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Discussion Starter #1
First let me apologize before hand if I don't use the terms correctly.

I'm not talking about hybrids, creating new morphs/patterns. I'm talking about assisted mate selection.

As a hobby, more times than not, we toss any pair into a tank and let them breed. A selection limited, forced situation. Is this the best approach?

When I have active breeding of a species, I'll hold back some amount of froglets and raise them to subadults in order to prepare for the next generation. From this group, I'll select a couple pairs or group that I feel best represent the species. Strong calls, good coloration/patterning, size, etc. Not trying to create something new here, or propagate some unusual trait.

Is this a bad approach? Does it not attempt to provide some amount of pre-selection, to an otherwise selectionless approach to breeding?
 

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That is a wonderful approach. Selective breeding is all important to herpetoculture, I have NEVER "tossed ANY pair together" of any species that I have bred. I am extremely selective in individuals that I purchase, usually with the particular intention of choosing future mates. From those pairings, I tend to hold back the best 1-5% I ever produce, and future selection and plans for pairing begins.

This is easier with certain species of animals than others, I certainly don't know if it's possible to acquire an eye for picking out the best froglets before they are old enough to start being sold, but with the snakes and geckos I keep it tends to be fairly easy to know which ones I like the looks of best.
 

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That is a wonderful approach. Selective breeding is all important to herpetoculture, I have NEVER "tossed ANY pair together" of any species that I have bred. I am extremely selective in individuals that I purchase, usually with the particular intention of choosing future mates. From those pairings, I tend to hold back the best 1-5% I ever produce, and future selection and plans for pairing begins.

This is easier with certain species of animals than others, I certainly don't know if it's possible to acquire an eye for picking out the best froglets before they are old enough to start being sold, but with the snakes and geckos I keep it tends to be fairly easy to know which ones I like the looks of best.
I'm afraid I disagree. This is line breeding for specific traits. We should be attempting to keep our gene pools as natural as possible, not increasing any one coloration or trait. Here is an example. If I take a Varadero with a high orange pattern and mate it with another I have deliberately chosen as another high orange pattern, I am now Selectively Breeding (often miscalled Line Breeding) for an orange pattern. Instead, I should be attempting to keep ALL the natural genes in the line. So what I should ideally do is to select a Varadero mate with a lot of Blue Lightning throughout his back to mate with my High Orange girl. In this we we are at least attempting to keep the genes as natural as possible and will perhaps keep the wide variety of patterns that Varadero are known for.
 

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Isn't beauty in the eye of the beholder?Isn't any and all breeding manipulation on our part(in the confines of OUR enclosures)?
 

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One thing to consider that is many of the offspring that we raise artificially face little (if any) selective pressure. Therefore, frogs that would normally succumb to predation due to high color/low color, size, speed, deformities, etc. are kept alive in captivity and bred back into the gene pool. There is also some evidence to suggest that the females of certain species select based on phenotypic preference (ie. some prefer more color, others less color, etc). While I understand the points above, by rearing frogs in captivity we somewhat negate any real attempt to "keep the lines pure" in a wild type sense. While my approach is usually to just toss frogs in together and see who makes it...who breeds...etc. I don't have a problem with Eric's approach.
 

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Actually what this is, is artificial selection toward a breed standard. Ideally, the mate choice should be to frogs that are as distantly related to that frog within a known population* (this is not hybrid or crossbreeding morphs) however for most of the populations the relatedness** of any frog to another frog of the same population is unknown. Often a person will obtain frogs of the same population from another hobbyist or breeder but this doesn't indicate relatedness as those breeders could have had the same parents or grandparents. If relatedness is unknown then the breeders should actually be chosen randomly. By choosing the breeders people are selecting frogs for a number of traits which due to the directed selection cause the loss of genetic diversity and eventually the accumulation of negative allelles.


*population is defined as group of the same morph or in the case of some of the visually attributed pumilio the same import

** excluding frogs tracked using TWI ASN program or Robb Melancon's Frog Trax.
 

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As regards the OP, it depends on ones goals. If, like mainbutter, your goal is to isolate particular genetics that result in specific extremes in order to produce an animal that is visually unusual/stunning, then line breeding is how it's done through most of herpetoculture.

If you, some of the other posters, are more interested in preserving as diverse a pool of the original genetic possibilities, then line breeding doesn't really serve that purpose.

It seems, unlike snake or gecko keepers, more PDF hobbyists fall in the latter group.

I would just like to point out the term "best frog" is not synonymous with the idea of a "visually appealing" frog. Line breeding eliminates alleles from the gene pool, and not just ones related to color/pattern. It makes me think of the production/mortality rates between heavily morphed boids and their common counterparts.
 

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Hope Eric does not think I'm jumping on him ,I too am guilty of selecting certain patterns in certain morphs that appeal to my own individual eye .For me it doesn't smack of right or wrong ,just bias, on my own part!
 

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If the aim is to keep the gene pool as static as possible, then mates must be random. While Ray is right in that there are a number of frogs in the hobby that likely would not make it in the wild, in a program to keep the gene pool static, this shouldn't matter because they should represent a portion of the population in the wild that also would not be fit to survive. If you do anything other than random pairings from distantly or unrelated pairs, then you're going to be having some sort of selection on the frogs.
 

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Discussion Starter #10
Perhaps the better way to think about it, is on the negative side. Where the choice is more about which ones NOT to include in the pool of candidate breeders.

I agree a certain amount of randomness is needed in the process. But after working with and observing many of these species for a few years now, I believe mate selection is a large part of their natural process. It's not just all about rolling the dice.

As hobbiests, without some well intended external selection, we're eliminating a large part of that natural, mate selection process, if not all of it. With limited populations in small enclosures, it's "If you can't be with the one you love, love the one you're with" for many species.

Within this hobby, the general structure of our seperate collections and populations, does not follow the natural processes occuring in the wild. IMO, we need to do more than simple random selection.
 

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Perhaps the better way to think about it, is on the negative side. Where the choice is more about which ones NOT to include in the pool of candidate breeders.

I agree a certain amount of randomness is needed in the process. But after working with and observing many of these species for a few years now, I believe mate selection is a large part of their natural process. It's not just all about rolling the dice.

As hobbiests, without some well intended external selection, we're eliminating a large part of that natural, mate selection process, if not all of it. With limited populations in small enclosures, it's "If you can't be with the one you love, love the one you're with" for many species.

Within this hobby, the general structure of our seperate collections and populations, does not follow the natural processes occuring in the wild. IMO, we need to do more than simple random selection.
There definitely is mate selection naturally, but the problem with that is that we don't know what the mate selection criteria is. And it is possible that it could change as a result of the environment. So a given female may choose a male in the wild that she may not choose when in captivity, for whatever reason. We don't know what is natural for these populations, so we don't want to try to mimic natural conditions in a mating environment.

Thus it's best to keep everything random.
 

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Discussion Starter #14
There definitely is mate selection naturally, but the problem with that is that we don't know what the mate selection criteria is. And it is possible that it could change as a result of the environment. So a given female may choose a male in the wild that she may not choose when in captivity, for whatever reason. We don't know what is natural for these populations, so we don't want to try to mimic natural conditions in a mating environment.

Thus it's best to keep everything random.
I respectfully disagree. Just because we can't mimick the natural mate selection process exactly, doesn't mean we should abandon reasonable attempts to try. Especially when the offered alternative, a random only process, whether adequate or not, isn't truely acheivable within our hobby.
 

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By choosing the breeders people are selecting frogs for a number of traits which due to the directed selection cause the loss of genetic diversity and eventually the accumulation of negative allelles.
To clarify---the frogs develop a greater likelihood of having a harmful mutation over time due to an increase in defective components of genes. By limiting the gene choices available through selecting for specific colors or external traits, you increase the chance that you will encourage a sickly line of frogs over time. It's like having less and less good parts from which to build an engine---after hit and miss from patching it together with poor parts, it's not going to last that long.
This might manifest in many ways we don't yet know, but a prominent example is the huge amount of health problems in purebred dogs who were not screened for genetic defects before being bred to one another, and passed on things like hip and knee dysplasia, blindness and extreme aggression (even in young puppies).

I really don't want that for these frogs. There's no way to undo that damage.
I tend to get a large group and let the frogs choose their own mates. Isn't that the way to do it?
 

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Perhaps the better way to think about it, is on the negative side. Where the choice is more about which ones NOT to include in the pool of candidate breeders.

I agree a certain amount of randomness is needed in the process. But after working with and observing many of these species for a few years now, I believe mate selection is a large part of their natural process. It's not just all about rolling the dice.

As hobbiests, without some well intended external selection, we're eliminating a large part of that natural, mate selection process, if not all of it. With limited populations in small enclosures, it's "If you can't be with the one you love, love the one you're with" for many species.

Within this hobby, the general structure of our seperate collections and populations, does not follow the natural processes occuring in the wild. IMO, we need to do more than simple random selection.
There is a good bit of data on how to manage populations in captivity and a lot of it is referenced in the ASN program (and a bunch has been cited here as well)

Ideally one would have a population with a diverse and known parentage (back to the original wild caught founders) and the population is managed through a taxon management plan where the genetic representation of each founder is managed and kept from being lost. With this sort of management genetic diversity and maximal longevity of the population in captivity can be sustained. With a founder population of 50 animals, greater than 90% of the genetic diversity can be sustained for more than 200 years with this method.

If the population is from a group of unknown founders (number and contribution to the population) and the frogs cannot be maintained as a colony (which allows for mate selection) then mate choice should be by random determination as this prevents bias whether conscious or unconscious.

The whole goal of enabling a population for sustainability is to manage it for maximal genetic variation, even providing mate choice doesn't mean that will occur as you don't know the contributions to the population from the founder and subsequent generations.
 

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It's a slippery slope.

Side 1 of the coin: What we may call "healthy or fit" in captivity may not be successful in the wild. I've noticed a lot of people think the healthiest frog is the biggest, fattest individual when in reality, that's not always a good way of determining the health. Look at our domestic livestock breeds that have been chosen for "the biggest fattest" individual and now, double breasted white tom turkeys cannot mate naturally now.

My dominant and breeder male pulchra and madagascariensis are the thinnest, most active, and smallest. In fact, my dominant male madagascariensis is very aggressive to the largest, fattest male in the tank and always wins in a dispute. However, there is no way for me to know if this is an adaption to captive life or what would perpetuate in wild populations, but I'm just using it for an example that "the biggest, fattest frog" isn't always reliable.

I have a pair of mantellas that the male has a short femur but his single offspring is normal.

Side 2 of the coin: Nutrition influences size and other factors, so its possible that a smaller frog may have had poor nutrition as a tadpole or froglet. In this case, it can somewhat be an indicator of health, but my question is, how does it influence the long term health of the frog?

Back before I learned about the "third wheel," I kept 2 male and 1 female cobalt together. The dominant male bullied the weaker male and it took me a long time to get him to recover. He's always been shier, more nervous, and eats much less than the other 2. But he calls more. Once I started to use a retinol supplement, he started to put weight on and activity and appetite levels increased.
 

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If the population is from a group of unknown founders (number and contribution to the population) and the frogs cannot be maintained as a colony (which allows for mate selection) then mate choice should be by random determination as this prevents bias whether conscious or unconscious.
Most of our locales are from small populations, correct? I'm curious if "inbreeding" is as serious as people cite since I would think that frogs from small locales would already have gone through a bottleneck phase and purge negative alleles from the gene pool.

Of course, you can fit thousands of frogs in a square mile and only a few megafauna in the same location...
 

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I respectfully disagree. Just because we can't mimick the natural mate selection process exactly, doesn't mean we should abandon reasonable attempts to try. Especially when the offered alternative, a random only process, whether adequate or not, isn't truely acheivable within our hobby.
Why wouldn't a random process be achievable within the hobby? In an ideal world, we would know parentage, but we don't. So it would seem to me that the best option is to get as random as possible. Random is random. Unless a particular breeder maintains separate, completely unrelated lines, get a male from one breeder and a female from another. It's not that difficult to be random.

If you try to mimic selection, eventually traits will be lost and the population in captivity won't truly reflect wild populations.
 

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Discussion Starter #20
...managed through a taxon management plan where the genetic representation of each founder is managed and kept from being lost...
Would not selecting offspring that closely matched the traits of the parents, work towards acheiving this?

If the population is from a group of unknown founders (number and contribution to the population) and the frogs cannot be maintained as a colony (which allows for mate selection) then mate choice should be by random determination as this prevents bias whether conscious or unconscious.
Mate selection is a successful, biased process. Doesn't removing that bias effectively water down the genetic pool and lessen those numbers of animals that more closely match the original founders? I agree we should maintain genetic variation beyond this, but wouldn't it be better to err on the side of maintaining the genetics of a proven success, rather than gambling on the roll of the dice? And further, doesn't the quote assume then that the husbandry and conditions we keep them in, are also unbiased, relative to their natural habitat? I don't feel that's the case, and keeper selection, again if done properly, could actually work to offset the bias that is occurring in our captive bred population.

The whole goal of enabling a population for sustainability is to manage it for maximal genetic variation, even providing mate choice doesn't mean that will occur as you don't know the contributions to the population from the founder and subsequent generations.
I understand this goal, but I'm not sure I agree it and a random implementation, best applies to our captive populations. And I'm no where near expert enough to offer a well thought out counter to it. I would think though, that selectively maintaining the traits of the line/original WC specimens, combined with periodically refreshing captive bred stock with new WC animals, would be a least one better approach.
 
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