# Paper of the Month: February 2016



## MasterOogway (Mar 22, 2011)

Sooooo I'm a little behind with posting papers. Holidays happened, and the wife and I are in the process of buying a house, things got a bit busy. But here it is! The long awaited for next paper of the month. 

Evidence of maternal provisioning of alkaloid-based chemical defenses in the strawberry poison frog Oophaga pumilio

Let me know if that works for everyone, or if you're having trouble accessing it. We can discuss it here, talk about questions, and try and decide who wants to post the next paper maybe? I don't mind doing it, but I'd love for someone else to jump in with some papers that they're excited about as well.

Anyways, some quick questions for this article that I was thinking about or that the article posted:


1) I thought Fig. 2 was interesting, there seems to be a large plasticity in the type of alkaloids showing up in tads, but not in adults. Could this be an adaptation for predation? e.g. Some tadpole predators might be more sensitive to certain types of alkaloids than others, and the tads that have sequestered those particular alkaloids will do better than others? Or it could just be an artifact of the sample size, or testing methods. 

2) Why do ovarian eggs but not fertilized eggs contain alkaloids? Is there a 'special' egg the female lays to be fertilized as opposed to feeding nutritive eggs? If so, what's the physiological mechanism behind that. 

3) As asked by the paper, does provisioning alkaloids to the tads diminish the females own alkaloid supply, and is this the reason behind females having a quantitatively higher amount of alkaloids than males. 

Food for thought, let's discuss!


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## Ed (Sep 19, 2004)

We do know that the availability of alkaloids is greatly variable over distance and time so variations in the provisioning of the eggs could also be due to simply what was recently consumed. They are inferring that there is a pathway from the maternal stores of the alkaloids in the skin to the eggs. While this is possible it is also possible that the alkaloids in the eggs could have been those recently in the diet as some alkaloids are lipophilic and may be deposited in the yolk with the mobilized lipids instead of ending sequestered in the skin. The low number of animals in the study don't provide any way to really exclude the other options. 

some comments 

Ed


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## Blocker Institute (Apr 19, 2010)

This is great!


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