# Good species to try delayed nucleation on?



## trevorthetoad (Nov 5, 2012)

A while ago I read about Hans Spemann's experiment in which he used a human hair to split two halves of a newt egg perpendicular to the grey crescent, and basically forced identical twins out of the egg. I want to try this experiment myself on frogs. However, I have not been able to find enough information online about the eggs of different species to select one type of frog. Does anyone know of a species that lays very large eggs, spawns frequently, and isn't too hard to breed? Egg size and spawning frequency are very important factors.


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## Ed (Sep 19, 2004)

Xenopus laevis should fit all of your criteria. 


Ed


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## trevorthetoad (Nov 5, 2012)

Ed said:


> Xenopus laevis should fit all of your criteria.
> 
> 
> Ed


Thanks for the suggestion, but according to what I've been reading, clawed frogs are seasonal breeders. I'm looking for a species that spawns very often, like vents, but has much larger eggs.


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## Ed (Sep 19, 2004)

trevorthetoad said:


> Thanks for the suggestion, but according to what I've been reading, clawed frogs are seasonal breeders. I'm looking for a species that spawns very often, like vents, but has much larger eggs.


Under inside/lab conditions, you can cycle them and keep them ready to breed as long as you feed the females enough to keep them in condition. None of the dendrobatids produce eggs that are as large as Xenopus. If you have a sufficient budget and are working for an institution or business, you can always order Xenopus that are ready to lay (see for example Xenopus Express Products - Xenopus Suppliers) so you have eggs when you want them. 

Ed


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## trevorthetoad (Nov 5, 2012)

Thanks for all the info! I really appreciate it.


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## Ed (Sep 19, 2004)

Your welcome 

Ed


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## trevorthetoad (Nov 5, 2012)

I just did some research and found out that clawed frogs are illegal in California. Are there any other frogs that fit my criteria?


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## Ed (Sep 19, 2004)

trevorthetoad said:


> I just did some research and found out that clawed frogs are illegal in California. Are there any other frogs that fit my criteria?


The whole group of Pipidae is prohibited without a permit. If you are associated with an institution, you can apply to get the permit. Otherwise you will probaby have to be satisfied with hormonally cycled leopard frogs. 

Ed


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## trevorthetoad (Nov 5, 2012)

Leopard frogs are seasonal breeders, and according to what I've read can take a few months to be ready for breeding after spawning once. Im looking for a species that can spawn once every few days so that if I miss the spawning or the eggs die, I can try the experiment again after a few days instead of having to wait for a few months, or buying a new gravid female. Any other suggestions?


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## Blue_Pumilio (Feb 22, 2009)

Just go catch some in the canals in south Cali! Hahaha...j/k, though, they are fun to catch. 



Ed said:


> The whole group of Pipidae is prohibited without a permit. If you are associated with an institution, you can apply to get the permit. Otherwise you will probaby have to be satisfied with hormonally cycled leopard frogs.
> 
> Ed


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## Ed (Sep 19, 2004)

trevorthetoad said:


> Leopard frogs are seasonal breeders, and according to what I've read can take a few months to be ready for breeding after spawning once. Im looking for a species that can spawn once every few days so that if I miss the spawning or the eggs die, I can try the experiment again after a few days instead of having to wait for a few months, or buying a new gravid female. Any other suggestions?


Okay, I'm curious as to what your sources of information really are.... the reason I'm asking is because leopard frogs can easily be kept ready for reproduction through temperature and light manipulation (or even just by collecting them before they breed in the spring and refrigerating them). In addition, provided they have sufficient nutrient reserves, they can be prepped via hormone injection regardless of the time of year and have eggs as needed..... 

The problem your running into is that you need a large sized egg... this tends to mean you need a large adult frog and even then, the embryo size may still be small with the rest of the size being made up of yolk reserves. 

As for frequency of breeding, the larger the eggs, in general, the less frequent they tend to lay since it metabolically costs more per oviposition. 

You probably should look at some of the tropical direct developing Eleuthrodactylids (like Coqui's but you may regret having them in your house). 

Ed


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## trevorthetoad (Nov 5, 2012)

Injecting leopard frogs with hormones isn't really a practical option for me, and where I live there aren't wild frogs that I can collect. I might try Coquis (if I can find them for sale somewhere) because they're small enough for me to keep multiple individuals ready for breeding and lay really big eggs. Again, thanks for all the info!


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