Legless frog mystery solved
Posted by Sarah on June 27, 2009
It turns out that the deformed frogs and toads aren’t caused by chemical contaminants after all, or at least they aren’t all caused by them.
Scientists have discovered that some species of dragonfly nymphs eat the limb buds off of tadpoles, which results in frogs with missing or deformed legs, if the tadpoles survive to adulthood.
A parasitic flatworm, Riberoria trematode, which burrows into tadpole’s hindquarters, rearranges the limb bud cells while it’s in there, and that can result in extra limbs.
Although this has been going on for years, I don’t remember reading anything saying that natural predators might be responsible for the deformities, all I’ve heard is that it was due to chemicals, so I think it’s really interesting that it is something natural that’s causing the problems.
What do you think about this?
Mike said,
The study by Ballengee and Sessions puts forward an interesting potential explanation for some types of frog deformities. Unfortunately, their research fails to live up to the media hype; it does not solve the mystery of deformed frogs. In the laboratory, they found that some dragonfly larvae will remove limbs of tadpoles. However, Ballengee and Sessions did not actually test the predictions of the dragonfly hypothesis with rigorous data from the field. For example, a clear prediction of their hypothesis is that as the frequency of dragonfly larvae in wetlands increases, the frequency of missing-limb deformities in those wetlands is also expected to increase. Ballengee and Sessions did not test this prediction. Testing such predictions is a fundamental component of science. Until there are well-designed studies that examine the relationship between dragonfly density and frogs with missing limbs in nature, the relative importance of the role of predation in amphibian deformities will remain unknown.
.-= Mike´s last blog ..Peeper on a Penny =-.
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