources are not being used to justify the original event, but rather to justify my interest in crossing sub-species now that I have done so for the first time.

I knew full well that this could have happened but expected my proven pair was established enough that it wouldn't allow for the inferalanis to contribute. I was clearly wrong and am also interested in how he did contribute his sperm to the eggs.

Last, if I wanted to _*eat *_my frogs, that's my pejorative. No one has a right to say what I can or can not do with my animals. People can live in your ivory tower and scream about frog-Eugenics all day long. 

Eventually people like me are going to play with the genetics through artificial selection (as I believe most people are without knowing it because they don't know as much about the origin of their animals as they think they do).

The community can be open to it, and therefore have the information presented to them with full disclosure. Or the community can remain closed-minded to these ideas. Just because you don't hear or see the conversation doesn't mean it's not happening.


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## Dev30ils (May 1, 2012)

Irfin said:


> I knew full well that this could have happened but expected my proven pair was established enough that it wouldn't allow for the inferalanis to contribute.


You realize frogs aren't like some birds, right? They don't mate for life.


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## Irfin (Dec 15, 2009)

Dev30ils said:


> You realize frogs aren't like some birds, right? They don't mate for life.


Thanks for the well-thought comment. Do you have evidence to support your statement or are you just making this up? What is your source other than your conjectures related to your statistically insignificant personal experiences caring for dart frogs?

You don't know if they do or do not mate for life and neither do I.


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## rigel10 (Jun 1, 2012)

Regarding your previous post, I think it is a pointless question. In our viv "Nature" is not involved. We are there to substitute her. You may not agree, but in fact we will substitute her. For this, I think, we should act in a responsible manner.
Just add this and then I'm out of this discussion, giving way to people more expert in the English language.
At least once a month, a thread is opened about hybridization giving scientific justification or stating that this has happened by accident. If it was an accident - and everyone can make mistakes - I think we need to make amends, present to others hybrids as curiosity and breeding these hybrids without hope of being able to put them on the market.
A serious seller never sell hybrids, even if they were born by accident.
Let's me to be clear! I'm not accusing you of anything. You can do what you want with your frogs. But you spoke of an accident above and now you're turning the omelette, as we say here, speaking of scientific experiments. 
If you made a mistake by mixing frogs and you've got hybrids, enjoy them! You can also continue your study about them. But no one can claim that someone here - at least most of us - can tell you who did well to hybridize frogs.
I hope I explained myself and I apologize for my poor English.


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## Tyler Jones (Nov 4, 2009)

Irfin said:


> My scholarly resources are not being used to justify the original event, but rather to justify my interest in crossing sub-species now that I have done so for the first time.
> 
> I knew full well that this could have happened but expected my proven pair was established enough that it wouldn't allow for the inferalanis to contribute. I was clearly wrong and am also interested in how he did contribute his sperm to the eggs.
> 
> ...


What are you trying to accomplish by knowingly (or accidentally) cross-breeding your frogs?


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## Irfin (Dec 15, 2009)

Tyler Jones said:


> What are you trying to accomplish by knowingly (or accidentally) cross-breeding your frogs?


I would like to learn more about tinctorius genetics. I intend to collect scholarly articles and present them at a later point.

One of my intentions is to show that most people don't know the origin of their frogs and that their supposition of blood-line purity is an emotionally derivative of their reading and agreeing with non-expert postings on this forum.

But on a very basic level, I want to explore an area this hobby that apparently most people have not. And the fact that people are so against it makes it all the more interesting to me.


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## jdart16 (Jun 5, 2008)

Just a few questions and clarifications.

First by learn more about tinc genetics what exactly do you wish to learn through the breeding? It seems to me that the only conclusions that could be drawn would be observation of the expressed phenotype unless you plan on genetic analysis? As far as observing the phenotype what is gained from it? There is no control to compare with, and they are observations in variations in some cases may not even be a product of crossing locals. (ie a azureus with larger spots may be natural variation rather than a mix). I'm just confused exactly what the experiment contributes to the hobby.

Second i'm a little confused, are you saying the froglets that look like azureus in the pictures are crossed frogs expressing a dominant or recessive gene making them look more like azureus? If so based on what? It is entirely possible the other male had no interaction with the azureus pair which led to a "pure" azureus and not an expression of mixed local genes.

Thanks for your time, Justin


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## ZookeeperDoug (Jun 5, 2011)

Irfin said:


> People in this forum community have an irrational emotional response to the idea of mixing sub-species when if they looked at the scientific, scholarly research, they will find that what they assume about their "pure blood-lines" isn't true in nature, not to mention when they obtain captive bred frogs from internet, regardless of the reliability and reputation of the source.


Ok Spock! You're not really presenting anything new here and you're not due anything other than a non emotion response. Basically we're just laughing you off like the last guy who came along trying to stir the pot and rehash the same tired old arguments about hybrids. The science has been hashed, and rehashed, stuffed into a horse, that was then shot, brought back to life, beaten, hung till dead and then beaten some more for good measure. And you're well aware of all this as clearly evidenced by this post. You knew exactly the kind of response you would get, in fact, I suspect that was your intent.



> Science doesn't even classify these animals as different species.


 Something were all aware of. Unfortunately you're missing the entire point. You know full well it isn't about species.



> Though I did not make these hybrid intentionally, I will from now on and I will continue to post my results on this forum for people to write short, unthoughtful responses about my character as a person that don't add to the conversation.


That didn't take long. The proverbial, well I'm gonna do it now just to spite you response was certainly predictable, although I'll admit, I didn't figure you'ld play that card this early.

Please, by all means, keep posting. Forgive me if I don't rush off to get my popcorn and watch the fireworks as I suspect you'll be dealt with the same way as every other person trying to stir up this nonsense has been dealt with.



> If you respond with a counter argument, at least have the courtesy of citing you information. There seem to be a lot of psuedo-experts on this forum who like to make big claims without supporting evidence.


Don't try to pretend that you don't know already what the counter arguments already are. They've been made and the evidence presented countless times before, and there is no reason for us to rehash them again just for you.


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## Kuhny11 (Aug 30, 2013)

I'm fairly new to this so please don't attack me too harshly but I don't understand why cross species breeding is looking down upon so harshly while inbreeding siblings and parent/offspring frogs seems like it is regularly accepted. Won't both cause problems? Why is one so much worse than the other?


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## Dendro Dave (Aug 2, 2005)

Irfin said:


> I have a proven Azureus pair that I housed with an Inferalanis and I accidentally reared hybrid babies. The variety is interesting and I plan to continue exploring the inheritance of the various traits by continuing cross-breeding experiments. Please enjoy these pictures.
> 
> This is not a trolling attempt. From my research on the forum it's clear people have strong opinions about the ethics of cross-breeding. It also became clear that some people seem to post about strange morphs of accepted sub-species. I suspect these are all hybrids as I don't believe that people know as much about the origin of their frogs as most would like to believe.
> 
> ...


Ok first, we actually do know where a lot of the founder stock of many frogs came from. A lot of history is documented on this forum and else where. I'm not up on it all as much as some of the real old timers, but the info is out there and it is the basis for many of our "lines", like "Ranitomeya amazonica (Todd Kelly line)".

Second, I can't speak for everyone, or give you a percentage, but I know many if not most of us read at least 1 or 2 books on dart frogs and, somehow I was made aware that males may fertilize eggs deposited by females and part of the clutch fertilized by other males since my first months or at most year or two in the hobby. I thought that was fairly common knowledge. 

As long as the 2 frogs are of the same species/morph/locality (or we're pretty sure at least)... Like say 1 male oyapock tinc fertilizes eggs from 2 unrelated females, maybe the male is related to one of the females or not... They are still considered "pure blood" because they represent the "oyapock" locale/morph, or in some cases import year, or a specific line. They don't have to be related, in fact we actively encourage crossing some frogs, like for instance the Benedicta that came in from Understory. 

Everyone who got those likely ended up with mostly unrelated, or at least fairly unrelated frogs. Due to the small population/limited distribution there is probably frogs that are pretty closely related, but we do the best we can, so we encourage getting a few from one guy and breeding those to a few from another guy. Sometimes that is difficult/impractical, and these guys have shown themselves capable of remaining viable even with limited founder stock for many generations (which may = decades in the hobby), so for the most part we don't crucify someone if they buy a group of related frogs, breed them and sell them, because at the very least as those frog spread throughout the hobby they are going to encounter and breed with groups of unrelated, or at least less related individuals... at some point.

It isn't the ideal, but given the difficulties involved in pairing up the most unrelated frogs, and getting the majority of people onboard to do it consistently, I think it is about the most we can expect. We keep some lines/localities/import years separate usually because we either know, or aren't quite sure if it is they are the same as other frogs in the hobby. For instance, superblues are very similar to highland auratus, but the best info we have says even though these frogs are very similar they are in most likely different populations, other frogs we aren't so sure about. Like the green aurotaenia coming in from the Tesoros project. They seem to look just like the old line that has been in the hobby for years, but maybe they represent a geographically separate population. We don't know, but the majority of us it seems want frogs that are as representative as whatever population the founder stock came from as possible. 

Doing this is* in part* how we limit the damage/uncertainty imposed on us by people creating hybrids, or unknown lines being mixed with known lines, etc..etc... It's at least as much a logistical issue as it is an ethics issue, IMO at least. We are basically trying to keep things straight, so that the majority of people can go purchase an Azureus, or an Oyapock, an auratus etc...etc... and be reasonably sure that what they get is actually of the species/morph/locality that they wanted... and will likely breed true with only some minor variation, maybe the occasional albino or other aberrant frog. 

It's entirely possible that at some point either in the wild, or in captivity many of our frogs have had some DNA injected into the line from another species and/or another morph. For the most part we'll never know, but what we do know is that most of our frogs breed true with some slight variation or represent the substantial variation that its wild counter parts display, and maybe occasionally a very aberrant frog pops up... much like you'd see in the wild. Are all the genetic possibilities of their wild counterparts accounted for? Unlikely, but we have a relatively small number of founder stock in many instances. Again, we do the best we can, or in the ballpark at least. *People creating and releasing hybrids, or even loosing the origin info of their frogs undermines that effort and effects all of us. * We cope by either pretty much letting some CB frog populations slowly fade away, or at least only breeding them to other unknown frogs that seem best we can tell very very similar. *Again, people going against that undermine our efforts, and inject more risk/uncertainty into the hobby. There are feelings and real money involved here, even lively hoods at stake.*

To say something like... *"I suspect these are all hybrids as I don't believe that people know as much about the origin of their frogs as most would like to believe."* ...seems a rather large leap for a trained scientist to make, but let's give you the benefit of the doubt and call it a "hypothesis"... Ok, what do you hope to accomplish? You do know that scientists have already done hybridization experiments with many of these frogs, right? What are you going to do with the frogs you produce? Are you going release a bunch of hybrids into the hobby, info about which will likely be lost, significance not realized, or hidden due to the stigma thus muddying the waters of our hobby? Do you understand that what you do does not happen in a vacuum, and that once those frogs leave your hands they potentially effect the entire community? What if your family sells or gives them away because you are sick or something worse happens? How do you rationalize/justify satisfying your curiosity and/or selfish desire if/when something like this happens? You are in effect asking us to trust you. Why would we when you've already stated a position that is counter to ours? What if some unknowing and/or unscrupulous person gets them, realizes they are hard to sell because most of us don't want hybrids, and decides to hide the fact to make some money back, or at least get their money back when they realize the stigma attached to theses frogs? You might be cool, but not everyone is and cool or not what you do gives other people more opportunity to screw up our hobby at least for many of us, if not the majority. 

Anyways, my point is that regardless of the ethics of "frog eugenics", there is an almost certainty that what one or a few do out of curiosity, or their own selfish desires to have an oddball frog is going to eventually effect the entire hobby community, cause a lot of confusion and turn our hobby into something similar to the leopard gecko or parts of the snake hobby, where good luck trying to find an animal that is representative of a wild population and breeds fairly true to that population. Honestly we probably can't stop it from happening eventually, but the slower it happens the better shot we have of keeping populations that are fairly representative of their wild counter parts separate from the hybrid/designer frog part of the hobby. *How do you justify being the guy who speeds up what many if not most consider a tragedy?*

For me it is a question of the ethics/morality of a minority imposing their will onto the majority, because the simple fact is other then the logistics we have in place and some peer pressure we can't stop you... But *how do you justify to yourself making sure you get what you, or a few want over the vast majority of other froggers? *If you can conduct your experiments in a vacuum, guaranteeing that there will be no more risk to me and many others here of uncertainty when it comes to what we want to keep and spend money on... that a frog I want to buy is in fact the frog I get, and you will actually produce some real scientifically valid/publishable results then ok, but otherwise *can you explain to me how this isn't you just basically saying "what I want is more important then what the majority wants... Screw them I'm doing what I want?*

*P.S.* I find hybrids/pics of hybrids fascinating, I even think some are very cool looking... But I don't do it, because IMO I don't have the right to tell all these other people to go screw themselves to satisfy my own curiosity or personal selfish desire to have some oddball frog. *How/Why do you find doing so acceptable?*


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## swampfoxjjr (Nov 13, 2007)

Irfin said:


> Last, if I wanted to _*eat *_my frogs, that's my pejorative.


pe·jo·ra·tive
adjective
1.
expressing contempt or disapproval.

noun
1.
a word expressing contempt or disapproval.

pre·rog·a·tive
noun
1.
a right or privilege exclusive to a particular individual or class.

Sometimes, the universe has a lovely way of expressing irony. OP, I'd hate to be pejorative about your needless foray into the world of hybrid dendrobatids, but, I suppose, it's my prerogative to do so.


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## Gamble (Aug 1, 2010)

It's people like this & the seeming frequency this kind of thing has been occurring lately, that I know of quite a few people who are leaving this hobby.

I personally feel, that while things like FB have helped to bring this hobby into a more mainstream awareness when animals are kept, it's also become the hobbys own worst enemy.

I personally enjoyed this hobby much more before social media became the giant it is today.

This is just another example.


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## Ed (Sep 19, 2004)

Gamble said:


> It's people like this & the seeming frequency this kind of thing has been occurring lately, that I know of quite a few people who are leaving this hobby


Well people do get tired of seeing the same old arguments being trotted out to support a person's decision to hybridize particularly when it's deliberately presented in a way designed to cause a fire storm... I know I'm pretty tired of it. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Kuhny11 said:


> I'm fairly new to this so please don't attack me too harshly but I don't understand why cross species breeding is looking down upon so harshly while inbreeding siblings and parent/offspring frogs seems like it is regularly accepted. Won't both cause problems? Why is one so much worse than the other?


Yes they both can cause issues however the risks to the captive population are not the same. Hybridizing or crossbreeding can result in what is known as outbreeding depression which can take as much as 5 generations to cause issues. The main thing to remember is that outcrossing within a specific population can be used to resolve inbreeding depression... you cannot correct outbreeding depression. There are a lot of discussions on this topic including references to the literature on the risks and problems. 
See if you can track down a free access copy of Between a rock and a hard place: evaluating the rel... [Mol Ecol. 2007] - PubMed - NCBI 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Irfin said:


> I would like to learn more about tinctorius genetics. I intend to collect scholarly articles and present them at a later point.


And what methods are you planning to use for this study? How are you controlling for various issues such as outbreeding depression? 



Irfin said:


> One of my intentions is to show that most people don't know the origin of their frogs and that their supposition of blood-line purity is an emotionally derivative of their reading and agreeing with non-expert postings on this forum.


You do realize that crossing two populations isn't going to demonstrate this right? At the outset, I'm going to have to throw the BS flag for this claim... 



Irfin said:


> But on a very basic level, I want to explore an area this hobby that apparently most people have not. And the fact that people are so against it makes it all the more interesting to me.


And you could have done it without trotting it out on the forum to create a firestorm as opposed to how your proceeding with it.... 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Irfin said:


> Thanks for the well-thought comment. Do you have evidence to support your statement or are you just making this up? What is your source other than your conjectures related to your statistically insignificant personal experiences caring for dart frogs?
> 
> You don't know if they do or do not mate for life and neither do I.


Actually if you bothered to follow the literature, it is very clear that the vast majority of dendrobatids including D. tinctorius are not monogamous in the very least... 

This has been documented in the literature. The fact that you chose to not do the research should not in anyway require another person to do that work for you... 

I'm going to give you a suggestion on where to start.... the link works... JSTOR: An Error Occurred Setting Your User Cookie 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Irfin said:


> My scholarly resources are not being used to justify the original event, but rather to justify my interest in crossing sub-species now that I have done so for the first time.


First off, if your making claims as to it being for a scientific paper, then you should really demonstrate that you understand the science first.. in this case, your demonstrating ignorance because your inflating a population designation as being the same as subspeciation. This is not the case. I would suggest that you reorient your "scholarly resources" into learning the basics of the taxa your claiming your going to study. 



Irfin said:


> I knew full well that this could have happened but expected my proven pair was established enough that it wouldn't allow for the inferalanis to contribute. I was clearly wrong and am also interested in how he did contribute his sperm to the eggs.


And your now indicating that you have no understanding of how courtship works in dendrobatids. I would suggest that you check out the link I provided above as a start for educating yourself. I would also suggest researching the interaction between nutrition and egg production... 



Irfin said:


> Last, if I wanted to _*eat *_my frogs, that's my pejorative. No one has a right to say what I can or can not do with my animals. People can live in your ivory tower and scream about frog-Eugenics all day long.


How about scientists being horribly insulted by your claims that this so called "experiment" is going to result in any worth while data? Can we enunciate our disapproval? I can tell your for a fact that your study is not publishable in any respectable journal. It wouldn't even get to the peer reviewed process as the editors would reject it out of hand. 



Irfin said:


> Eventually people like me are going to play with the genetics through artificial selection (as I believe most people are without knowing it because they don't know as much about the origin of their animals as they think they do).


I threw the BS flag on this earlier and I reiterating that it needs to be thrown here again... 



Irfin said:


> The community can be open to it, and therefore have the information presented to them with full disclosure. Or the community can remain closed-minded to these ideas. Just because you don't hear or see the conversation doesn't mean it's not happening.


And you just made the ideal argument why you didn't have to bring it to the forum to create a firestorm.... 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Irfin said:


> Another interesting aspect of this event is that the inferalanis must have deposited sperm after the proven azureus pair finished their mating behavior. We never observed the male inferalanis interacting with the female or displaying courting behaviors.


Okay, you don't understand how this works in dart frogs... I suggest researching how fertilization occurs with frogs... you may want to look up how the mucopolysaccharides can help or impede fertilization as well as when fertilization actually occurs. 

Second, all because you saw courtship between the same population animals doesn't mean that the female can't change her mind.... 



Irfin said:


> I wonder how many community members are aware that other males who share a habitat with a proven pair can contribute their genetic material after the completion of copulating behavior by a proven pair, because the eggs are fertilized externally. I suspect this has a lot to do with the variation people see in their "pure blood-line".


Um.... no. You really have no understanding here... within populations there is genetic variation... and there have been studies done on it contrary to your idea... you might want to check out the pictures documented by Zimmerman and Zimmerman. 



Irfin said:


> Unless the pair is isolated from all other frogs, I suspect people's certainty about genetic lineage is compromised by the presence of other males.


And again, no... the only way the genetic lineage would be compromised is if people house different populations/species together. Multiple males of the same populations do not compromise lineages. 

Again, self education before making accusations is the best option. This stuff has been discussed before just maybe not in simple language. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Baltimore Bryan said:


> I'm pretty sure males actually deposit sperm before the female lays the eggs, so this would not be a true assumption.
> 
> Bryan


Correct! 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Irfin said:


> ADW: Dendrobates tinctorius: INFORMATION
> 
> Amplexus occurs always on land, never in water. Eight to ten eggs are laid and the male ejaculates the sperm directly over the eggs. The male will carry the nearly hatched tadpoles on his back to water. There tends to be considerable sibling aggression among the larvae. (Obst, 1988) Dozens of tadpoles may be placed in one large water hole by several males. Tadpoles reach transformation size in about ten weeks and feed on almost anything. (Walls, 1994)
> 
> ...


None of those references are considered authoritative... they are incorrect and horribly out dated... The incorrect information is because some people misinterpreted the wetting of the clutch after deposition with fertilization. It is actually the other way around. The sperm is deposited before the eggs... 

Please get your facts right before you decide to argue.... You can use the reference I posted earlier to get yourself started.... 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Irfin said:


> Here's some light reading from scholarly resources (maybe they'll move me from beginner back to general discussion):


I doubt it.... 



Irfin said:


> Refugial isolation and secondary contact in the dyeing poison frog Dendrobates tinctorius.
> 
> Refugial isolation and secondary contact in the dye... [Mol Ecol. 2006] - PubMed - NCBI
> 
> "Phylogenetic, nested clade, and dispersal-vicariance (DIVA) analyses of cytochrome b sequence data reveal the presence of two mitochondrial lineages that are associated with previously identified western and eastern uplands of this area. The geographical distribution of mitochondrial haplotypes and the results of DIVA and coalescent analyses suggest that there has been extensive secondary contact between these lineages indicating a complex history of connectivity between these western and eastern highlands, supporting the predictions of the DV hypothesis."


I see you didn't include the note that the last time there was any connectivity between those populations was 10,000 years ago... this has actually been discussed here multiple times.... 



Irfin said:


> I understand these papers and can read the language because I have a degree, background and job in science. I think they are an interesting start for future exploration.


And that and a dollar will get you a cup of coffee. I have a hard time believing those qualifications since you've badly misinterpreted the issue with subspeciation, fertilization and some other issues without realizing it or perhaps you did and hoped it would slip by..... 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Scott said:


> DFW doesn't need to be on this thread please. They have their own thread.
> 
> Let's not put them EVERYWHERE please.
> 
> s


There are others who take this sort of position to create a ruckus... one of whom was from Wisconsin and made all sorts of claims about all kinds of things... and claimed a science background.. 

Some comments 

Ed


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## frogfreak (Mar 4, 2009)

Ed said:


> There are others who take this sort of position to create a ruckus...


Yep,

And all I'm reading is blah, blah, blah (skim) blah, blah, blah (skim some more) blah, blah, blah...

See ya OP...Have fun with your lil science experiment


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## Ed (Sep 19, 2004)

Irfin said:


> What is the purpose of waiting after a female has laid her eggs in order to ensure they are fertilized before pulling them from the habitat? Does this not imply that there is a delay between egg laying and sperm delivery? And does this not then suggest that other males could contribute their sperm without amplexus?


It's because people mistook the male bringing water to the clutch with fertilization. It's the other way around.. fertilization occurs before the male returns. 



Irfin said:


> Aquatic eggs are fertilised by multiple males not engaged in amplexus in a stream-breeding frog


This really doesn't apply since Dendrobatids don't amplex during the actual oviposition event. 

Some comments 

Ed


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## aspidites73 (Oct 2, 2012)

According to this post by you, Irfin, you are a high school science teacher with a BS in Chemistry. Did you go back for your masters and PhD? Or, are you still a undergrad? 
http://www.dendroboard.com/forum/664835-post11.html


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## aurvrrat (Jul 23, 2011)

Hi,

I dont post on here much but I do read a lot. I have one thing to say and I will try not to ramble too much.

It is obvious how the majority of individuals, including myself, on this board feel about hybrids. Saying it was an 'accident' doesnt change a thing. The choice was made to keep two different 'types' of frogs together, knowing that there was even the slightest chance of interbreeding. That is no accident.

I personally dont mix ANY different frogs, to avoid that issue as well as aggression issues before they even start. 

If you want to sell your hybrids or even discuss them with less scrutiny, why not get with all the other hybrid breeders and start your own forum. call it MuttsRUs or something. 

I read this post earlier today and have read the others that have shown up since "he who shall not be named" started messing around with this forum, and I have to say it irritated me. But it wasnt until I came home and was misting and feeding my own frogs that it really got to me. I as well as many others i know strive to keep the lines of various frogs as pure as possibly, maybe that means breeding siblings for a generation but at least it isnt creating a mutt that could cause even larger problems in the future.

I hope that this is taken to heart at least by a few.

If you want to sell your hybrids, please do it elsewhere, I, personally would rather get out of the hobby than to deal with having to worry if the frogs I wish to add to my collection are hybrids and are being sold by someone who is less than honest.

I respect the OP's honesty, but I just wish there was another outlet for the ones who choose to make and breed hybrids, rather than saturating here.

I say this with no offense to anyone, but I wanted to say my peace.

Thanks,

Jess


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## Boondoggle (Dec 9, 2007)

aurvrrat said:


> I respect the OP's honesty, but I just wish there was another outlet for the ones who choose to make and breed hybrids, rather than saturating here.


I sincerely agree with the spirit of your post, Jess. I do, however, appreciate it being posted here, in that I can quietly and respectfully add Irfin's name to a list in my documents folder entitled "People to never, ever do business with".

Much appreciation for the thoughtful post from Dave, and Ed is on fire! Moral and scientific arguments very well stated all around. I may just refer to this thread every time this comes up again.


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## Irfin (Dec 15, 2009)

I really liked Ed's comments and appreciate his contribution.

I apologize to the community for causing trouble. I look forward to doing more research and contributing again once I've learned more.


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## Pubfiction (Feb 3, 2013)

TBH this shouldn't be in the beginner section.


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## jdooley195 (Oct 19, 2009)

Irfin said:


> http://www.dendroboard.com/forum/me...1849-cool-looking-azureus-morphing-out-2.html


You did see that the Azureus are normal looking now right?


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## 4oggz (Apr 20, 2014)

The adult form of the Hybrid turns out looking like this.....


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## Ed (Sep 19, 2004)

Irfin said:


> I really liked Ed's comments and appreciate his contribution.
> 
> I apologize to the community for causing trouble. I look forward to doing more research and contributing again once I've learned more.


If you had approached me differently, I would have been happy to point you towards a lot of that information. The a priori assumption on your part on a number of issues I have to admit didn't sit well with me. Much of this has been discussed on the forum in no part as part of debunking misinformation that had become entrenched in the hobby. 

I would have no objections to a properly established study to determine outbreeding depression or other genetic factors but there are a lot of things to keep in mind such as space for all of the frogs.. for example if you took the study out to six generations (to ensure that even out to 5 generations, there was little or no impact from outbreeding depression you would be talking about at a minimum of a study that would probably span more than a decade and would require sufficient space to ensure that there was sufficient representation from each generation (as you would have to track mortality across multiple forms (egg, tadpole, metamorph, juvenile, sub-adult, adult, and old adult)... Think about the outlay of time, space and money to conduct this study.... 

With respect to the idea of determining which factors are dominant and which are recessive, or codominant or even show incomplete dominance would require knowing which genes are that way in the original populations. Attempting to determine it starting with a cross is really not worth that much since the demonstration of dominance, recessive, codominance, and/or incomplete dominance may not work quite the same in the parental populations due to a number of genetic factors... see for example https://www.google.com/url?sa=t&rct...=Y0EvwxCyPXl3ycDyLVEQFQ&bvm=bv.67720277,d.cWc

So to come into the forum and make the claim that this is scientific research is a problem for those of us who consider ourselves scientists given the arguments that have been presented to date as justification to support the idea. 

So first off to have a proper experiment that would provide appropriate data you would need to first 
1) understand the behavior and biology of the species in question
2) have sufficient resources to undertake a study that can require more than a decade to even provide some data
3) have a plan in place to deal with all of the frogs that are surplus to the program. If you are working through an institution, then you would have to follow the IACUC guidelines for that institution. Generally this prohibits the passing of animals into situations where the animals will be used for commercial purposes
4) establish protocols that include controls. 


Some comments 

Ed


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## Ed (Sep 19, 2004)

jdooley195 said:


> You did see that the Azureus are normal looking now right?


The problem I had with it, was that nothing in the link showed an animal morphing out with a pattern I would have considered that abnormal. People often don't understand that even environmental factors can play a part in color and pattern development. For example incubating reptile eggs at high temperatures can result in aberrant coloration, aberrant scalation and in severe cases abnormal development including fusing of sections of the body or even organs being left outside of the body. 
To make a leap that it was an indication of a past hybridization event was premature to say the least.... 

Some comments 

Ed


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## Ed (Sep 19, 2004)

4oggz said:


> The adult form of the Hybrid turns out looking like this.....
> View attachment 116738


Last post used as an example, 

this is really pretty much not only uncalled for but shouldn't be really acceptable. If you can't make a reasonable argument against it, move on.... otherwise this stuff just takes up space to without adding any value. 

Some comments 

Ed


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## hypostatic (Apr 25, 2011)

Irfin said:


> I would like to learn more about tinctorius genetics. I intend to collect scholarly articles and present them at a later point.


This is not how one goes about doing science.

Speaking as a molecular biologist, this is also not a good way to learn much about tinctorius genetics.


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## jdooley195 (Oct 19, 2009)

Ed said:


> The problem I had with it, was that nothing in the link showed an animal morphing out with a pattern I would have considered that abnormal. People often don't understand that even environmental factors can play a part in color and pattern development. For example incubating reptile eggs at high temperatures can result in aberrant coloration, aberrant scalation and in severe cases abnormal development including fusing of sections of the body or even organs being left outside of the body.
> To make a leap that it was an indication of a past hybridization event was premature to say the least....
> 
> Some comments
> ...


Yeah, not sure where he was going with that. I'd even indicated using a color enhancing tad food.


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## Ed (Sep 19, 2004)

hypostatic said:


> This is not how one goes about doing science.
> .


Well maybe a review of all of the literature.. that would be an acceptable paper that could make it through the peer review system.. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

jdooley195 said:


> Yeah, not sure where he was going with that. I'd even indicated using a color enhancing tad food.


Except you can't enhance blue via diet. It is only produced by the reflection of blue light from the iridophores. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

aspidites73 said:


> According to this post by you, Irfin, you are a high school science teacher with a BS in Chemistry. Did you go back for your masters and PhD? Or, are you still a undergrad?
> http://www.dendroboard.com/forum/664835-post11.html


 If I understand you correctly the implication is that a person with a BA or BS in a science discipline is going to automatically produce an inferior experimental set-up. If that is the meaning, then I'm going to have to strongly disagree with it. All it requires is sufficient research into the data to ensure a proper understanding and setup of the protocols and experiment. It is true that in the ideal institutional setting these experiments are conducted by MS students under the auspices of a PhD, but history is replete with people who excelled with the lowly BA or BS degree. 

Some comments 

Ed


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## hypostatic (Apr 25, 2011)

Ed said:


> Well maybe a review of all of the literature.. that would be an acceptable paper that could make it through the peer review system..
> 
> Some comments
> 
> Ed


Literature reviews are essential in science, but with poor experimental design research doesn't progress far.

You don't need to get super fancy to do good science. But you do need to be extremely organized, observant, and analytical. Mendel didn't anything fancy, but he was EXTREMELY thorough and rigorous.

There ARE laboratories that look at dart frog (mostly pumilio I think) genetics. But the way their research is carried out is carefully planned and methodical. It's not just random breeding like the OP is doing.


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## jdooley195 (Oct 19, 2009)

Ed said:


> Except you can't enhance blue via diet. It is only produced by the reflection of blue light from the iridophores.
> 
> Some comments
> 
> Ed


Last side track question from me...

I meant the yellow morphing out. Would red enhancing food be bringing that out temporarily or is it just coincidence when a blue frog morphs more yellow or green than blue?


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## aspidites73 (Oct 2, 2012)

It is merely a statement of fact and a question. I agree history has seen people excel in the sciences without any degree. Gregor Mendel was un-educated as was Michael Faraday. My point is: Irfin has not shown the ability to understand basic concepts of research, as you pointed out. Instead of standing up for himself, he chose to allow you to do it for him, AEB his thanks to your post. The fact that people have achieved greatness without a degree is irrelevant. Irfin has already demonstrated he isn't yet one of them.



Ed said:


> If I understand you correctly the implication is that a person with a BA or BS in a science discipline is going to automatically produce an inferior experimental set-up. If that is the meaning, then I'm going to have to strongly disagree with it. All it requires is sufficient research into the data to ensure a proper understanding and setup of the protocols and experiment. It is true that in the ideal institutional setting these experiments are conducted by MS students under the auspices of a PhD, but history is replete with people who excelled with the lowly BA or BS degree.
> 
> Some comments
> 
> Ed


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## Scott (Feb 17, 2004)

You're right - it should be in the "Why are we talking about this again?" section.

If we had a section that indicated less knowledge than beginner, that's where it would be.

s


Pubfiction said:


> TBH this shouldn't be in the beginner section.


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## frogs are cool (May 22, 2010)

Scott said:


> You're right - it should be in the "Why are we talking about this again?" section.
> 
> If we had a section that indicated less knowledge than beginner, that's where it would be.
> 
> s


The best idea i have read this entire post!


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## ZookeeperDoug (Jun 5, 2011)

Scott said:


> You're right - it should be in the "Why are we talking about this again?" section.
> 
> If we had a section that indicated less knowledge than beginner, that's where it would be.
> 
> s


Just spat out my coffee. I don't care what some say, you're still occasionally funny Scott.


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## Dendro Dave (Aug 2, 2005)

Scott said:


> You're right - it should be in the "Why are we talking about this again?" section.
> 
> If we had a section that indicated less knowledge than beginner, that's where it would be.
> 
> s












*...STRIKES AGAIN!!!*

(Just kidding Scott, (Love ya buddy!) )

P.S. I just realized it's a pic of a HYBRID!!! 

P.S #2... (*Disclaimer* I'm pretty sure that isn't scott's actual face, would be a hell of a coincidence though )


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## Ed (Sep 19, 2004)

aspidites73 said:


> Instead of standing up for himself, he chose to allow you to do it for him, AEB his thanks to your post.


Point of clarification. I wasn't defending him, I was addressing the incorrectness of your implication. 




aspidites73 said:


> The fact that people have achieved greatness without a degree is irrelevant.


No, it's directly relevant to your comment and post. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

jdooley195 said:


> Last side track question from me...
> 
> I meant the yellow morphing out. Would red enhancing food be bringing that out temporarily or is it just coincidence when a blue frog morphs more yellow or green than blue?


Red no, yellow maybe. The development of the cells containing color are able to convert to one another to some extent (demonstrated by axolotls for example treated with allopurinol). It's possible that there was an initial formation of the wrong cells or that one of the other cells was slow in developing.... 

Some comments 

Ed


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## Frog Town (Oct 8, 2013)

This guy is shilling for DFW. I can read it in the way he is writing. He's trying to justify captive hybridization by discounting the naturally occurring morphs of D. tinctorius.


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## Ed (Sep 19, 2004)

Frog Town said:


> This guy is shilling for DFW. I can read it in the way he is writing. He's trying to justify captive hybridization by discounting the naturally occurring morphs of D. tinctorius.


What "naturally" occurring of tinctorius are you referring to??? Your statement has a lot more in common with some of the stuff on that site than a lot of his does... 

Some comments 

Ed


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## ted rowe (Mar 29, 2015)

azureus and inferlalinis are in the same species group the tinctorius group ...they can mate reguardless but why can tincts hybrid with arutus spieces that's a better question


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## Boondoggle (Dec 9, 2007)

ted rowe said:


> azureus and inferlalinis are in the same species group the tinctorius group ...they can mate reguardless but why can tincts hybrid with arutus spieces that's a better question


They can. That's a crummy question.


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## allegedhuman (Nov 19, 2014)

ted rowe said:


> azureus and inferlalinis are in the same species group the tinctorius group ...they can mate reguardless but why can tincts hybrid with arutus spieces that's a better question


I don’t want to inappropriately contribute to the necromancy of old threads but if can make a useful contribution…please don’t beat me for feeding necro-trolls…slowly whimpers and backs away…

Since there was a question regarding want more of a “biologically why” answer to the question why different species like tincts and auratus can hybridize I’ll offer one explanation based upon chromosome numbers. 

These two frogs are different species but both belong to the Dendrobates genus and are closely related to each other. Both species also have the same number of chromosomes in which diploid frogs in both species have 18 chromosomes with two copies of each chromosome (If “n” stands for chromosomes and diploid animals are described as “2n” then for these frogs 2n=18 pairs, 36 chromosomes in total). Because these species are closely related, many of the genes on the chromosomes are likely to be very similar or even nearly identical, positioned on the same chromosomes in both species and operate the same way. 

I am going to induce a flashback (or for younger members you can get an early start if you haven’t covered it yet) to biology classes covering sexual reproduction and a process called meiosis. Not sure how well this will go solely verbally so maybe googling a picture for meiosis would help? 

In both humans and frogs they are diploid animals which it means they have two copies of their genes, one copy from mom and one from dad. Since essentially half of your genes come from mom and half from dad, there needs to be a way to split and transmit one copy from each parent to the offspring and then match up the sets (kinda like pairing socks). 

In this case eggs and sperm are haploid  and only have one copy of the genes on each chromosome from a parent. If each parent gives one chromosome with copy of the genes on it to the zygote/pre-baby frog then there will be two copies of each gene after both parents donate. So mom’s eggs are haploid with just one copy of her chromosomes and she gives n=18, and dad’s sperm is also n=18, so in the end the baby frog gets two copies of each chromosome to end up with a pair of each chromosomes and to become diploid 2n=18 pairs for a total of 36 chromosomes. 

The two different chromosomes copies from mom and dad need to join up and pair with the matching copy from the other parent so the cells can replicate and divide to become a functional baby frog with a copy of gene from both parents off of the chromosome pairs. If both mom and dad are the same species then they should the same number of chromosomes and the genes from both sets very similar so they can match their equivalent copy from the other parent to pair properly. If this frog grows up and breeds it will also donate half of its chromosomes and would lay eggs that are n=18 to complement another similar frog that also produces sperm with n=18 where these 18 single chromosomes can pair correctly to make 18 paired sets. This means not only can two closely related species with the same number of chromosomes breed, but also that their offspring can be fertile and breed with other frogs with the same number of chromosomes too.

The problem is if the two different species have different numbers of chromosomes, like tincts are 2n=18 but oophaga species may be 2n=20. In this case, one parent would donate n=18 individual chromosomes and the other parent donate n=20 but the offspring now has 38 total chromosomes and would equal n=19. So if it manages to grow up (lots of other factors also are involved to determine if eggs are even viable to hatch but trying to keep it simple and just focus on why different chromosome numbers can cause infertile offspring) and tried to breed with either species of frog that was the same as their parent, this hybrid frog makes a different number of chromosomes than either parent. Parent 1 is 18, parent 2 is 20 and offspring is 19. When offspring’s 19 chromosomes try to pair up with either 18 or 20 from a potential mate there is an odd number of chromosomes and exact pairs are not made. If chromosomes are not paired when cells are dividing and separating they get lost, so the potential offspring is suddenly missing a whole chromosome and all the hundreds of genes on it that are probably really important and likely not able to breed.

That is why if two different closely related species have the same number of chromosomes, then it is possible they could breed and that their offspring would also be able to breed too. But it is also why breeding between species with different numbers of chromosomes makes it difficult to produce offspring and if offspring do survive and are born, they are often sterile (like mules).

Hope this kinda answers the “why” can closely related species sometimes breed and be fertile like a tinct and auratus. There definitely are many other factors that affect the ability to hybridize and breed with each other but this is maybe just a broad general tip for one reason why it biologically can occur between closely related species when live together in a small enclosure in captivity. In the wild, when they live in different regions and have space for different territories frogs can choose their own mates that behave properly for the kind of mate they expect based on if they look the same, call the same or act the same and belong to the same species. But stick just a few frogs in a glass cage and suddenly what is natural behavior changes and they no longer have much of a choice in who or what they breed with so you can see hybrids in captivity that normally you would not expect in the wild.

Sheesh, this ended up being really long-winded and technical but at this hour of night I can only hope what I wrote wasn’t too confusing and kinda made at least a bit of sense to some people? And I stress, this is only ONE factor and I am NOT saying mixing species with different chromosome numbers is a smart/safe idea because other factors also affect health of animals. There are many other factors that can impact if two different species can interbreed but at least I find thought this an interesting explanation about biologically how some interspecies hybrids like auratus x tinctorius can produce viable offspring.


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