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Heard the first calls from my group this morning. Sounds like at least one or two of them are officially "of age." We'll see what happens...
 

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I have two, one is about a year old and the other three years old. I have not heard any calling up to this point. Any tips for inducing it? Perhaps two females?
 

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It's only been a bit over a month but I was wondering if anyone has updates?
I'm going to be moving my three (2 are males for sure, I think the 3rd is also but haven't seen him call or heard three call at once) into an exo setup in the not too distant future and would really love to get them a woman. I'm wondering if the folks who were going to try temperature control on tads have had luck.
:)
 

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I have two, one is about a year old and the other three years old. I have not heard any calling up to this point. Any tips for inducing it? Perhaps two females?
Have you tried playing a recording of their call? Seems to work for me :)
 

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Ray - Are you going to try the temperature controlled tad raising? If so, would you mind going over your setup?
Would anyone be interested in joining a "citizen science" project to test the TSD (Temperature Sex Determination) hypothesis? It would require some standardization of tad rearing equipment, and perhaps a longer grow-out phase than normal. But it would be interesting.

cheers,

Afemoralis
 

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Would anyone be interested in joining a "citizen science" project to test the TSD (Temperature Sex Determination) hypothesis? It would require some standardization of tad rearing equipment, and perhaps a longer grow-out phase than normal. But it would be interesting.

cheers,

Afemoralis
Stefan Lötters, Dennis Rödder & Lisa Schulte are doing some research on the TSD hypothesis, since early 2011. Now that I think of it, I will contact Lisa and ask how this is progressing.
 

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No response from Lisa yet, but when I hear from her I will let you guys know.
 

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I got a response from Lisa Schulte. She was okay with me posting it on the board:

Hi Remco,
unfortuanately I have only bad news about the project. We could only breed very few frogs that survived the metamorphosis, most our tadpoles, that first looked very healthy never became little frogs. Anyways we had some fecal/urin samples of all tadpoles from different stages and we found Hormone-Test-Kits (ELISA) that are very very sensitiv to testosterone/estradiol. We tried them the first time short before christmas - but nothing: the kits could not identify any hormones, not for the tadpoles nor for the adult frogs (we knew the sex of). So this means that our project died with all the not quite metamorphing tadpoles. I wished I could have given you a more satisfying answer, especially because we put a lot of work in this, but I guess that is how science turns out many times...
Cheers, Lisa
 
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Ok here are some thoughts from an English Major, not a Bio Major.

Quote from this thread http://www.dendroboard.com/forum/general-discussion/6585-when-sex-dart-frog-determined-3.html

I remember Rthis being discussed before. When the azureiventris were brought in by Sean, I got some and bred them. I held back a group of 8 and exactly half became female. This test group was reared in the coolest area in my FR - on the floor, where temps in the 50's is very common. All morphed out with yellow markings. Another group of tads from the same clutch were reared in cups and kept a fairly constant 70 degrees and higher. All morphed out bright red/orange. The tads on the floor took twice as long to morph.
What if keeping the adults in the 50's is the key? Does the males sperm determines sex of offspring? If so, are we killing off "female" sperm with the high temperatures? What about not inside the body, maybe once the male deposits sperm on the eggs the "female" sperm die on their way to fertilize the eggs because of the temperature.

Did I explain that alright?
 

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Discussion Starter #73
Sex determination occurs during embryonic development so it doesn't matter how the tadpoles are reared.
 

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Discussion Starter #75
Some lit claims that only in temps that the species wouldn't normally be exposed to. Exposure to hormones has also been shown to affect gender in some species. The question here is whether the male majority of offspring is a result of husbandry errors or errors in tadpole rearing. I would wager that if fertilization and development occurred at cooler temps we would see a more equitable sex ratio in the offspring.
 

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I've read about hormone exposure affecting sex. Lotters et al. mentions larvae being found in water that was around 62F, could it be that the tadpoles never experience temperatures much higher than this?

Your hypothesis is interesting as well. Any ideas on what temps to keep them at?
 

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Discussion Starter #77
I will have to research more, but having exp. temps in their habitat, I can say that it gets really damn cold, at least in November. :)
 
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