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Discussion Starter · #1 ·
well, my bastimentos have laid more eggs than they can deal with. at the moment there are two clutches of eggs, plus a few tadpoles are already deposited. So I was playing with the idea of taking out one of the clutches and experimenting with other food sources for the tadpoles. I know that eggfeeding tadpoles have very little success when not being reared by the parents, but was wondering what people have tried in the past and what seemed to work the best. I figure that it would be worth a shot since the parents will only be able to care for a few tadpoles at a time and it looks like they have their hands full.
 
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Discussion Starter · #4 ·
I have read about Robb's experiments, but unfortunately I don't have dart eggs handy (maybe I should get some auratus just for this purpose). Would people suggest that I try using chicken egg yolk? or maybe a mixture of egg yolk and spirulina/chlorella? or maybe something entirely different I haven't thought of?

and I'm not opposed to trying a few different things, so everyone should chime in with any thoughts on the subject.
 

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Whatever you decide to try, do it in extemely small doses. Spirulina and egg yolks will foul the water quickly. Maybe you could try live daphnia? Ideally, other pumilio eggs is what you would want to use. Then, other dart eggs that have been denucleated. Good luck. Its been tried many times before with little sucess.
 

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Do we really want to raise pumilio artificially? Isn't their parental care part of their allure? I understand kinetic not wanting the eggs go to waste. But I have heard people suggest that the parental care of pumilio is learned behavior and if raised artificially they will loose the will to raise tads. It is just a theory but you never know if it could be true. I say just let the eggs go to waste and let the parents take care of the tads, but on the other hand it would be an interesting experiment, to see if they morph, and later on if they live long enough to breed if they show signs of parental care. I hope you have good luck, as it may be helpful to establish other egg feeders in the hobby, lehmanii, histos, and grannies, even though they probally require different nutrients it would be a starting point.
 
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Discussion Starter · #7 ·
I have considered everything stated above. I do have to agree that the parental care of eggfeeders is part of the allure of them. and there is the danger that parental care is a learned trait. However, I still think that it would be a worthwhile experiment, especially since most eggfeeders are very scarce and extremely hard to breed in captivity. If a diet could be found to work effectively and consistently with eggfeeders it would help establish a stronger captive population of frogs like histrios and lehmanni. If in the end all I learn is that parental care is a learned trait, and hand-reared frogs are incapable of breeding (while getting this far would be HIGHLY unlikely) I think it would be worth it.
 

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It is definitely a worthwhile experiment, and if it doesn't work all you really lost were some tads that wouldn't have been raised anyway.
 

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I would think it is more of an instinct than a learned trait. If you raise tads of another frog, don't they still know how to jump, eat, hide, and breed without seeing other frogs do this? I think they would just do it on their own wether or not they were raised that way. Imitators can raise tads on their own, even though they may have been raised outside of the tank. Others would still carry tads to water, even if they weren't carried to water by parent frogs, but by the breeder. This is just my thoughts on this subject. Good luck with the experiment.
 

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I lean to it being instinct, but I have heard it being suggested it is learned. However just because jumping, and eating aren't learned traits doesn't rule out egg-feeding as a learned behavior.
 

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Congrats on getting them this far Rob.
 

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Nice. I highly doubt that frogs have as much learning capabilities as people do. I am sure they can recognize day/night cycles and stuff like that, but I am sure most animals could. I would stick with the instinct thing. Animals seem to know how to reproduce pretty well. Most animals (reptiles anyway), don't "raise" the young like children and teach them the fundamentals of life. I hope to hear more about your results Rob.
 

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Like everyone has pretty much said, there is no way that egg feeding is a learned behavior. The froglets don't tag around behind Mom after they morph to see how it's done. Clearly this is instinct. But that doesn't change the fact that artificially rearing tadpoles could lead to loss of the behavior of egg feeding. In fact, I would say it makes it even more likely. If it were learned, then there would be a chance of hand rearing the tadpoles and then having them still learn the behavior from adults. But it its instinct, which it is, then likely the behaviors are initiated by a few genetically programmed stimulus-response triggers. Hand rearing removes the selective pressure that makes sure only those frogs that possess the genetic triggers reproduce. This goes for all dart frogs, not just egg feeders.

That said, I don't think hand rearing is that bad, but ONLY hand rearing could be bad in the long run if we are concerned about maintaining natural behavior. At one time I really wanted to try to crack the artificial egg feeder diet. Now I'm torn. I think it would be very interesting from a scientific standpoint, challenging to be sure, and useful (as was already mentioned) for establishing difficult egg feeders in the hobby. I think it's worth doing but I also worry this would be opening a can of worms if the solution turned out to be easy to reproduce and it became common practice in the hobby. If I were to discover the magic egg feeder diet, I would be thrilled but I'm not sure how publicly I would broadcast my findings... but I would love to know the results of any successful experiments ;-) I guess you could say I both love and hate the idea of artificial diets for pumilio.
 

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Not trying to start an argument, as I have no experience in this area, but you agreed it was instinct, then you said it could be lost. If it is instinct, what would cause them to loose it. If they could lose it, then it would be a learned behavior. You can forget something you learned, but can you forget instinct? I believe it is instinct personally and that if raising them artificially became successful, I am not too certain down the road the new generations wouldn't eggfeed. Eggs removed from tanks for other frogs will still carry their tads, despite them not being carried.
Hand rearing removes the selective pressure that makes sure only those frogs that possess the genetic triggers reproduce.
Could you elaborate more on this? Are you saying that you have frogs, they lay eggs, but normally wouldn't have the genetic triggers to egg feed? So you then feed them artificially? What would have caused them to loose this gene, not how they are raised because genes would be setup before that? Also, say this did happen, then the lost gene could possibly come back, say if it skipped a generation, or came from only one parent.

I think this could be an interesting convo and possibly bring up some peoples ideas on this topic.
 

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mydumname said:
Not trying to start an argument, as I have no experience in this area, but you agreed it was instinct, then you said it could be lost. If it is instinct, what would cause them to loose it. If they could lose it, then it would be a learned behavior. You can forget something you learned, but can you forget instinct?
I agree, it's a good topic. Yes, you can forget something you learned but you can also relearn it. Instinct is genetically programmed. In nature, a frog needs all of the genes that program it to court, lay, and care for eggs plus genes to program it to carry tadpoles, and finally it needs to be program to feed tads. If any of the genes that control these behaviors are lost, then that frog has no chance of successfully reproducing and passing those lost genes to the next generation. Genes get lost all the time through various ways such as mutation and genetic drift but since animals that lose the genes we are talking about in nature don't reproduce, then the traits don't get passed on. If we hand rear eggs and tadpoles, we are taking over the role of those genes that program frogs to do these reproductive behaviors. If a frog loses any of those genes, it doesn't matter because we rear the eggs and tads and the missing or mutated genes get passed to the next generation. And it's actually worse than that. These behaviors take time and energy away from the parents that could be used to make more eggs. If we hand rear, then the frogs that produce the most eggs, maybe because they don't waste time with those other behaviors, are the ones that get the most genes passed to the next generation.

Just as natural selection weeds out the weak and unfit animals, removal of natural selection can allow otherwise unfit animals to not only thrive, but sometimes actually become the dominant type. Imagine many, many, generations of frogs reared by hand. There has never been any selection to make sure each generation gets the genes that program the instincts that make the frogs so interesting.

As far as genes skipping a generation and coming back. It gets really complicated. Too complicated to fully discuss here but in particular a thing called genetic drift causes genes that aren't under selective pressure to change in frequency and even dissapear from the population entirely just through random mathematical probability. There is much more to it but I would not want to bet on the outcome of genetic change in frogs in captivity for many generations. But I'm certain that changes will occur. And I'm also certain that changes will happen faster for those traits that no longer give the frogs a survival or reproductive advantage.

Wolves are a great poster child for these things so I'll use them here. Look at the behavioral differences between dogs and wolves. There are lots of things they still do the same but nobody would suggest that dogs and wolves behave exactly the same. Many of the behavioral traits in dogs came through selective breeding. That is artificial selection increasing the frequency of certain traits. But many other differences came about simply because the wolf behaviors were no longer useful to the dog so they faded away genetically over time. One quick example. Dominant wolf females lift their legs when they pee and subordinate males squat. In dogs very few females lift their legs and almost all males do. I don't think humans ever selectively bred males to lift and females to squat. It just happened through genetic drift over time because there was no longer a particular advantage for females to lift and there were no longer dire consequences (getting your arse kicked) for a subordinate male that does lift. Stuff happens.
 

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snip "Genes get lost all the time through various ways such as mutation and genetic drift but since animals that lose the genes we are talking about in nature don't reproduce, then the traits don't get passed on. If we hand rear eggs and tadpoles, we are taking over the role of those genes that program frogs to do these reproductive behaviors. If a frog loses any of those genes, it doesn't matter because we rear the eggs and tads and the missing or mutated "

Hey this sounds familar.
But to build on what Brent said (there is an excellant discussion of this in E.O. Wilson's Sociobiology by the way), with the artificial rearing of eggs and tads we may actually select away from frogs that rear their own offspring.

Ed
 

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I think the greatest risk to parental care behaviour will always be the environment we set them up in. This behaviour is likely controlled by multiple genes and would not be easily lost by random selection, let alone by direct selection. In Brent’s wolf analogy, dogs have lost some specific social dominance behaviours after thousands of years of intense selection and inbreedin. The maternal instinct to suckle young pups still persists. While theoretically it might be possible to lose this behaviour under intense selection pressure against it (only rearing clutches from frogs which do not show paternal care in an ideal setting), I don’t see this as a probable outcome from rearing random clutches.
 

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Will said:
While theoretically it might be possible to lose this behaviour under intense selection pressure against it (only rearing clutches from frogs which do not show paternal care in an ideal setting), I don’t see this as a probable outcome from rearing random clutches.
I agree with this completely. Rearing random clutches should not be a problem. The problem would be if hand rearing became the norm which could provide that selective pressure against parental care. I wonder what percentage of auratus clutches are hand reared vs. natural reared. Or what percentage of breeding groups are allowed to rear at least a few of their own. I actually suspect I may have a group of auratus that have lost egg caring behavior. They lay fertile eggs which can be successfully hand reared but I've never seen them carry a tad, or even get eggs to the hatching stage for that matter. Other species I have set up in similar vivs can pull off the whole show on their own. I'm planning to set them up in a viv specifically to provide optimal conditions for doing their own thing and see what happens.
 
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