Recent Komodo postings of Dr. Bryan Fry

[infernalis]

Bryan recently posted these to his facebook, worth sharing. enjoy.

UQ scientist Bryan Fry shows komodo dragon saliva not as toxic as believed | The Courier-Mail (http://www.couriermail.com.au/news/queensland/uq-scientist-bryan-fry-shows-komodo-dragon-saliva-not-as-toxic-as-believed/story-fnihsrf2-1226669638978)

Our study to see if there was any sort of proliferation of bacteria in komodo dragon mouths (which there would have to be if they were using it as a weapon) was pure science. Just curiousity about something put forth as gospel, but with a conspicuous lack of supporting evidence. But wow did we open a political shitstorm. We had people actively trying to block it. Zoos that were not just uncooperative, but were ringing other zoos to tell them not to participate in the study. Guess they were really attached to the fairy tale!! Luckily a couple zoos were actually interested in evidence based science and were super agreeable about participating in the study. The vets and staff at the LA Zoo, Honolulu and Houston were awesome.

https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-frc3/p480x480/969873_376609555798816_1941198861_n.jpg

[smy_749]

Makes you wonder how many other interesting discoveries are prevented from being made public / never given a chance to be researched.. ridiculous

[Chu'Wuti]

Where's the quote from, infernalis? I couldn't find it in the article you linked, and I wanted to send the whole thing to my local forum.

[infernalis]

I copied it from my facebook timeline.

Here Be Dragons: The Mythic Bite of the Komodo : Science Sushi (http://blogs.discovermagazine.com/science-sushi/2013/06/25/here-be-dragons-the-mythic-bite-of-the-komodo/#.UcrirthfvLN)

[formica]

I'm intrigued to read the findings, looks like the Journal is the only play i'll find them. The only films I've seen of Komodos doing what they do, did indeed see the animal take close to 3 days to die (David Attenbourgh program i think)

Is this the same Dr Fry that announced that all monitors carry venom which was also dismissed broadly?

[Gatorhunter1231]

I wouldn't say Dr. Frys findings were dismissed. There was a major conversation about it on kingsnake and which dr. fry even joined in on the discussion. There are enzymes and proteins in varanus salivia that are found in rattlesnake venom. Also the same enzymes he found in varanus were found in iguana and even corn snakes I believe. I believe it is used as a digestive aid and is incomplete to truely be called venom (my opinion).

It is a double edged sword which caused so much debate and why it was dismissed by so many. Findings are intriging but its a politcal world. What do you think will happen when a politicain that is not educated reads that monitors are venomous? We already have to fight with the government to keep the reptiles we enjoy. HR669 and other bans are real.

[formica]

I wouldn't say Dr. Frys findings were dismissed. There was a major conversation about it on kingsnake and which dr. fry even joined in on the discussion. There are enzymes and proteins in varanus salivia that are found in rattlesnake venom. Also the same enzymes he found in varanus were found in iguana and even corn snakes I believe. I believe it is used as a digestive aid and is incomplete to truely be called venom (my opinion).

It is a double edged sword which caused so much debate and why it was dismissed by so many. Findings are intriging but its a politcal world. What do you think will happen when a politicain that is not educated reads that monitors are venomous? We already have to fight with the government to keep the reptiles we enjoy. HR669 and other bans are real.

Ah I see - i think its fair to say they are not venomous any more than humans are in that case, unless they have a method of delivery other than a simple bite, like hollow fangs, humans also have digestive enzymes in their saliva, but we certainly cant be considered venomous, unless you happen to be a starch molecule, in which case you are screwed

here in the UK, venom has to be of a certain potency, before a dangerous animals licence is required, its not about the venom itself

I think if the US government is unable to process scientific information without freaking out, then it shouldnt be governing...but then you probably already know that lol

[Rob_H]

This paper only shows that bacteria communities in Komodo mouths depend on the environment.... but nobody ever suggested the bacteria spontaneously spawn from nothing in the Komodo's mouths by magic!

Where the bacteria come from is relatively unimportant: the bacteria have been found in the mouths of Komodo's in the natural scenario where these animals hunt. If these contain enough bacteria to kill large mammals through sepsis following a bite (still untested!) then nobody has been proved wrong.

I'm all for championing the venom and awesomely serrated teeth combo, but papers like these are not the best platform to continue the Auffenberg bashing!

[Gatorhunter1231]

"I think if the US government is unable to process scientific information without freaking out, then it shouldnt be governing...but then you probably already know that lol"

Thats hitting the nail on the head lol. They do have a sac sort of like the gila and beaded lizard in their bottom jaw where the enzymes/proteins are at. It comes through the saliva. Its is less complex then the gila and beaded lizards delievery which also chew their vemon into their prey. Im sure varanusmad or others are more up to date then I am. To bad Dave doesn't post much anymore, he knew all about it. All I know is I have been biten by baby savs, albigs, niles, crocs, and juvie crocs (teeth are to fear), savs, adult ackies, and tristis and Im still standing lol. Some have recorded swelling from bites which is worth noting.

[nepoez]

If a person bites me I'd get swelling.

[Zoo Nanny]

I wonder if any research has been conducted to determine if the bacteria found in the saliva of wild dragons is different than that found in captive. It would be interesting to know if there is possibly something in their environment that is causing the differences seen in the two studies. Mention was made of the stagnant water possibly contributing to the bacteria. Just as captive bred dart frogs do not produce the poisons in their glands because of change in diet/environment could the same thing be happening with the dragons?

[formica]

I wonder if any research has been conducted to determine if the bacteria found in the saliva of wild dragons is different than that found in captive. It would be interesting to know if there is possibly something in their environment that is causing the differences seen in the two studies. Mention was made of the stagnant water possibly contributing to the bacteria. Just as captive bred dart frogs do not produce the poisons in their glands because of change in diet/environment could the same thing be happening with the dragons?

this would be interesting - although i've always understood that Komodos gained their bacterial power from their enviroment (as it was previously understood)

The same is true for Flamingos, they wont turn pink without specific planktons to feed on

interesting on the dart frogs - do we know what they are missing from their diet? never knew that...

[Zoo Nanny]

There is a couple of different trains of thought on this. One is that the toxins are found in the insects eaten and the other that it is from plant material found on the insects. I don't believe any one has ever bothered to do any intensive research into the reason. Because of the lack of poison on the frogs and their intense colorations they have become popular in zoos.
Most of the animals eaten by the dragons are herbivores so I wonder if it is something that they are eating or is found on their skin.

[Rob_H]

This is exactly what the debate is about. Captive Komodos (the ones this study is based on) do not have nasty pathogenic bacteria in their saliva. Studies done on wild Komodos have shown that they do however. Bryan Fry et al argue that Komodos get the nasty bacteria from drinking water that buffalos and pigs (which are introduced) have been wallowing and defecating in. But they argue that this is unimportant, and the sepsis that results from a bite is actually due to injured animals that go and wallow in putrid water, allowing the deep lacerations caused by the dragon's bite to come into contact with the bacteria in the water.

Hence my comment: I'm not sure what this study is trying to prove, beyond showing that Komodo's kept in captivity don't have bacteria in their mouths. The dart frog example is an excellent analogue: just because something is environmentally dependent doesn't mean it's not important for an animal's survival or evolution. Neither the bacteria, venom, or water-hole arguments have yet been shown in a natural environment.

[Gatorhunter1231]

Agreeing with Rob H. I think this has an underlying tone to promote his venom research. I thought I was common sense that the buffalos laying in nasty water after being bite would cause infection. Venom, bacteria, infection, or whatever- that would be the least of my problems if a 8-9ft Komodo attached its mouth to my leg.

[infernalis]

Obviously more elaboration is warranted.

To put it all in perspective, see these two pictures of different water buffalo on Rinca island. The first showing just how feral the water is. That animal is on its way down. Just like it would be if I sliced its leg with a sterile scalpel and then let it flee into the festering water of a sewage treatment plant. It is injured and trying to hide in the only water around.... which is turbid black filth. The second image shows the sorts of injuries that they get. This one has part of its colon hanging out. Not lethal by itself but combined with that buffalo crap filled watering hole is a death sentence.

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc1/1001451_376624785797293_836738052_n.jpg

https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-prn1/1016626_376624692463969_1013924735_n.jpg

[Starbuck]

interesting on the dart frogs - do we know what they are missing from their diet? never knew that...

I'd always heard it was because they didnt have the toxins in their diet from a mainly ant based diet in the wild. They eat mostly small insects in the detritus of the forest floor/on large living-growth trees, from ispods to ants... but ive never researched it in depth.

[formica]

Obviously more elaboration is warranted.



https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc1/1001451_376624785797293_836738052_n.jpg

https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-prn1/1016626_376624692463969_1013924735_n.jpg

that second image is gross, thanks lol

I think the evidence is quite suggestive that Dr Fry's assumption is correct, i'm not sure it could be said to be conclusive tho - hopefully it will lead to more study, I have to admit I'm quite suprised that it hasnt been studied more in depth until now!

I'd always heard it was because they didnt have the toxins in their diet from a mainly ant based diet in the wild. They eat mostly small insects in the detritus of the forest floor/on large living-growth trees, from ispods to ants... but ive never researched it in depth.

I cant find much info on it at all, except that wild caught darts tend to loose their poison fairly quickly in captivity - intrigued to find out where the poison is coming from, could be direct, or it could be that their bodies are metabolising something else and turning it into poison - there are plenty of ants out there with neurotoxins, a fair few of them would give a frog a run for its money if it tried to eat them tho!

[Zoo Nanny]

Here are a couple of decent articles on the frogs.
http://www.lakeforest.edu/live/files/538-altoreviewpdf
ASA Newsletter - Dart Poison Frogs and Toxins (http://www.asanltr.com/ASANews-99/995frogs.htm)
I would love to see a comparative study on the diets and environments of wild vs. captive dragons. Captive dragons are eating a diet that has been raised in a controlled environment minimizing the bacteria and enzyme contents.

[murrindindi]

I'm intrigued to read the findings, looks like the Journal is the only play i'll find them. The only films I've seen of Komodos doing what they do, did indeed see the animal take close to 3 days to die (David Attenbourgh program i think)

Is this the same Dr Fry that announced that all monitors carry venom which was also dismissed broadly?



Hi, the articles are available to read on Bryan Grieg Fry`s website: venomdoc.com
The results have NOT been dismissed broadly as you suggest?

[formica]

Hi, the articles are available to read on Bryan Grieg Fry`s website: venomdoc.com
The results have NOT been dismissed broadly as you suggest?

thanks for the link, will check it out


...their venomous nature is disputed, there are other posts on this thread which sum up the reasons behind the dispute - dismissed was perhaps the wrong word

[MDT]

i didn't realize there were so many biochemists and toxinologists on this board....

[murrindindi]

i didn't realize there were so many biochemists and toxinologists on this board....

Yes, they`re "10 a penny" on these websites..... ;)

[murrindindi]

This is exactly what the debate is about. Captive Komodos (the ones this study is based on) do not have nasty pathogenic bacteria in their saliva. Studies done on wild Komodos have shown that they do however. Bryan Fry et al argue that Komodos get the nasty bacteria from drinking water that buffalos and pigs (which are introduced) have been wallowing and defecating in. But they argue that this is unimportant, and the sepsis that results from a bite is actually due to injured animals that go and wallow in putrid water, allowing the deep lacerations caused by the dragon's bite to come into contact with the bacteria in the water.

Hence my comment: I'm not sure what this study is trying to prove, beyond showing that Komodo's kept in captivity don't have bacteria in their mouths. The dart frog example is an excellent analogue: just because something is environmentally dependent doesn't mean it's not important for an animal's survival or evolution. Neither the bacteria, venom, or water-hole arguments have yet been shown in a natural environment.


Hi, I think you`ve clearly misunderstood what was stated in the articles; at no time have Bryan or his associates claimed the Komodo dragons drank the water the prey had been wallowing in and that`s where the bacteria in their mouths came from?
They found the most advanced venom delivery system of any reptile in V. komodensis.
Maybe you can read ALL the articles again and then offer your opinions? Alternatively, you could contact the scientists immediately and inform them you know better (just kidding)! ;)

[infernalis]

d3_eHNXRV8Q

[formica]

They found the most advanced venom delivery system of any reptile in V. komodensis.

in which artical is this discussed? or maybe you could just summerise and say what the venom delivery system is...it is not thru the saliva? I didnt see anything about it yet

[murrindindi]

in which artical is this discussed? or maybe you could just summerise and say what the venom delivery system is...it is not thru the saliva? I didnt see anything about it yet


Hi again, on the home page at venomdoc.com click on "Komodo dragon" in the list at the top.
It is venom, NOT saliva, though as far as having some bacteria in their mouths (all animals do), in this case that`s not what`s causing the tissue damage and ultimate death of their prey.
Edit: See Wayne`s post above!

[Gatorhunter1231]

A good read

A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2690028/#!po=23.5000)

Wish I could pull up the old kingsnake thread that Brian posted on. Him and FR had a nice discussion which is where I think Brian talked about the proteins and enzymes that varanus had in common with rattlesnake. A lot of things came up their that I haven't seen Brian post anywhere else. I know Dave (crocdoc) could probably link it or be more up-to-date. The study did not just stay on Komodo but relied on lace monitor (v.varius) and crocodile monitor (v. Salvadorii). Also worth noting that they are the closest relatives to meglania (Megalania prisca).

[infernalis]

Komodo dragon bacteria a myth (Science Alert) (http://www.sciencealert.com.au/news/20132606-24507.html)

Hot topic. ;)

[formica]

A good read

A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2690028/#!po=23.5000)

.

had a quick scan thru, much more detailed thanks! saved for later

[Rob_H]

i didn't realize there were so many biochemists and toxinologists on this board....
Yes, they`re "10 a penny" on these websites.....

I think using the public's money for research entitles them to discuss it though don't you think?

Either way, Fry et al has published in general journals (PNAS, Nature, Science), so of course they will welcome scrutiny by non-specialists.... and I would say that it's a huge achievement if you've explained your subject so well that non-specialists know enough to disagree with you.

Hi, I think you`ve clearly misunderstood what was stated in the articles; at no time have Bryan or his associates claimed the Komodo dragons drank the water the prey had been wallowing in and that`s where the bacteria in their mouths came from?
They found the most advanced venom delivery system of any reptile in V. komodensis.
Maybe you can read ALL the articles again and then offer your opinions? Alternatively, you could contact the scientists immediately and inform them you know better (just kidding)!

Ouch! I won't claim to have read all of Fry's work: I'd be seriously impressed if you have! However, this is exactly what Fry has said though; in talks at conferences, in press releases, and he's implied it in some papers.... including the one we're talking about. I really don't have time to dig the quotes out at the moment, but will if you remind me later/still want proof.

There are pros and cons to both the venom idea and the bacteria idea, but I don't think either one can be advocated as being more or less important in an ecological context until a study is actually DONE in an ecological context. This is the question where specific expertise in biochemistry is useless. I guess the main problem is that buffs and pigs are introduced, so we'll never really know the evolutionary context of the bacteria idea unless someone shows there are specific adaptations to allow their colonisation (such as a behavioural preferences for drinking putrid vs clean water etc). But again, whether predatory behaviour using pathogenic microbes is an evolved response or not doesn't detract that it may now be important for the animal's foraging ecology.

By the way, by no means do Komodos have 'the most advanced venom delivery system of any reptile'. I assume that was a typo... or that you've never seen a viper or elapid before ;).

[infernalis]

By the way, by no means do Komodos have 'the most advanced venom delivery system of any reptile'. I assume that was a typo... or that you've never seen a viper or elapid before ;).

I would certainly hope that the following statement was the INTENDED point....

"the most advanced venom delivery system in Varanidae species"

Do I assume correctly?

Komodo Dragons (http://www.venomdoc.com/venomdoc/Komodo_Dragon.html) - venomdoc.com

[Gatorhunter1231]

Not what was stated Wayne. It was stated most advanced in reptile. I already stated the most basic. Below that of the Gila, beaded, or rear fanged snakes.

[Zoo Nanny]

Komodo dragon bacteria a myth (Science Alert) (http://www.sciencealert.com.au/news/20132606-24507.html)

Hot topic. ;)
Wayne thank you for posting this link. Very interesting and answered my questions/curiosity. Description of the surgical removal of the venom gland and the tooth structure was very informative. I like his style of writing. Most scholarly articles can be difficult to follow for a lay person. Even though there are sections that were difficult to follow I was still able to understand the conclusions of the study.

[murrindindi]

Not what was stated Wayne. It was stated most advanced in reptile. I already stated the most basic. Below that of the Gila, beaded, or rear fanged snakes.

Hi, I think you need to contact Bryan Grieg Fry and ask his opinion on whether komodensis have the "most basic" venom delivery system "below that of Gilas and Beaded lizards and rear fanged snakes", I`m guessing he may have tested all of those, and you haven`t?
I can`t remember which article it was in, but I do believe "they" said the most advanced in any reptile yet studied (apologies if I`m mistaken)! :)

[infernalis]

Not what was stated Wayne. It was stated most advanced in reptile. I already stated the most basic. Below that of the Gila, beaded, or rear fanged snakes.

hence the wording of my post... context is everything.

[formica]

the artical and publication that I read, by Dr Fry, said ''most complex'', not most advanced - either way, i'm not sure how a gland which secretes venom between the teeth, essentially in the same way that a saliva gland secretes saliva, is more advanced or complex, than a pair of hinged, hollow fangs or a cobras jet stream, tbh

[smy_749]

the artical and publication that I read, by Dr Fry, said ''most complex'', not most advanced - either way, i'm not sure how a gland which secretes venom between the teeth, essentially in the same way that a saliva gland secretes saliva, is more advanced or complex, than a pair of hinged, hollow fangs or a cobras jet stream, tbh

Maybe you just don't understand to the same level as Dr. Fry (world renowned scientist in his field)...its a possibility.

[murrindindi]

the artical and publication that I read, by Dr Fry, said ''most complex'', not most advanced - either way, i'm not sure how a gland which secretes venom between the teeth, essentially in the same way that a saliva gland secretes saliva, is more advanced or complex, than a pair of hinged, hollow fangs or a cobras jet stream, tbh


Hi, I think you may be right, they stated the most complex, then again, define "most complex" as opposed to "most advanced", I guess we can take them in different ways!
I cannot see how an animal (V. komodensis in this case) that can deliver venom with one very quick slashing bite can be described as "more basic" than the Gila and Beaded lizards, both of which must hang on to the prey for significantly longer in order the venom seeps in? I would say the dragon has the more efficient (advanced?) delivery system.
They aren`t suggesting the gland itself is more complex so much as the delivery of the venom (along with their tooth structure) that makes it so sophisticated/complex/advanced (at least that`s how I take it)?

[formica]

indeed, advanced does not mean complex, advanced indicates some improvement in the efficiency of the venom delivery

I'm not sure that the Komodos method is more effeciant, than injecting direct into the blood stream tbh, the komodo is pretty much relying on an unknown amount being smeared over the skin and inner tissues, the body of the animal will quickly react and cause swelling which will slow down the amount of venom that can enter the body, injection doesnt give the body this oppertuntiy, the venom will spread thru the body within seconds, depending on the heart rate of the animal - and the fact that animals do not die within minutes of being bitten by a Komodo, indiciates that their Venom is not effeciant, or even massivly useful


smy_ - stop with the snide little comments and join in the discussion, its getting old. i'm not claiming to be world renowned scientist, but I have intelligence which I like to use to discuss ideas, and no world renowed scientist is going to look down on me for that - in the way that you are doing

[infernalis]

I know for a fact Bryan has read this, and is likely to check in on it from time to time, is this really the way you would behave if you were attending one of his presentations?

It's perfectly fine to ask questions, it's perfectly fine to refute what you have read, but calling names in class is childish. (hint hint) ;)

[smy_749]

Its not a snide remark. You are doubting his research, saying you don't see how it could be advanced or complex either way. And I'm just saying, you don't understand as much as Dr. Fry does so if he says its advanced or complex, than it probably is.

[MDT]

indeed, advanced does not mean complex, advanced indicates some improvement in the efficiency of the venom delivery

I'm not sure that the Komodos method is more effeciant, than injecting direct into the blood stream tbh, the komodo is pretty much relying on an unknown amount being smeared over the skin and inner tissues, the body of the animal will quickly react and cause swelling which will slow down the amount of venom that can enter the body, injection doesnt give the body this oppertuntiy, the venom will spread thru the body within seconds, depending on the heart rate of the animal - and the fact that animals do not die within minutes of being bitten by a Komodo, indiciates that their Venom is not effeciant, or even massivly useful

Tell me what kind of peptides, enzymes, kinins, etc are present in the Komodo's venom? How do you know how efficient their venom is? Are you basing your guesses on experience with what? Why does the animal *have* to die within minutes to be considered "massively useful"? The fact that Komodo's are the apex predator in their environment tells me that their venom is quite efficient.

Not trying to be a douche, but until those little tid bits are understood, it's strictly conjecture....

[formica]

Its not a snide remark. You are doubting his research, saying you don't see how it could be advanced or complex either way. And I'm just saying, you don't understand as much as Dr. Fry does so if he says its advanced or complex, than it probably is.

I dont doubt the research, I am questioning the conclusions, there is a difference

Tell me what kind of peptides, enzymes, kinins, etc are present in the Komodo's venom? How do you know how efficient their venom is? Are you basing your guesses on experience with what? Why does the animal *have* to die within minutes to be considered "massively useful"? The fact that Komodo's are the apex predator in their environment tells me that their venom is quite efficient.

Not trying to be a douche, but until those little tid bits are understood, it's strictly conjecture....

If an animal takes days to die, as appears to be the case with Komodo prey, there is a significant risk that the animal will escape, or at least get far enough away for the lizard to miss out on a meal, or worse fight back and injure the Komodo, regardless of how deadly the venom may be over a longer period, these risks are not insignificant - this isnt the case with for eg a rattlesnake, when it strikes, its prey dies very quickly, this reduces the oppertunity for the prey to fight back or escape

that is what I mean by more efficient - you dont have to be a biochemist to ask these questions

[murrindindi]

indeed, advanced does not mean complex, advanced indicates some improvement in the efficiency of the venom delivery

I'm not sure that the Komodos method is more effeciant, than injecting direct into the blood stream tbh, the komodo is pretty much relying on an unknown amount being smeared over the skin and inner tissues, the body of the animal will quickly react and cause swelling which will slow down the amount of venom that can enter the body, injection doesnt give the body this oppertuntiy, the venom will spread thru the body within seconds, depending on the heart rate of the animal - and the fact that animals do not die within minutes of being bitten by a Komodo, indiciates that their Venom is not effeciant, or even massivly useful.


I think you`ve missed something; the fact the largest prey may not die within minutes (adult buffalo, horse, etc), doesn`t mean the venom isn`t efficient or important, it certainly IS, as BGF states, "it`s another weapon in their arsenal".
Just because they may need to wait a few days/even weeks for a large prey animal to become immobile/die is of little importance when we consider the amount of energy it will supply!
It could be expected that the venom would have a greater (faster) effect on smaller prey.
EDIT: The fact the prey may move some distance before dying is clearly not a problem for an animal that can detect a carcass from up to 11km away!

[smy_749]

This is just a thought. But why does complexity / advanced level of something have to be associated with efficiency? Could it not just refer to the amount of evolutionary changes which were required to reach that end result? Could it not just be the way that the venom/bacteria/toxin works, not how quickly it kills?

I'm sure he knew what he was saying when he said it, I think we just don't understand what he meant by it.

[formica]

I think you`ve missed something; the fact the largest prey may not die within minutes (adult buffalo, horse, etc), doesn`t mean the venom isn`t efficient or important, it certainly IS, as BGF states, "it`s another weapon in their arsenal".
Just because they may need to wait a few days/even weeks for a large prey animal to become immobile/die is of little importance when we consider the amount of energy it will supply!
It could be expected that the venom would have a greater (faster) effect on smaller prey.

I'm not saying it isnt important - just disputing the claim that it is more effeciant than other reptiles, killing prey quickly is a vital aspect of the behaviour of a predator, for the reasons i said above - obviously the Komodo has found a way around this, because it happily sits and waits for its prey to die for days at a time

[smy_749]

the artical and publication that I read, by Dr Fry, said ''most complex'', not most advanced - either way, i'm not sure how a gland which secretes venom between the teeth, essentially in the same way that a saliva gland secretes saliva, is more advanced or complex, than a pair of hinged, hollow fangs or a cobras jet stream, tbh

I'm referring to this. Not whether it is more efficient, as I stated more advanced or complex, doesn't have to be more efficient necessarily. I don't think there is any argument over weather a death adder or Komodo dragon venom is more lethal.

[murrindindi]

Its not a snide remark. You are doubting his research, saying you don't see how it could be advanced or complex either way. And I'm just saying, you don't understand as much as Dr. Fry does so if he says its advanced or complex, than it probably is.


I didn`t see your reply as disrespectful at all.
Too many "armchair experts" offer opinions ("know" things), that are not based on knowledge or experience and in so doing confuse the issues even more.
That remark is not directed at anyone in particular, I`m generalising, and it`s the truth! :)
I`ve had a number of discussions with Bryan, he`s convinced me that the research he and others have completed is valid in regards to Varanids and venom (and it`s usefulness).

[formica]

This is just a thought. But why does complexity / advanced level of something have to be associated with efficiency? Could it not just refer to the amount of evolutionary changes which were required to reach that end result? Could it not just be the way that the venom/bacteria/toxin works, not how quickly it kills?

I'm sure he knew what he was saying when he said it, I think we just don't understand what he meant by it.

yes for sure - evolution doesnt have much concern for efficiency in the way we understand, whatever works best will become part of a species make up

Its not Dr Fry that said it was more advanced or efficiant, it was only posts on this thread which said that - Dr Fry used the word Complex - which I think is an important distinction to make

[murrindindi]

l - and the fact that animals do not die within minutes of being bitten by a Komodo, indiciates that their Venom is not effeciant, or even massivly useful




Yes, you did clearly state it wasn`t efficient and not "massively useful" (important)! :)

[formica]

l - and the fact that animals do not die within minutes of being bitten by a Komodo, indiciates that their Venom is not effeciant, or even massivly useful




Yes, you did clearly state it wasn`t efficient and not "massively useful" (important)! :)

I stand by my assertion that its not effeciant, and because of the time scales involved I dont see how it can be massivly useful - whether its important or not, I dont know, do we even know what the venom is doing?

Do we know for sure, that the animals which are coming to the pools, are not already dying? its just very strange, for an animal to accept being bitten by a predetor, and then just sits there to die for days on end - do we know how many animals that are bitten, then die and are eaten by the Komodo? or the number of animals which attempt to flee or fight back, if they dont, then why not? could this be a special property of the venom or is something else going on? there are too many unanswered questions for this riddle to be solved yet imo

[MDT]

I dont doubt the research, I am questioning the conclusions, there is a difference
- you dont have to be a biochemist to ask these questions

So Dr Fry's conclusions are in error? Good to know.

[murrindindi]

yes for sure - evolution doesnt have much concern for efficiency in the way we understand, whatever works best will become part of a species make up




Surely if something "works best" it`s more efficient (it benefits the animal)? That`s how evolution works and animals either survive or disappear, they become more efficient in whatever way!

[murrindindi]

So Dr Fry's conclusions are in error? Good to know.


Shhhhh, we don`t want Bryan to know there are people who disagree with his findings.....:wacky:

[formica]

Surely if something "works best" it`s more efficient (it benefits the animal)? That`s how evolution works and animals either survive or disappear, they become more efficient in whatever way!

its relative isnt it, just because it works best for the Komodo, doesnt make it more (edit: advanced) than all other reptiles, which is what was stated earlier in the thread

[murrindindi]

[QUOTE=formica;850167][QUOTE=murrindindi;850164][QUOTE=formica;850114]l - and the fact that animals do not die within minutes of being bitten by a Komodo, indiciates that their Venom is not effeciant, or even massivly useful


I stand by my assertion that its not effeciant, and because of the time scales involved I dont see how it can be massivly useful - whether its important or not, I dont know, do we even know what the venom is doing?

Yes, we do know what effect the venom has, it`s all clearly stated in the articles BGF and co. have completed. For one thing it contains an anticoagulant, to suggest that would not have a detrimental effect on a prey animal is rather naïve (massive bleeding, shock). You and any other "doubters" really need to contact Bryan, I`m almost sure he would be happy to offer more details (or admit they were wrong and you are right). :D

[Zoo Nanny]

The larger prey that are able to get away are also introduced species to the area. The argument regarding the buffalo and waiting for their death shouldn't be a factor. Normal prey for the dragons would be smaller. According to the paper the venom would "induce immobilizing hypotension." and also states "Such a fall in blood pressure would be debilitating in conjunction with blood loss and would render the envenomed prey unable to escape."
A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2690028/#!po=23.5000)

[murrindindi]

The larger prey that are able to get away are also introduced species to the area. The argument regarding the buffalo and waiting for their death shouldn't be a factor. Normal prey for the dragons would be smaller. According to the paper the venom would "induce immobilizing hypotension." and also states "Such a fall in blood pressure would be debilitating in conjunction with blood loss and would render the envenomed prey unable to escape."



Thanks for that link, though I`m sure the "doubters" will find something/many things/everything?) to dismiss! :)

[formica]

The larger prey that are able to get away are also introduced species to the area.

thats the kind of info I'm after, thanks, still havnt finished reading that publication

[Zoo Nanny]

Thanks for that link, though I`m sure the "doubters" will find something/many things/everything?) to dismiss! :)
I can't take credit GatorHunter1231 originally posted it.

[murrindindi]

its relative isnt it, just because it works best for the Komodo, doesnt make it more (edit: advanced) than all other reptiles, which is what was stated earlier in the thread


No, that was my mistake is using the word "advanced" rather than complex, it doesn't take away from the fact they clearly are more adept at killing their prey because they have a very efficient venom and venom delivery system. If it weren`t efficient (of benefit) they surely would have lost that ability by now?
You are commenting on animals that you are not yet that familiar with at this point in time. I truly hope your interest with Varanids will continue and before long you`ll have deeper understanding (I`m not being patronising).
I must say it`s nice to have a civil discussion, thanks for your input (and everyone else`s), whether we agree entirely or not!

[murrindindi]

I can't take credit GatorHunter1231 originally posted it.

Take the credit, it won`t come around too often.... :D

[Zoo Nanny]

murrindindi I have to agree with you this discussion has been really good. I've always found documentaries on Komodo's to be fascinating. I've learned a great deal more today from this discussion and posted links than from any documentary I've seen. So thank you folks for peaking my curiosity even more and supplying the information to learn from.

[infernalis]

Shhhhh, we don`t want Bryan to know there are people who disagree with his findings.....:wacky:

I like his response to the naysayers, but I would break forum rules posting it. :D

[infernalis]

The Myth of the Komodo Dragon?s Dirty Mouth – Phenomena: Not Exactly Rocket Science (http://phenomena.nationalgeographic.com/2013/06/27/the-myth-of-the-komodo-dragons-dirty-mouth/)

[venomdoc]

Some sensible questions here. First, I would like to stress that at every opportunity we have gone to great pains to stress that anguimorph lizards are of but of trivial direct medical importance to humans (with the exception of helodermatids and of course the komodo dragon).

The anguimorphs have a combined arsenal system employing teeth and venom. Helodermatids are one extreme, with the deeply grooved gracile teeth restricted to a venom delivering role. In contrast, komodos have the large serrated teeth as the primary weapon, using a grip-and-rip strategy to inflict deep parallel wounds. Mechanical damage that in some cases results in very rapid death from blood loss (eg slicing the femoral artery). The role of the venom is to exaggerate the blood loss and shock inducing mechanical damage caused by the bite. We have identified two main actions common to all anguimorph venoms: anticoagulation and hypotension. Enough loss of blood would lead to a drop in blood pressure sufficient to induce shock or unconsciousness. So anticoagulant toxins facilitate a steady march in this direction. Similarly,hypotensive toxins accelerate the unconscious endpoint.

Komodos evolved not in Indonesia but in Australia, and were not the biggest to have roamed, at least two larger varanids existed to predate on megafauna. The second largest radiated to Timor while komodo radiated to Flores and nearby islands. The modern day situation is that the komodos have three mammalian potential prey choices. All of which are feral. The introduced pigs and deer are within the natural prey size (40-50 kg) while the buffalo are dramatically larger than would have been a reasonable size for komodos to kill and also occupy an ecology unlike anything in Australia.

These collective differences are starkly reflected in attack success. Attacks on pigs and deer are extremely successful. About three quarters bleed out within the first thirty minutes and another approximately fifteen percent succumb within three or four hours. Repeated attacks by the same or other komodos is not uncommon. In dramatic contrast is the outcome of attacks on water buffalo. Which invariably get away, with deep wounds to the legs. Upon which they go and stand in feces filled watering holes. Creating a perfect scenario for dramatic infections. Not from the dragons mouth, but rather having an environmental source. Deep wounds in feces laden water is a perfect scenario for the flourishing of bacteria, particularly the nasty anaerobic types. Thus, the sampling of komodo mouths that purported to show them harbouring pathogenic bacteria neglected to sample the real source of any infection to the water buffalo: the faeces filled waiting hole the dragons recently drank from. It has been a man made artificial scenario all along that has nothing to do with the evolution of the predatory ecology of komodos.

Having gotten septicaemia in Flores from deep lacerations resulting from a boating mishap in Flores harbour (water that is pretty disgusting) I can attest to how quickly such environmental sources can produce life threatening infections. As a consequence of the Flores doctor doing a shockingly inept job of cleaning up the wounds before stitching them up, I ended up delerious and near unconscious in the Bali International SOS clinic 36 hours getting emergency IV antibiotics.

There is nothing special about komodos. They are simply the largest extant species of a clade that had two extinct larger species and has two extant species (V. varius and V. salvadorii), all of which share the unique large,blade like serrated teeth. None of which have ever had the slightest whiff of using bacteria as a weapon.

As for the relative complexity of the varanid venoms glands, this was from our 2009 paper when we discovered it had six discrete compartments. More than any other reptile. However, when in 2010 we looked at a variety of anguimorpha lizards, varanid and non-varanid, we discovered that the ancestral condition was to have one gland per tooth, so 15 or more small glands for anguiids for example, with these glands fusing into larger structures independently in lanthanotids/varanids and also in the helodermatids. So the lanthanotid/varanid gland structure comprised of a encapsulated gland with fused compartments (6 total including one massive one as per the images on my webpage www.venomdoc.com) is equally derived to the helodermatid. However, the most advanced venom delivery architecture in the reptiles is of course the three independent lineages of front fanged snakes (Atractaspis, plus elapids and vipers), with the vipers the most intricate due to the hinged fangs.

Cheers
Bryan

[infernalis]

Thank you for taking the time to post Bryan.

[formica]

fascinating read, yes thanks for taking to the time to post and answer the questions, much appreciated!

I am surprised that anticoagulant and hypertensive toxins are not of great value to medical science, considering the accelerating rise of heart disease and other related conditions - is there anything that makes the Komodos particular toxins unsuitable for study, or perhaps they are already known from other species?

good to hear you recovered from septicemia! Had that myself years ago, not from anything half as interesting as an expedition to Indonesia tho lol

thanks again for posting Brian!

[Rob_H]

Attacks on pigs and deer are extremely successful. About three quarters bleed out within the first thirty minutes and another approximately fifteen percent succumb within three or four hours. Repeated attacks by the same or other komodos is not uncommon. In dramatic contrast is the outcome of attacks on water buffalo. Which invariably get away, with deep wounds to the legs.

Bryan, there's no doubt you've shown the proximate components very well (let's be honest, that's a big understatement), but these sentences here, the ecological and adaptive components, are something that obviously hinges your entire argument together. I assume these statements about hunting efficiency are based on data you're writing up (or have you published this already?), in which case I'll hunker down with trepid anticipation ;).

There have been many examples in behavioural ecology where perceived importance from lab-based work simply fail to extrapolate to ecological reality, which is why many on the adaptive side of the fence tend to hold their breath before getting too excited with these kinds of studies. I hope you'll forgive why there are a few 'naysayers' for now until you show convincing foraging/field data.

It has been a man made artificial scenario all along that has nothing to do with the evolution of the predatory ecology of komodos

I see where you're coming from of course, but there are many examples of foraging that rely heavily on human introductions. A classic is tool-use in New Caledonian crows... one of the most sophisticated animal behaviours known, and yet the major current adaptive importance on tool use seems to be for extracting a beetle larva from a human introduced tree species.

Important in evolution? Who knows, but it's likely... these birds get around half their fat and protein from these larva. Important for current survival? Absolutely. Many people find both those questions equally interesting, so if Komodo's are getting a significant proportion of their diet from introduced buffalo that are carking it due to bacterial infections following a lacerating and venomous bite, then I guess who cares (except the mechanistic guys ;)) where the sepsis comes from.... a really cool functional question is whether the Komodo's have adapted their foraging ecology to accommodate this new food source. But if you're wanting to rule out Auffenberg et al's septic bite idea, then I just can't see how you'll do it convincingly without observational data showing bitten buffalo survive/don't get sepsis when they don't wallow.... Unless you get welfare approval for an experiment of course (little chance of that in the UK!).

And just for the record (this isn't directed at Bryan), there's nothing wrong with being a 'naysayer'. I'm sure venom is extremely important for these guys in the context specified (medium-sized mammal predation). However, disproving other people (i.e. the septic-bite brigade) obviously requires much more effort to be convincing, and it's something you need to live with when you're publishing controversial ideas in science. I personally think there's just one more (admittedly quite big) piece to the puzzle before everyone else comes crawling to the pedestal...

Cheers,
Rob

[MDT]

Great post Brian.....the components inducing hypotension and anticoagulation...has your team identified what they are? Do they correlate with any other venoms you have studied?

I ask because one of the most "complicated" envenomations I've treated (essentially all North American pit vipers, except this one) was a Gila bite. The patient developed significant hypotension requiring aggressive use of pressors and mechanical ventilation. He ultimately did well, but it was sketchy for several hours. Your statement made me wonder if there were any similar components...

[venomdoc]

Rob H, those numbers regarding relative predation/escape rate of buffalo vs pigs/deer are based not only on my own field observations from four expeditions to Rinca and Komodo but also congruent results from a larger sample size published by Tim Jessop from more trips to the same locales. So the numbers are solid. In this case, it is actually the field observations that stimulated the lab work, not the other way around.

[venomdoc]

MDT, yes we have published the toxins workup for komodos as well as other varanids as well as other anguimorpha lizards. The articles can be downloaded from my webpage www.venomdoc.com. However, this one hasn't been added to the page yet
http://www.venomdoc.com/downloads/2013_Fry_squeezers_and_leaf_cutters.pdf
All are linked there except the bacteria study which I haven't had a chance to update on the page yet. Here it is http://www.venomdoc.com/downloads/2013_Fry_Komodo_bacteria.pdf

[MDT]

Cool...I'll check them out. Thanks so much!

[smy_749]

MDT, yes we have published the toxins workup for komodos as well as other varanids as well as other anguimorpha lizards. The articles can be downloaded from my webpage www.venomdoc.com. However, this one hasn't been added to the page yet
http://www.venomdoc.com/downloads/2013_Fry_squeezers_and_leaf_cutters.pdf
All are linked there except the bacteria study which I haven't had a chance to update on the page yet. Here it is http://www.venomdoc.com/downloads/2013_Fry_Komodo_bacteria.pdf


Didn't have a chance to read through yet, but I noticed the list of bacteria. I had no idea there were so many present. Just about everything I studied in college and then some. And I'm a micro bio major.

[venomdoc]

Smy_749, key here is that it is nothing exceptional in regards to types or levels. A good lab could document as many in the mouth of family dogs or lions.

Bacteria-as-a-weapon is evolutionarily implausible since it would act too slow to be under any sort of selection pressure. If water buffalo had never been introduced to the islands, then this enchanting fairy tale about komodos selectively blooming bacteria in their mouth never would have been dreamed up in the malaria-fever restless nights of Auffenberg. He proposed the idea based upon a fundamental misreading of the biological reality rather than recognising the artificial situation for what it was. Introduced water buffalo trapped on small islands with only stagnant water holes has as much to do with reality as catapulting cows to great white sharks.

[venomdoc]

The next step in our research is to culture the watering holes. We will be sampling widely, not only on Rinca and Komodo islands but also in the native range of the water buffalo as well as in northern Australia where they have also been introduced. The below images illustrate just how putrid the water is and the sort of non-lethal wounds that the water buffalo are getting, that facilitates the entry of the bacteria from the disgusting water,

http://www.venomdoc.com/downloads/water_buffalo_I.jpg


http://www.venomdoc.com/downloads/water_buffalo_II.jpg

[MDT]

Brian, that last pic looks almost like a prolapse of (?)rectum/uterus/etc., rather than abscess or the like. Can you comment on what is going on in that pic?

Thanks!

[venomdoc]

Indeed, it is an excellent example of the sorts of wounds that occur when komodos attack. They do a unique 'grip and rip' mode, where by they bite and then use the strong forelegs and neck to pull straight back, with each tooth thus cutting in succession, resulting in four parallel deep wounds. In this particular event, it sliced him right in the butt. There are other cuts in the legs. He ended up dying slowly over the next week from septicemia. However, in the case of natural sized prey items, this can result in severed major arteries. At one of our field sites (Rinca Island) a young boy was killed this way, when his femoral artery was cut all the way through. He rapidly bled out.

[MDT]

Nice :)
I think I'd rather go by hemorrhage rather than by sepsis.....

I appreciate the info!

[Mikoh4792]

Indeed, it is an excellent example of the sorts of wounds that occur when komodos attack. They do a unique 'grip and rip' mode, where by they bite and then use the strong forelegs and neck to pull straight back, with each tooth thus cutting in succession, resulting in four parallel deep wounds. In this particular event, it sliced him right in the butt. There are other cuts in the legs. He ended up dying slowly over the next week from septicemia. However, in the case of natural sized prey items, this can result in severed major arteries. At one of our field sites (Rinca Island) a young boy was killed this way, when his femoral artery was cut all the way through. He rapidly bled out.

Do you have any details on how the accident took place? Did it chase the boy down? Was the boy walking along and happened to step on it's tail..etc?

[Gatorhunter1231]

Hello dr. Fry,
Congrats on all scientific adventures. I have had time to read your links to see if they give a break down of the enzymes, proteins, etc (AT&T works me like crazy). I have been aware of the anti-colagation agents related to varanus bites. Actually have have been on the receiving end several times.
What kind of potency are we talking about? In normal guy terms. I have been bite by v. Salvadorii many times and up to 5ft with anything major outside of large amounts of bleeding from teeth slicing through my skin (and gloves) like a hot knife through butter. Never had any skin deteration or anything that someone would picture to go with an envenomation.
I have had rabbits survive attacks from an 8ft v.salvadorii for a day and appeared they could live until infection. (I found rabbit and put out of misery). Major lacerations and major blood loss. I would venom could have easily pushed the rabbit over the age with the rabbit already at a weaken state but I had to put it down. A 40lb salvadorii vs 10 rabbit should be a lethal venom delievery when a 200lb Komodo's venom can drop a 500lb plus water buffalo. Sorry for any misspellings I quickly typed it down on my I-phone. Can't get scientific till Tuesday.

[venomdoc]

Key here, as I mentioned in my earlier post, is that the natural sized prey for Varanus komodoensis is 40-50kg. Water buffalo are well outside this range. So the bite effects (with mechanical damage as the primary effect and the venom there to supplement it) are mirrored in this. Please read my earlier post. As for your comments about what someone would picture for envenomation, in that local tissue damage must go with this, this is a view obviously coloured by the effects of viperid snakes which contain large amounts of proteolytic enzymes. In contrast, elapid snakes typically lack such enzymes. So there is no 'general bite effect' picture to be found even within the snakes. Venomous lizards typically do not produce local tissue destruction as they lack such large metalloprotease enzymes. Local pain and swelling may be present due to kallikrein enzymes though.

[murrindindi]

Hi Bryan, I don`t want to take away from the current discussion on V. komodoensis, but I`d like to ask if you have an opinion on whether the Mosasaurs and their closest relatives were likely to have been venomous, that would obviously make them the largest venomous vertebrates ever to have existed, rather than V. priscus?
Thanks in anticipation of a difinitive answer (rather than "it`s possible")! :)

[venomdoc]

Unfortunately when talking about paleontology, there is really no such thing as a definitive answer. While the Mosasaurs certainly appear to be varanoid, the relative placement is unclear. If they are in fact within the Anguimorpha, then they would indeed share a common venomous ancestor with the other anguimorph lizards. However, the envenomation strategy of these lizards would not be favored in a purely aquatic lifestyle since any venom would wash off from the open cuts or skin. This is in contrast to venom delivered via a puncture wound in the two independent lineages of marine snake (sea kraits and sea snakes) as well as cone snails or venomous fish. So Mosasaurs indeed emerged from within the venomous lineages, I suspect any venom system would be relicital, with powerful crocodilian-like jaws favoured instead for predation.

[venomdoc]

The last sentence should have read:

So if Mosasaurs indeed emerged from within the venomous lineages, I suspect any venom system would be relicital, with powerful crocodilian-like jaws favoured instead for predation.

[Rob_H]

Thanks Bryan. Follows is a lengthy reply summing up my perspective in more detail (although at the risk of repeating myself).

These seem to be the points you’re arguing:

1) Komodos use venom to kill their prey

2) Predation facilitated by sepsis cannot occur through inoculations from Komodo bites.

3) Predation facilitated by sepsis comes instead via the pathogens in the water-holes the buffalo live in following a lacerating Komodo bite

4) Pathogenic bacteria found in the mouths of Komodo’s are obtained from the environment where natural predation occurs, so they cannot be important in their foraging ecology.

5) sepsis-facilitated predation, from whatever source, is caused by human-introductions, so has not had enough time for selection to operate on, and is therefore not important.

6) Sepsis works too slowly to function as the primary means of disabling prey, as most animals have likely run off before the Komodo can catch them.

I’ll quickly address these in turn.

1) You’ve shown mechanistically that this is very possible from your great lab work. But no one has yet shown whether venom is important functionally. If you’re referring to Tim Jessop’s published predation observations from his PLoS One 2010 paper, this only involved 17 predation observations, none that involved buffalo, and with no analysis of whether venom or sepsis was killing the animals. Since no field study has been done on the functional importance of venom in Komodos in a natural setting, it is therefore, by definition, still speculation.

2) The current evidence for this is that oral swabs taken from Komodos in a natural setting contain bacterial flora that can cause sepsis; these flora do not spontaneously colonise except in the environmental context where natural predation occurs (acknowledged by Auffenberg); observations of Komodos predating animals with sepsis following a bite are common; no study to date has investigated whether animals such as buffalo will die if bitten by a Komodo without bathing in nasty water, which is necessary to confirm/dismiss this claim.

Again, I and many other’s would conclude that totally dismissing the role of septic bites in Komodo predation requires field data to be convincing. There is currently more evidence for it than not.

3) This is very convincing, and I doubt anyone would argue that this doesn’t contribute to how Komodo’s kill prey items such as pigs and buffalo that frequently wallow.


4) Maybe I don’t understand this one, but there are tonnes of examples of evolutionarily important adaptations that must be obtained from the environment (poisons, pheromones, scent mark compounds, digestive aids). Maybe the point of this argument, and your recent paper, has escaped me…. If you’re arguing that Komodos don’t therefore have any evolutionary adaptations to facilitate colonisation by these bacteria then I don’t think this is the best study to have addressed that.


5) This is simply a misnomer. There are many, many published examples of species responding to selection in response to human introductions (see my previous example, and a good review is: Strauss et al (2006) Evolutionary responses of natives to introduced species: what do introductions tell us about natural communities? Ecology Letters). Some of the best examples of this are in fact lizards (Anolis, Podarcis etc), where measurable responses to selection can be found in less than ten generations. Either way, an evolved response does not detract from whether a behaviour or trait offers a fitness advantage now.

6) I see exactly where you’re coming from: obviously it must be unlikely to evolve since there are few (any?) examples apart from Komodos, but again…. No field data! I don’t need to tell you that we’re talking about an animal with a highly developed olfactory system that is famed for tracking carcasses and prey from long distances…. If there is one species that is likely to be able to use a method of predation that takes days to kill large prey items, then Varanids are probably right up there.



As far as the current evidence is concerned, there is a very strong story that Komodos and many other Varanids are venomous, scant to no scientifically presented evidence that any species use this venom functionally when killing their prey, and absolutely no evidence, in my mind, that Komodos do NOT use bacteria as a ‘venom’ when killing prey.

I have no agenda in regards to whichever hypothesis is accepted, but I do believe people need to be particularly rigorous when discrediting previous hypotheses and the scientists that proposed them.

Hence my suggestion that the most important component you now need is field data (no matter how difficult it is to collect) to disentangle the role of bite-inflicted trauma, venom, and sepsis in the foraging ecology of these animals to advocate the role of venom, and discredit Auffenberg’s suggestion for the role of pathogenic bacteria.

Cheers,
Rob

[venomdoc]

1) Key is that water buffalo always escape. They flee quite some distance from the attacker. Thus if and when the buffalo dies, the original dragon is very unlikely to be the beneficiary. Thus there would be no selection pressure operating upon such a predation strategy as nature does not run a charity

2) Actually, the evidence does not support this at all and indeed the Pasteurella multocida section was the weakest part of the Montgomery study. Pasteurella multocida is part of the normal oral flora of dogs, cats, and other animals and is only associated with infection when outside its usual ecologic niche. Montgomery et al.33 proposed P. multocida as the cause of Komodo-associated prey sepsis and mortality, even though it was reported in only 5% (2/39) of their dragons. Although infections from this in bite wounds of mammals may be on occasion pathogenic, they are associated with sepsis infrequently. At best this species can be called an opportunistic pathogen that given time in the right environment in a wound would be serious and perhaps lead to eventual death but are in no way pathogens in the sense we regard Strep pyogenes, Staph aureus, gangrene-causing bacteria

The rest of the gram-negative organisms that they isolated are commonly found in soil and water. They also found 29 gram-positive species, 25 from wild and eight from captive dragons; most were staphylococci and streptococci that are typically found on animal skin, as well as Bacillus spp., that are commonly found in soil and on vegetation. They considered 54 of the 57 species to be ‘‘potentially pathogenic’’; however, these members of the normal microbiome are in fact of low virulence and unlikely to be the cause of rapid fatal infection when present in a wound.

So the extreme variability of bacteria present in the wild dragons argues against a use since there is obviously no selection pressure at work, combined with the fact that even in the wild dragon study the types of bacteria present were quite ordinary. The difference between our study and theirs was that I involved clinical microbiologists in mine, thus there was no over-reaching as to the nature of the bacteria present.

3) it is an artificial situation so it has zero relevance to the evolution of predatory behaviour

4) If komodos were in fact evolutionarily selected to facilitate the growth of bacteria in their mouth, then there would be a consistent trend as to the types and levels of bacteria present. Instead, the wild and captive studies both showed simply the normal types of transient oral flora expected to be found in the mouth of a lion or the family dog. There was the expected levels of extreme variability in species present. If they were indeed cultivating it, then there would be evidence of evolutionary selection but this was conspicuously lacking.

5) there is no fitness advantage to be gained if the biting animal does not obtain the prey. It is not like there is a komodo dragon charity at work with water buffalo bodies dropping all over the island. It is actually a quite rare event.

[venomdoc]

6) regarding field observations, of all the extensive tracking and filming of komodos, there has never been a single documented case of the same komodo biting a water buffalo and following it until it dies.

[MDT]

2) Actually, the evidence does not support this at all and indeed the Pasteurella multocida section was the weakest part of the Montgomery study. Pasteurella multocida is part of the normal oral flora of dogs, cats, and other animals and is only associated with infection when outside its usual ecologic niche. Montgomery et al.33 proposed P. multocida as the cause of Komodo-associated prey sepsis and mortality, even though it was reported in only 5% (2/39) of their dragons. Although infections from this in bite wounds of mammals may be on occasion pathogenic, they are associated with sepsis infrequently. At best this species can be called an opportunistic pathogen that given time in the right environment in a wound would be serious and perhaps lead to eventual death but are in no way pathogens in the sense we regard Strep pyogenes, Staph aureus, gangrene-causing bacteria

The rest of the gram-negative organisms that they isolated are commonly found in soil and water. They also found 29 gram-positive species, 25 from wild and eight from captive dragons; most were staphylococci and streptococci that are typically found on animal skin, as well as Bacillus spp., that are commonly found in soil and on vegetation. They considered 54 of the 57 species to be ‘‘potentially pathogenic’’; however, these members of the normal microbiome are in fact of low virulence and unlikely to be the cause of rapid fatal infection when present in a wound.

So the extreme variability of bacteria present in the wild dragons argues against a use since there is obviously no selection pressure at work, combined with the fact that even in the wild dragon study the types of bacteria present were quite ordinary. The difference between our study and theirs was that I involved clinical microbiologists in mine, thus there was no over-reaching as to the nature of the bacteria present.

Exactly....I have treated multiple canine/feline bites (never a varanid :) ) and to my knowledge, none of them have resulted in sepsis. Pastuerella is the predominant org in a feline bite. But there are also numerous others as well (both aerobic and anaerobic). Bites happen frequently and sepsis does not.

It does strike me as an opportunistic situation and not the primary causation for the death of the prey.

[murrindindi]

and absolutely no evidence, in my mind, that Komodos do NOT use bacteria as a ‘venom’ when killing prey.
Cheers,
Rob

Hi again, I`d like to ask for the evidence they DO use bacteria as a "venom", hasn`t this already been explained in some detail?
Just asking, it`s been a very interesting discussion so far! :)

[venomdoc]

Despite the ubiquitousness of this concept in nature 'documentaries', there has been a shocking lack of evidence to back it up. It was a concept by Auffenberg that was never tested and instead accepted as gospel. Science-fail.

[venomdoc]

As the saying goes 'extraordinary claims require extraordinary evidence' and bacteria-as-a-weapon would be an unprecedented form of predation strategy. Yet, despite this, it was not previously examined critically. It was instantly accepted because it was enchanting... just like most fairy tales.

[infernalis]

Despite the ubiquitousness of this concept in nature 'documentaries', there has been a shocking lack of evidence to back it up. It was a concept by Auffenberg that was never tested and instead accepted as gospel. Science-fail.

I concur. Absolutely everything makes sense here.

What is interesting is that it's all so simple that I am surprised that no one questioned the whole bacteria theory previously.

In the documentaries, they always show the water buffalo going straight to those filthy watering holes, how is it no one ever questioned this before?

There was a young man I went to school with, he slipped in a barn and scraped his shin on a manure trough. He did not seek medical attention, within a day his fever shot up to lethal levels and within a few days of the scrape he was pronounced dead.

[murrindindi]

As the saying goes 'extraordinary claims require extraordinary evidence' and bacteria-as-a-weapon would be an unprecedented form of predation strategy. Yet, despite this, it was not previously examined critically. It was instantly accepted because it was enchanting... just like most fairy tales.


Walter Auffenberg was the leading "expert" on komodoensis (he`s done some great work), his assertions were the "proof", no need to question or test too thoroughly, it made sense?
At one time komodoensis was thought to be almost blind and deaf (Attenborough), though now we know that`s not true at all...
Then you come along with your detailed scientific studies and spoil the whole thing as far as the bacteria "venom" brigade are concerned... (Sincere thanks)!! ;)

[infernalis]

Walter Auffenberg was the leading "expert" on komodoensis (he`s done some great work), his assertions were the "proof", no need to question or test too thoroughly, it made sense?
At one time komodoensis was thought to be almost blind and deaf (Attenborough), though now we know that`s not true at all...
Then you come along with your detailed scientific studies and spoil the whole thing as far as the bacteria "venom" brigade are concerned... (Sincere thanks)!! ;)

Bryan is in league with the dark lord, burn him!:D

[murrindindi]

Bryan is in league with the dark lord, burn him!:D


Do you have scientific evidence for that assertion Wayne (other than purely circumstantial and everything points to it)???? :suspicious:;)

[infernalis]

I shall need no proof. The prophets warned of such blasphamy! ;) :D

BBC NEWS | Science & Environment | Komodo dragons have venomous bite (http://news.bbc.co.uk/2/hi/science/nature/8056040.stm)

[murrindindi]

It`s said the Komodo dragon has a relatively weak bite force, and compared to some animals that`s true, though 600lb sq. inch (tested) is still a hard bite (that`s about the same as a lion), and I wouldn`t want to get bitten by one of those either (even without the venom)!! :no: ;)

[infernalis]

It`s said the Komodo dragon has a relatively weak bite force, and compared to some animals that`s true, though 600lb sq. inch (tested) is still a hard bite (that`s about the same as a lion), and I wouldn`t want to get bitten by one of those either (even without the venom)!! :no: ;)

Absolutely.

I would not want to be bitten by your monitor either Stefan...

[mdfmonitor]

These dragons know who's boss in their environment, a well heated hungry captive monitor will have a go at anything, so it seems reasonable to think that a hungry king komodo will just have a go, just in case they get a reward.

I can't see why a komodo would follow a possible prey item round unless it knew the prey item time was very near, waste of energy, sit in the bushes wait for that smell of death to be blown across on the breeze or something they can jump out at.

their powerful bodies are built for one thing only!!

[murrindindi]

These dragons know who's boss in their environment, a well heated hungry captive monitor will have a go at anything, so it seems reasonable to think that a hungry king komodo will just have a go, just in case they get a reward.

I can't see why a komodo would follow a possible prey item round unless it knew the prey item time was very near, waste of energy, sit in the bushes wait for that smell of death to be blown across on the breeze or something they can jump out at.

their powerful bodies are built for one thing only!!


They aren't just "sit and wait" predators, I`ve seen them (on film) openly chasing deer that had previously been bitten for what looked like several hundred metres. They can run for some distance at their maximum speed (at least 400m), that`s some stamina for a "simple, primitive reptile" as they were once thought to be. Of course they aren`t "simple", far from it, very sophisticated and advanced in many ways.

[mdfmonitor]

Their endurance & intelligence is amazing compared to a corn snake, but not so amazing compared to a wolf.

from the vids i've watched they usually lunge at their intended prey items & inflict hopefully enough damage in order to slow their prey items down, so they can then chase them down.

For me their intelligence is learned through food/breeding & surviving, i'm sure they have a social pecking order, but not to the extent wolfs have etc, so to me these amazing creatures are raw bull headed creatures that can strut their stuff.

A healthy monitor walks with attitude & when large enough is mostly fearless, that's when monitors like niles fall victims to crocs raiding croc nests, that's why we see monitors fighting with wild cats & tail whipping lions on youtube vids.

Their learning is at a slower pace than a dog etc, i'm just starting to witness that young argus remembering where they found previously after 12 weeks ( i'm longer handing the food on a plate ), they smell food & go back & look in the same place as the prey items was previously found the night before.

In the vid i just posted (a previous post) one of the clips the monitor has a 2 foot wall to climb to grab the mouse, she/he jump once & looked then accessed & decided to run up the easy way, 3/4 weeks ago she'd been jumping like a mad hatter at the 2 foot of ply. :)

these are amazing creatures but they will always be placed in a certain place on the intelligence & endurance ladder, assuming they've had opportunities to develop their brains!

stuck in a small bare cage fed dead mice at the same time every night, what chance do they have to learn compared to their cousins living wild which when they make mistake their dead or starving.

Komodo dragon it doesn't make sense why they'd need to use venom with the body they pack, don't make sense for them to chase miles & miles after prey items when they have the intelligence to pick a sure bet & sense a sure bet miles away that's dead or well on the way to dying.

just my thoughts means nothing at end of the day! :)

[murrindindi]

Komodo dragon it doesn't make sense why they'd need to use venom with the body they pack, don't make sense for them to chase miles & miles after prey items when they have the intelligence to pick a sure bet & sense a sure bet miles away that's dead or well on the way to dying.

just my thoughts means nothing at end of the day! :)


Hi Mark, I believe wolves often chase prey for significant distances (literally miles), with their obvious intelligence you`d think they`d pick the sick and dying animals and not chase anything anywhere!? Isn`t intelligence strange (glad I don`t have much).... :)
The Komodo dragon`s venom helps them dispose of their usual prey in a very short space of time, surely that`s a great addition to their arsenal?

[mdfmonitor]

Hi Mark, I believe wolves often chase prey for significant distances (literally miles), with their obvious intelligence you`d think they`d pick the sick and dying animals and not chase anything anywhere!? Isn`t intelligence strange (glad I don`t have much).... :)
The Komodo dragon`s venom helps them dispose of their usual prey in a very short space of time, surely that`s a great addition to their arsenal?

Didn't Dr Fry say that these enzymes can be found in most saliva such as dogs etc to some degree (i'm not reading it all again) & don't we use the same process to help our digestion!! but is more rapid in rattle snakes digestion etc.

if that's not what was said i'm getting out whilst the going is good!! :)

[venomdoc]

>Didn't Dr Fry say that these enzymes can be found in most saliva such as dogs etc to some degree (i'm not reading it all again) & don't we use the same process to help our digestion!! but is more rapid in rattle snakes digestion etc.

No, I was talking about the bacteria. Separate conversation entirely.

[mdfmonitor]

>Didn't Dr Fry say that these enzymes can be found in most saliva such as dogs etc to some degree (i'm not reading it all again) & don't we use the same process to help our digestion!! but is more rapid in rattle snakes digestion etc.

No, I was talking about the bacteria. Separate conversation entirely.

I've re-read your postings, my point i was making generally was venom/saliva is not needed for the komodo dragon to be an effective predator in it's natural environment.

Thank you for taking the time to post!

[murrindindi]

Hi again Mark, I hope Bryan will respond to your comments himself.
My thoughts are that the venom is needed, without it they wouldn`t be able to attack and kill with nearly as much success as they do now, they would only have a slashing bite, that would not necessarily cause such heavy blood loss and shock which must make it less likely the usual prey will escape (less energy needed chasing/searching for the injured animal). That`s a very useful and efficient addition to their "weaponry" to my mind.

[Gatorhunter1231]

I stated already I have seen rabbits survive bleed out and shock from v.salvadorii. I haven't looked at a taxonomy chart lately but I believe v.salvadorii is second closest relative (maybe third, not sure where v.giganteus falls) with v.varius being the closest. Shouldn't the venom kill the rabbit (well with normal prey size).
Never been bite by a Komodo or lace monitor but croc monitors need no extra help in that department. Not saying the venom doesn't exist or the proteins and enzymes but wonder if we are just giving it to much credit when animals that are attacked are dying from exhaustion, blood loss, and infection instead.

[MDT]

I think the question that you guys need to ask is "what am I expecting from envenomation?"... If you're expecting the prey item to wither and die as it would from an elapid or viperid source, then your definition of envenomation may need tweaking.

[venomdoc]

As I have stressed on multiple occasions the venom is there in a supporting role to the teeth, that it is but one part of the combined arsenal. The primary weapon are the teeth and the very deep wounds inflicted by them. The venom keeps the blood from clotting, drops the blood pressure further and also helps induce shock.

In the case of V. salvadorii, the fact that you have seen rabbits survive is meaningless because you are giving it a larger animal than it would be predating on in the wild. In addition, the unnatural encounter in a cage with a very different sort of animal than it would encounter, may not elicit the same hanging-on and chewing that would be the case in the wild. Unlike a snake, the venom is not delivered instantly but requires more contact time. MDT was spot on in pointing it is a horse-for-courses scenario and requires a broadened appreciation of the diversity of venom systems.

[murrindindi]

I stated already I have seen rabbits survive bleed out and shock from v.salvadorii. I haven't looked at a taxonomy chart lately but I believe v.salvadorii is second closest relative (maybe third, not sure where v.giganteus falls) with v.varius being the closest. Shouldn't the venom kill the rabbit (well with normal prey size).
Never been bite by a Komodo or lace monitor but croc monitors need no extra help in that department. Not saying the venom doesn't exist or the proteins and enzymes but wonder if we are just giving it to much credit when animals that are attacked are dying from exhaustion, blood loss, and infection instead.


Hi, why should the venom have to kill the rabbit (or any other prey), if it just helps to incapacitate the animal in some way surely it`s of benefit to the dragon (and other species)? There are many animals that are only mildly venomous, does that mean the venom is of no use to them?
V. salvadorii have the longest teeth, that doesn`t necessarily mean venom would not be of use to them. They have a considerably smaller body size than an adult komodoensis and can`t attack and bring down similar sized prey (even with venom).
It`s mainly the Water buffalo that die from infection/exhaustion, etc, but they are not the most important (most frequent) prey animal.

[Gatorhunter1231]

Doesn't have to die. However the examples I've seen say the animals wonder off and die. Outside of extra blood loss, what key roll is the venom doing that causes death on the attacked animals. Lots of things have venom-hemotoxins and neurotoxins being what I relate to. One shows tissue damage and other shutting down the nervous/cardiovascular system (just simple examples). Varanus venom has anti-collagation effects. I just have not witness anything beyond that. I give it that credit all day.

[Gatorhunter1231]

V .salvadorii have been seen feeding on tree kangaroos (not confirmed whether they are scavenging or attacked and killed) Which are larger then a 5lb rabbit.
I 100% don't disagree dr. Fry with your statement above.
I was looking for more details as far as how it aids. Which you stated above. Just seemed a little vague to say it aids in bloodloss, shock, etc. looking for a better breakdown on how it played out after the venom was chewed in.

On another note. Someone already said it early but this really is one of the nicest forums around-rarely does anyone actually get hateful for resort to name calling.

[venomdoc]

I agree Gatorhunter that this forum is a rare breath of fresh air. Indeed this is the first time I have posted on a forum for years because of the rampant ****wittedness that has inflected most others!

As for the breakdown on how it works, as we only recently discovered the venom there is much work yet to be done. I have an enthusiastic PhD hard at work on the lizard venoms :)

[Gatorhunter1231]

Ahh now we are on the same page Dr. Fry. I just got stuck at venom being the cause of death on animals that got away after an attack. You clearly stated it aids and how. I know my examples sucked as far as what you worked with in the field but it was what I had to relate to. May your research bring you more success and ill be waiting to read the detailed version on the venom soon :).

[B_Aller]

Sorry if this was covered, just joined and read this thread, but what about the pigmy elephants that once inhabited these islands? I was under the impression that Auffenburg suggested that they were an early prey source, besides, I can't be the only one who envisions a fight betwixt KD's and pigmy elephants! And what about megapodius? They're not huge but there is a known relationship between the two species right? Don't they ever chomp them down? Wouldn't the bacteria or venom help with the predation of megapodius?
Hi Bryan! The offer to study dumerilii offspring is still open, would love to find a way to send you a clutch of babies.
Best.
Ben

[venomdoc]

Hi Ben,

It was Jared Diamond who proposed komodos evolved as giants to predate on pygmy elephants. However, this was before komodo fossils were discovered in Australia showing the Aussie origin. However, very young pygmy elephants may have been fair game.... as would the 'Hobbits' Homo floresiensis.

[B_Aller]

very young pygmy elephants may have been fair game.... as would the 'Hobbits' Homo floresiensis.

NOW we're talkin' I've just never been able to get past the visual of KD's and pigmy elephants going at it, too many cartoons as a kid I guess.
Considering the Aus origin, my flightless bird idea may not be that crazy after all!
Best

[smy_749]

Thats an awesome picture. I don't suppose you have any pictures of komodo's big cousin hunting down hobbits as well do you?

[infernalis]

NOW we're talkin' I've just never been able to get past the visual of KD's and pigmy elephants going at it, too many cartoons as a kid I guess.
Considering the Aus origin, my flightless bird idea may not be that crazy after all!
Best

Megalania.

Now that was a lizard.

[infernalis]

Slaying The Dragon | Forensics, Fossils and Fruitbats (http://forensicsfossilsfruitbats.wordpress.com/2013/07/07/slaying-the-dragon/)

[mdfmonitor]

Just watched venom island (Dr Fry) & it shows why venom comes in very handy when the komodo dragon is hunting!! very interesting program, worth watching if you haven't seen it! :)

[infernalis]

Thanks Mark!!

Venom Islands | Smithsonian Channel (http://www.smithsonianchannel.com/sc/web/show/3357375/venom-islands)