Reptile & Amphibian Forums

http://news.yahoo.com/s/nm/20051116/hl_nm/science_venom_dc

learn something every day!

Little skeptical, but then again, what do I know.
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hbailey

0.1 argus monitor

>>Little skeptical, but then again, what do I know.
>>-----
>>hbailey
>>
>>0.1 argus monitor

There is a bit more information at the link below.

Cheers
Bryan
Early evolution of venom in reptiles

-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

The irony for me is that the controversy is about venom. The point of this model may be that evolution happened. This seems like good science.
Jim

All snakes and all lizards, have glands the secret saliva, some snakes modified some of these glands into venom glands(specialized).

Consider, salvia is somewhat toxic in all animals. Human salvia is known to be very dangerous. Somewhere there needs to be a line what dictates the difference between salvia and venom.

In a case like this one, Monitors salvia has properties that act in a certain way, but normally its not delerious to man. That is normally the difinition. If its normally delerious to man, then its venom.

For us that have had experiences from bites of reptiles, we already know, they bleed more then a normal puncture of equal size. This is true with bites from cornsnakes and kingsnakes, etc.

As a person that has experienced bites from many monitors(wild and captive), harmless snakes, beardeds(both wild and captive) Iggies(both wild and captive) and rattlesnakes(only wild). I will say, all the above do not compare in any way to rattlesnakes. Theres a difference as great as a firecracker to an 500pd bunker buster. Both the firecracker and the bunker buster are the same. Yes??????? So if their saying monitors are venomous like rattlesnakes, they are totally nuts, and in great need to find something more constructive to write about. But then again, they may be right, I know for a fact, my mother-in-law is venomous. FR

G'day Frank,

The key here is the evolutionary context. For the animal, its all about prey capture. Anything to us is a pleasent side-effect. However, monitor lizard bites can cause effects, particularly if its a full-on feeding chomps. When we were writing it all up, we even stumbled upon some Russian literature reports from decades ago commenting about bite effects from V. griseus and even writing up expirements they did showing they could paralyse birds. Fascinating.

As far as the gland. The venom gland has no homologous structure in nature. It is a newly created gland, with the mandibular and maxillary regions (lower and upper jaw respectively) arising from the mucus glands that extend along both regions.

Thats the primitive state and what has been retained in Iguania, where both the mandibular and maxillary glands are thin and simple in structure. Pretty much what you would expect.

The primative snakes have both the mandibular and maxillary glands but accompanying changes of skull architecture, the advanced snakes ended up favoring the maxillary venom gland, developing it into a very complex structure including sealing it (encapsulation), making it hollow (developing a lumen) and running ducts to the teeth. From there, further evolutions included the develpment of hollow fangs (which has occurred on three separate occasions in the snakes (Atractaspididae, Elapidae and Viperidae).

In the anguimorpha (anguiids such as Gerrhonotus, Heloderma, Ophisaurus, Varanus, Xenosaurus), the mandibular gland has become very highly developed, including being completely encapsulated, has a well developed lumen and has large ducts leading to the base of the big teeth on the lower jaw.

Milking was as easy as giving the side of the lower jaw a gentle squeeze and watching the liquid pool at the base of the teeth. Using this and other tricks we could get up to 40-50 milligrams per milking of one of our large monitors. We've looked at a dozen species so far and yeild has been proportional to the size of the glands. V. varius is a great yielder, our Perenties are also pretty impressive but even our little species like V. eremius or V. baritji put out good amounts (4 milligrams per milking).

The other part of the equation is whats in there and what are they doing with it.

In agamids like the bearded dragon, not much comes out. The mucus cells occupy most of the available space and the vascularisation is not too much. What does trickle out though is still undergoing molecular evolution at a tidy rate. For example, we sequenced several very divergent crotamine toxins from both the mandibular and maxillary glands of the bearded dragon (the buggerall type of gland). Crotamine toxins are one of the hallmarks of rattlesnake venoms. The toxins were as different from each other as they were from the rattlesnake forms. We are currently exploring the different bioactivities of the peptides.

In the varanids, however, things are really cooking along. The venom was a complex as any snake venom I've looked at. It was quite stunning actually. I expected it to be much simpler than my taipans or death adders for example. Its more complex than a lot of colubrid snakes with well developed venom glands. The activities were also quite diverse. It hammers the blood pressure, blood coagulation and really jacks up the pain sensitiivity. Exact same stuff as has been widely charcterised in snakes as really hammering prey, incapacitating them by painful cramping, rendering them unconscious and then the slower but more lethal toxins can do their job. Or the varanid could continue shredding them with their very impressive teeth. If you have large cutting teeth, it'd be a good thing to have something to accompany it that causes the prey to feel pain much more (impacting its ability to defend itself), causing severe cramping, prolongs bleeding from the deep teeth wounds and brings about unconciousness.

Remember, the evolution of venom is all from the point of view of the prey item. Speaking of which, this single origin of venom in reptiles 200 million years ago, coincides with the growing abundance of the mammaliaform (e.g. Sinoconodon, Morganucodon and Hadrocodium). A nice bite sized prey item. Very tidy.

For some picture of the glands, follow the link below

Cheers
Bryan

>>All snakes and all lizards, have glands the secret saliva, some snakes modified some of these glands into venom glands(specialized).
>>
>> Consider, salvia is somewhat toxic in all animals. Human salvia is known to be very dangerous. Somewhere there needs to be a line what dictates the difference between salvia and venom.
>>
>> In a case like this one, Monitors salvia has properties that act in a certain way, but normally its not delerious to man. That is normally the difinition. If its normally delerious to man, then its venom.
>>
>> For us that have had experiences from bites of reptiles, we already know, they bleed more then a normal puncture of equal size. This is true with bites from cornsnakes and kingsnakes, etc.
>>
>> As a person that has experienced bites from many monitors(wild and captive), harmless snakes, beardeds(both wild and captive) Iggies(both wild and captive) and rattlesnakes(only wild). I will say, all the above do not compare in any way to rattlesnakes. Theres a difference as great as a firecracker to an 500pd bunker buster. Both the firecracker and the bunker buster are the same. Yes??????? So if their saying monitors are venomous like rattlesnakes, they are totally nuts, and in great need to find something more constructive to write about. But then again, they may be right, I know for a fact, my mother-in-law is venomous. FR
Gland pictures

-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

We have been very careful to stress the fact that this is venom from the point of view of prey capture. Their threat level to humans would be on par with some of the colubrid snakes perhaps such as a decent sized goanna being on par with a large Boiga or something like that. Totally different composition in what they are putting out but taking all that into account. You might notice a good one but your not going to fret about it. The twenty gram mouse, however, would take a bit mroe of a beating

Cheers
B
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

it is from a feeding response. I have never had the reactions you mention. I have had them chewing on my hand or arm without any effects other then bleeding and normal pain from being bit (of course it doesn't tickle). I have had throbbing of my hand but nothing different then when the Dr. pricks a finger to take blood.

One of the nice things about a big goanna bite, you're typically more concerned about the teeth that just scraped along the bone Lovely sensation.

As for bites, its much as the colubrid snakes that lack the high pressure delivery system, its not as efficient as that of a hollow-fanged snake. Same sort of principle for the goannas, people also have dry bites from gila monsters.

Its interesting though to read old journal reports or talk to keepers and get their experience. Here in Oz people have often remarked that the small goannas (kingorum, scalaris and such) can really sting. There was even a report here in the monitor forum a few weeks back about an interesting reaction from a savannah bite (pasted below).

Cheers
B

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Posted by: TrpnBils at Sun Oct 2 18:52:41 2005 [ Report Abuse ] [ Email Message
]
I want to get some opinions from people who keep monitors. I had one
hell of a weekend...
The Sav was dumped on me about a month ago as a rescue case. He's
2 years old but was neglected and is only about 17" long. Fecal came
back negative about a week or two ago. He's fairly aggressive, and I've
been bitten about half a dozen times or so with no ill effects other than
pain and a little blood. On Friday night, he got me real good on the arm
but didn't cause me to bleed or anything. About 20 minutes later I had a
bad sore throat, my chest and back hurt, and my neck was stiff. I figured I
must be getting sick or something, so I went to bed around 11:00. At
1:00am, I woke up and literally every square inch of my body from my
head to my feet was bruised, my tongue was swollen, and I was having
trouble swallowing.
I went to the ER (off topic, but they told me the parking lot was closed, so
I had to park 3 blocks away and walk. I was not happy). They didn't do a
thing for me. The only known allergy I have is antihistamines, which didn't
help the situation because they apparently couldn't give me anything else
to help. Luckily, everything started to get a little better on its own. The doc
went and did some "research" online (and called poison control, and if I
may say so: WTF!?), came back and asked me AGAIN what kind of lizard
it was. I told her it was a savannah monitor, so she asked me if it was
black with orange beaded skin. I think she did a search on venomous
lizards and thought I had a beaded or a gila monster....I dunno. To sum it
up, they said that they couldn't confirm it was the bite that caused the
reaction, but they had no idea what else it could've been. I'm pretty much
fine now, just a little sore and the bite itches, but that's it. I can't risk a
worse reaction, so I'm trading the Sav for something else hopefully later
this week.
A little background on myself - LIke I said, he's bitten me before, with no
reaction on my part. I've been bitten by wild and captive snakes several
times with no reaction on my part. I've been bitten by other lizards
(Tokays, and prehensile-tailed skinks most notably) with no reaction on
my part. I'm a part-time reptile keeper at the local zoo, so I come in
contact with all sorts of herps on a daily basis, and I've never had any
kind of reaction to a bite from any animal before.
So here are a few questions I've been trying to get answered, and
hopefully somebody here can help:
1) I'm assuming this will happen again at least as bad, if not worse, if this
lizard were to bite me again. Should I expect a similar reaction to a bite
from another monitor?
2) Same as above, except should I expect this from ALL reptile bites for
any reason now? If so, there goes my job and my hobbies.
3) I'm going to see if I can get a prescription for an Epi-pen in case this
happens again, but since they couldn't 100% confirm that this was the
result of the bite, I may have to do some research to prove a point. I
looked online and found limited info, and I've been talking to other
herpers at work and they tell me that monitors and skinks in particular are
well known carriers of some nasty stuff in their saliva. Is this true for
monitors any more than it is for other species of lizards or snakes? If so,
what is it that's in their saliva?
4) I'm just curious, has anything like this happened to anyone else with
monitors?
I'm at a loss for what to say because I REALLY hope this isn't something I
need to worry about with every reptile I touch for the rest of my life. I'm
just trying to get some answers, so any info you guys can give me is
greatly appreciated.
Thanks
-Jeff-

I have had alot of dry bites then.

As for the example you showed many people can have an allergic reaction to saliva from any animal bite. I know I have been bitten many times, and I believe Frank mentioned being bitten with little to no reactions. The cases of people telling me had a reaction are far out weighed by those you haven't.

>>As for the example you showed many people can have an allergic reaction to saliva from any animal bite.

Those effects were entirely inconsistent with either bacteria or allergy. If that had been a colubrid snake and reported to us as a case, we would have certainly chocked it up as an enveomation.

Cheers
B
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Is like this,

In this case, its salvia. But if I were 2grams, I would be dead from the venom. But then, If I were 2grams, I would be dead from the bite. Cheers FR

Glad I am not the only one who gets all the love around here.

Good thing we are not 2 grams.

This is a regular occurance with this beast..

Whether or not its venom is not situationally dependent. A sublethal bite from a cobra is not saliva for example.

As I mentioned, these glands are not homologous to saliva glands such as the submandibular gland, there is no homologous structure that exists. Rather the maxillary and mandibular glands are specialised gland evolutions for a discrete function.

Cheers
B
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

I am not disagreeing with you about glands or scientific discoveries. Except it was already commonly known. Heck, there are old threads on here, discribing the effects of monitor bites and excess bleeding. That there are glands that kinda different then other saliva glands, is sorta neat, but there are many different kinds of salvia glands with different salvia makeup. But all thats fine.

The point is in simple laymans understanding. A Cobra bite is usually delerious to humans, that a dry bite did not cause symtoms is does not change that. I have had five or so, dry bites(rattlesnakes), but that did not change or alter the two hot bites(darn it). The rattlesnakes are still venomous, which is assoiated with danger to the laymen(common understanding). Such things as our spotted night snakes, hognose snakes, blackheaded snakes, lyresnakes, ringnecks, vinesnakes, etc, contain venom that kills their prey. In some cases like the spotted night and vinesnake, kills their prey really dead and really fast. I am sure there are many many other species as well. I would imagine, and I was taught that, truely venomous snakes evolved from somewhere, and these less effective venomous snakes were a stepping stone. But they are still harmless to man. As are many of your elapid species in oz(thank goodness)

The only problem I have with your new difinition of venomous is, when in the hands of misguided people(the world is full of them) it is only one more tool to exercise power and control over things they do not understand.

It is far better to consider varanids(in this case) harmless to humans, and base their delerious powers on size, then on something that has not shown to be a problem, salvia or venom. You see, I know you understand the difference, but our government/s will not bother to make that distintion. All our arguements will not help(even if you help) because now they have scientific proof. Cool huh. Also how many little ozzie monitors are going to get their little harmless heads wacked off because your articule gets published and spread around the outback. You do understand your discovery does no real good unless their salvia or venom is of medical use. Other then that, it merely creates more fear and more misunderstanding.

For instance, I know of 5 or 6 totally undiscribed monitors in Australia, but if no one knows of them, they will not be harassed or collected or bothered. I am sure sooner or later, they will be discovered, then they will be harassed senselessly. Poked, proded, preserved, collected, poached, etc. well meaning or not. Some things are better unknown. The pic is an example, I saw over 50 of these, they have a distinct range and color. Thanks FR

Hi mate

I understand where you're coming from an entirely sympathise. There are already too many assinine herp laws springing up (particularly in the US). Some places even ban geckos! Completely ridiculous. I'm of the opinion that anyone should be able to keep anything. Some animals, like venomous, should only be kept after training so a permit system like Florida's is a very rational approach. In regards to varanids now being lumped under venomous laws, this would be totally inappropriate (and something we've gone to great pains to stress). Its very much the same scenario as a couple years back when we showed that common colubrid snakes such as racers actually put out small amount of highly neurotoxic venom. One or two milligrams is fantastic for a Coluber to stun a frog but isn't going to do anything to a human so these animals in no-way should be treated legislatively the same as a cobra. In the same regards, I would not be considering a varanid to be on par with a gila monster.

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Venomous monitors and bearded dragons, same as Rattlesnakes.

The original poster extracted this, so why wouldn't anyone else?

So what did you think of that little goanna? seen one before? FR

>>Venomous monitors and bearded dragons, same as Rattlesnakes.
>>
>> The original poster extracted this, so why wouldn't anyone else?
>>

That of course is independent of the research and beyond my control. Misinterpretation does not change biological reality.

>> So what did you think of that little goanna? seen one before? FR

Cute little bugger indeed. The biodiversity of the small monitors is indeed in need of much work.

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Bryan,

The report is fascinating; the work that you and your colleagues have conducted is truly groundbreaking. I devoured the report in its entirety yesterday. After seeing reports from the past of possible envenomations by Varanus species, I was a little skeptical, never seeing the proof; although, a very small V. salvator bit me once, caused a great deal of pain for being such a small bite and would not stop bleeding for 30 minutes. The evidence that you and your colleagues have assembled is quite compelling. Although some claim to have known all this already, no one has ever produced the proof.

Unfortunately, Frank is correct about the repercussions that this will produce in the US. Law in the US is too often based on ignorance because most lawmakers themselves are ignorant. They are more concerned about perceptions because to them perception is reality and they are experts at misinterpreting facts in order to promote their agenda. They care little about biological reality. Before moving out of the US, I learned that my old hometown had an ordinance prohibiting snakes over 6ft.; if a native 6ft. plus snake crawls around your home, you are breaking the law!

In your defense, your research is independent, like you stated. It is advancing knowledge and that is never a bad thing. If people twist your findings around and misrepresent them, making laws out of ignorance, that is not your fault; it is the fault of the ignorant. Anyone that knows about venomous reptiles should know who you are and what you do. You are doing important and groundbreaking work advancing the knowledge of venomous reptiles and other animals.

Thank you for your contribution to science,

Michael

Cheers for that mate.

Have to agree. The problem with new knowledge is what others interpret from it (depending on their level of knowledge in the area--or lack thereof).

In a country (USA) where Intelligent design is taken seriously by a huge portion of the population, it is easy for info like this to be turned against the herpetological community.

A pity.

Great paper though, and the photos are compelling.

Frank
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"The luxury of not getting involved departed with the last lifeboat Skipper..."

I think everyone is getting scared over some groundbreaking and very exciting information...dont scare off the scientists we need them in the hobby.
There are many animals sold in California legally today that pack a good bite, but are not deadly unless you have an adverse reaction just like a bee. Mostly spiders,scorpions and rear-fangs. So I would think a monitor that has no known deaths would create any concern.
P.S. How lucky are you guys to be in Oz!!! *click *click

Should name it the fat headed ackie cousin. lol

About the venom of some monitors, i would have to ask how fast is this venom working. What i mean is you say its a very small amount, enough to stun a small rodent. well a good size monitor will crush a small rodent so it seems useless to try to stun it as your crushin its head, doesnt it?? It just doesnt seem like they need it.

Hi mate

The yield is actually quite decent, e.g. 4 mgs for an ackie to up to 40-50 mgs for a good sized lacie. Easily enough to help dispatch a prey tiem. We're going to be having heaps of fun in the field over the next couple years completely reevaluating the prey capture strategies.

Cheers
B
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

I have often discribed a method of killing wild prey(with our captive lacies and perenty and others) that was odd, when we feed normal rats or mice, these larger montiors simply bite them and eat them, at times while still alive. I attribute this to the monitors knowing the prey is harmless.

But when I throw in a wild rat(neotona) or rabbit or squirrel. They do something different and odd. They pinch it with the front of their mouths and bite very hard. They are not crushing the prey, as they mainly have it by the skin, but you can see the jaw muscules working hard. The results are very odd, the prey simply dies, without being bitten lethally.

To make it interesting, the gouldi complex do not seem to understand this. when they attack large dangerous prey, they do not pinch it and wait until it dies, they commonly use other monitors to rip and tear the prey to pieces. And as you may know, the prey do not die all that fast. Until a lethal event occurs.

Once when Daniel Bennett was here, I showed him this group attack behavior. Its like many african predators, they circle, bit and let go, and come in from all directions until one has a limb and another an opposite part of the body, a third has another part and they then pull it apart.

To test this, we offered all sizes of prey, with prey they can easily swallow, an individual normally grabs swallows quickly or grabs and runs away from the other monitors. With large prey, they generally turn towards the other monitors.

Back to Lacies, when offered large dangerous prey items such as an adult wild rabbit. They "cover" it, like a bird of prey does when they wrap their wings around it. The falconers have a term for this, I forget for the moment.

With your new evidence, this now suggests if its not A or B, then its possibly C, as in something else. Just food for thought. FR

>> But when I throw in a wild rat(neotona) or rabbit or squirrel. They do something different and odd. They pinch it with the front of their mouths and bite very hard. They are not crushing the prey, as they mainly have it by the skin, but you can see the jaw muscules working hard. The results are very odd, the prey simply dies, without being bitten lethally.

Thank you for that. That is a truly fascinating observation.

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Australian Venom Research Unit,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
Population and Evolutionary Genetics Unit,
Museum Victoria
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

I believe the term is "mantling" (cloaking)

I was just rethinking this as i watched my ackie eat a frozen fuzzie that was a little to big. It took him a while to get it down and i believe if it was alive it would have been much more difficult, but if they had something to immoblize the prey that might make it much easier. Just a thought when i was watchin it tonight

adam

Treatments of betadine and bandaging, now with liquid bandage on it.
The teeth went through from the right side of the thumb then pierced upwards throught the thumbnail 1/4 inch in or more. 2 side by side actually, and 1 from the front of the thumb also.

Maybe I read it wrong or misunderstood where they were coming from but I didnt think they were saying Beardies were as venomous as rattlers, I took it that their venom/saliva (you pick) is the same substance as the venom found in rattlers but in lower quanities and there for being not harmful to humans. And in the case of the monitors (they said they used Lacies)they stated what affects it had on things but I didn't think they stated that it was the same compound as the beardy's or rattlers. Once again I may have read it wrong but thats the way I took it.