Sunday, April 22, 2012

Herps In the News- A Sweet Poison Frog?

Herpetologist Valeria Clark from Belfast’s Queen’s University was studying chemical secretions in a species of poison frog in Madagascar (Mantella). In this study they found that the frogs were able to secrete tauromantellic acid, which is a type of bile acid. This acid secretion is seen in both captive and wild species, and it is also the first molecule of endogenous origin, which means coming from within the organism, that has been documented in this animal group. More interestingly, the frog, which not only excretes poison and bile acid in its skin, also excretes sucrose. Interestingly enough, the frogs do not create this sucrose in captivity which suggests that much like the poisons they produce the sugars are also a side effect of their dietary intake. Valerie suggests that since the frog eats the ants that digest sugars from the sap of plants, that is how the Madagascar frog obtains its ability to produce sucrose. This Finding is the first finding of an animal secreting a sweet substance, with this information the only logical step is to ask if this behavior is adaptive. Normally, amphibians secrete substances that will taste bad to a predator and thus deters the predator from eating and attacking it but if a frog is secreting sugar then that would seem to give an opposite effect, one in which the predator is more inclined to attack. Also, another question we could ask is does it secrete different substances at different instances in time? For example, if there is a predator present it will secrete the poison it is so famous for but maybe when there is a female present then the frog can switch and excrete sucrose sugar so the female is attracted. Assuming this last statement turns out to be true we would then see males only excreting the sugar, but since I could only find the abstract of the paper and it said nothing about the experimental methods, we can only speculate. Continuing our speculation we could also see if more dominant males who excrete more sugar or high volumes of sugar which could attract female more than subordinate males. This would allow the females to assess the males’ ability to find found since the sugars can only come from their dietary needs. Again, as stated above this is only speculations derived from Valerie Clarks study, as shown through some questions we can now ask her study has opened up some great new research questions that are now available to be asked and answered.

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1 comment:

To Love What is Mortal said...

Interesting! It does seem counterintuitive. I wonder if its just an easy way to get rid of excess sugar and has no effect? Do the females not produce the sugar? Anyway, is a wild and wonderful world.