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Frogbomination?

JamesM

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Mar 10, 2002
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From the BBC:
'Warning' over three-headed frog

Children in a nursery were shocked when they spotted a three-headed frog hopping in their garden.

The creature - which has six legs - has stunned a BBC wildlife expert who said it could be an early warning of environmental problems.
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I have some vague memory of reading somewhere (Fortean Times? This very forum?) about frogs clamping together very tightly during mating, leading people to believe they were viewing a single creature with a surfeit of limbs.

Herpetologists, aid me, I beg you.
 
JamesM said:
From the BBC:
I have some vague memory of reading somewhere (Fortean Times? This very forum?) about frogs clamping together very tightly during mating, leading people to believe they were viewing a single creature with a surfeit of limbs.
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I've heard tell of a beast with two backs; some folk claim to have seen one.

Herpetologists, aid me, I beg you.
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That line ain't gonna get you laid.
 
The article is 3 years old. And it turned out it was just 3 frogs doing it (like on the discovery channel).
 
Frogs with limb deformities, either missing, deformed or extra sets of limbs have been showing up in parts of the U.S. since the early 1990s, perhaps earlier but I don't recall any three headed frogs or even two headed frogs. On the other hand there are examples of two headed snakes and turtles that have been discovered. These develop embryonically inside the shelled eggs that incubate outside the mother's body.

The frog limb deformities have been attributed to a parasite attacking the developing limb bud in tadpoles causing them to split and develop extra limbs. The particular parasites, in turn, have been attributed to water pollution. If I recall Minnesota and Wisconsin are major sites for these deformities but they have shown up elsewhere as well. But there is controversy (of course) with other theories being advanced.

The frog limb deformity pictures are genuine. The multiheaded frog pictures look like fakes (I have seen some double exposures being passed off as tweo headed frogs) but the two headed turtle and snake pictures are real. I have seen the x-rays. There are cases of two frog eggs fusing and developing into siamese frogs but this is not the same as a two headed frog.

Many species of frogs do mate by males clamping onto females, look up "amplexus" for a description.
Not only will frogs/toads try and mate with two others at the same time, they will mate with rocks of the right size and clamp onto one's hand if given the opportunity and there is romance in the air.
 
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The parasites haven't been attributed to pollution, the deformities were. However, frogs in polluted waters have fewer parasites, and fewer deformities. Before the parasites were noticed, this puzzled environmentalists.
 
Silly Green Monkey said:
The parasites haven't been attributed to pollution, the deformities were. However, frogs in polluted waters have fewer parasites, and fewer deformities. Before the parasites were noticed, this puzzled environmentalists.
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I am sure it did and may still.

The way I see this research is that both parasites due to the agricultural runoff and pesticide pollution are responsible. The explosion of parasites causing limb defomrities could be directly related to excessive amounts of agricultural run-off/pollution (a polite way of saying cattle & other large animal feces) plus the presence of pesticides which compromise the immune system. But as I said above there are competing theories out there and the subject remains controversial in spite of the findings. Even Kiesecker titles his paper as a question.




Advance: In the current study, Kiesecker reports field and laboratory studies that conclusively demonstrate that trematode infection was required for the development of limb deformities in wood frogs. Deformities were more common at sites adjacent to agricultural runoff. The laboratory studies corroborate the association between pesticide exposure and increased infection with pesticide-mediated immunocompetency as the apparent mechanism.

Citation: Kiesecker JM. Synergism between trematode infection and pesticide exposure: A link to amphibian limb deformities in nature? PNAS, July 23, 2002, v. 99:15, 9900-9904.
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http://www.niehs.nih.gov/dert/profiles/hilites/2002/froglimb.htm


Deformed Frogs Form when Parasites and Pesticides Combine


EMBARGOED until 8 July 2002 at 5:00 p.m. -- Deformities in Pennsylvania wood frogs are linked to the combination of their infection by parasites and a weakening of their immune system caused by exposure to pesticides, according to a study by Penn State researchers to be published in the 9 July issue of the Proceedings of the National Academy of Sciences.

http://www.science.psu.edu/alert/Kiesecker7-2002.htm
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Well said steven grenard i was gonna say all that but didnt know where to start:) :) :) i did watch a programme about it a while ago seems frogs and other species do have natural mutations which have nothing to do with pollution
 
petra10 said:
Well said steven grenard i was gonna say all that but didnt know where to start:) :) :) i did watch a programme about it a while ago seems frogs and other species do have natural mutations which have nothing to do with pollution
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There is a good wrap-up at:

http://www.sciam.com/article.cfm?articleID=000D5DCC-CA4A-1E1C-8B3B809EC588EEDF&pageNumber=2&catID=2

that takes all the competing theories into account including the one you mention and the one I cited. In fact it says that different causes may all be involved in different situations. So the important thing is not to become dogmatic about one theory and discard the others.

This is definitely worth a read if you are interested in this subject.
 
thanks i had a quick look through.i was reading something in another thread you wrote about blood and i was gonna ask you for a good link but this one may help me i am gonna have a good read and see.thanks again
 
Jorghnassen said:
The article is 3 years old. And it turned out it was just 3 frogs doing it (like on the discovery channel).
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Oops. Sorry everyone. I really have to start double checking the dates on those articles. My remembrance of the whole mating thing was probably this very same story. For shame, JamesM, you have made a fool of yourself.

Still, I learnt the word 'amplexus'.
 
Alareth said:
"The day you stop learning is the day you die"
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Sadly, for some folk the day they stop learning occurs in their early teens, by which time they know everything. Especially how unfair it all is. :mad:

Today, I learnt what a jay looks like in the flesh and feather. I've never seen one before, city-boy that I am.
 
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