TheFrog.org  
 · Forums · Reply · Statistics · Search · Post Count morphs

talk to the frog / General / a study on darts
Author Message
daystorm
Member
412 posts
412 posts

# Posted: 25 Jan 2007 16:38


OK lets try this again... This is an article that got placed in the canadart forum from a Qu


White's tree frog: 2:0:0
Budgie: 0:1:0
Parrotlet 2:0:0
Biewer yorkie 1:0:0
Crested gecko 2:1:0
Reed frog 1:1:0
daystorm
Member
412 posts
412 posts

# Posted: 25 Jan 2007 16:38


There is something seriously wrong with the posting thing...

I'lll try again later...


White's tree frog: 2:0:0
Budgie: 0:1:0
Parrotlet 2:0:0
Biewer yorkie 1:0:0
Crested gecko 2:1:0
Reed frog 1:1:0
daystorm
Member
412 posts
412 posts

# Posted: 25 Jan 2007 16:40


Notes on the compared toxicity of wild-caught and imported dendrobatids:
============================

DALY & MYERS (1967) have shown that there is no relation between the presence of a more or less vivid aposematic color pattern and the degree of toxicity of a more vividly colored species or individual in the Dendrobates genus. Sterodian(?) alkaloids C19H33NO2 and Cl9H33NO3 are among the ones found most often on the epidermis of Dendrobates species.

The nature and intra-dermic concentration of toxins in wild individuals also vary according to the type of preys consumed (DALY, 2000):

Toxins found in Dendrobatids feeding on Myrmecos ants:

-pumiliotoxins
2,5-disubstituted pyrrolidines *
2,6-disubstituted piperidines *
3,5-disubstituted pyrrolizidines *
3,5-disubstituted indolizidines *
4,6-disubstituted quinolizidines *
2,5-disubstituted decahydroquinolines *
3,5-disubstituted lehmizidines*
-histrionicotoxins
-gephyrotoxins

-Toxins found on Dendrobatids feeding on various rainforest coleoptera:

-trycyclic coccinellin
-batrachotoxin

-Toxins found on Dendrobatids feeding on Siphonotidae millipedes

-spiropyrrolizidin

There is a large variation in the number of toxins listed above found on wild specimens and species.

JONES (1998) has demonstrated the fact that dendrobatids captured in the wild and transfered right away to a nutritional diet containing none of the species listed above but only springtails, wingless fruit flies and pinhead crickets kept their toxicity in captivity for a period of 1 to 6 years.

Batrachotoxins are found exclusively on frogs of the genus Phyllobates.

But I tested an association of 2 or more other dendrobatid toxins on some laboratory mice, among which the following:

Pumiliotoxin,Epibatidin,Histrionicotoxin,Spiropyrr olizidin,Homobatrachotoxin.

Pumiliotoxin, found in the taxonomic complex D. pumilio is by far the less toxic of all substances; 50mg of dry extract were required to kill a mouse after a rather long period of muscular spams.

These 4 substances act by blocking the synapses' acetylcholinic and nicotinic receptors at various degrees. My experience was led on poison frog lots:

-for "wild" specimens: imported less than a month ago from their country of origin;
-for the captive-bred specimens: all issued from 2nd and 3rd captive generation presenting an association of at least 2 of the toxins listed above.

Here are the results:

On D. pumilio:

Dose >50 mg of dry extract from wild individual (n=18 ) to kill an adult mouse.

Dose >130 mg of dry extract from a CB individual (n=20) to kill an adult mouse.

On D. azureus, with presence of 1 to 6 toxins simultaneously on each subject, whether wild-caught or captive-bred:

Dose >= 2mg of dry extract from wild individual (n=27) to kill an adult mouse.

Dose > 8,5mg of dry extract from CB individual (n=20) to kill an adult mouse.

Average toxin dose (dry extract per individual) :1,6 mg.

On D. tinctorius:

Dose = 650


White's tree frog: 2:0:0
Budgie: 0:1:0
Parrotlet 2:0:0
Biewer yorkie 1:0:0
Crested gecko 2:1:0
Reed frog 1:1:0
daystorm
Member
412 posts
412 posts

# Posted: 25 Jan 2007 16:41


There we go, the font size was different so it wouldn't post. Anyways, I thought it was interesting so I posted it here. It was originally in french and got translated by someone on the canadart forum. Enjoy


White's tree frog: 2:0:0
Budgie: 0:1:0
Parrotlet 2:0:0
Biewer yorkie 1:0:0
Crested gecko 2:1:0
Reed frog 1:1:0
bwebb
Member
475 posts
475 posts

# Posted: 25 Jan 2007 23:12


They are actually somewhat less toxic than I would have expected. Wild caught D. azureus being the most toxic have a toxicity of ~100 mg/kg body weight which is only 27 mg/kg less than caffeine. The next most toxic, being CB D. azureus has a toxicity of 425 mg/kg (assuming the comma is supposed to be a decimal), which makes it almost 3.5 times less toxic than caffeine..in mice anyway.

Jennifer
Member
1522 posts
1522 posts

# Posted: 25 Jan 2007 23:58


That is such a weird standard.

Frog toxicity is measured by how it compares to the dose of caffeine required to kill a mouse?


FrogPrincess
bwebb
Member
475 posts
475 posts

# Posted: 26 Jan 2007 01:45


No, the study didn't compare that, I did.

Jennifer
Member
1522 posts
1522 posts

# Posted: 26 Jan 2007 01:59 · Edited by: Jennifer


Funny. In that case, it's cute.

Is the mechanisim by which it kills the same?

It seems a little odd inasmuch as we can drink caffeine and you think that you'd have to have a large dose to kill a person ...

And then, thinking about that, would a person or animal feel a toxic effect from a single frog?


FrogPrincess
bwebb
Member
475 posts
475 posts

# Posted: 26 Jan 2007 02:35


The doses they gave to the mice were concentrated and fairly large. I would think to reach a lethal dose the mouse would have to consume an entire frog and I think the taste of the frog would prevent that from happening. As for the mechanism, I believe it is similar as mice ODing on caffeine go into tetanic spasms before death. I think the mechanism is somewhat similar but caffeine antagonizes adenosine receptors, not acetylcholine. I guess I don't know much more about it off the top of my head.

Your answer

Bold Style  Italic Style  Underlined Style  Image Link  URL Link                    Disable BB codes *What's that?

 » Name  » Password 
 Only registered users can post here. Enter your login/password correctly before posting a message, or register first.
 

talk to the frog / General / a study on darts
 · Forums · Reply · Statistics · Search · Post Count morphs


Powered by miniBB forum software © 2001-2019