Reptile & Amphibian Forums

Photo: Bryan Fry collecting poisonous snakes in the Florida Everglades (B. Fry)

AUSTRALIAN BROADCASTING CORPORATION 22 August 03 Venom common, predates snake evolution (Danny Kingsley)
Venom is much more common among snakes than previously thought, and its origins predate the evolution of snakes, according to surprising new Australian research.
By personally catching and milking thousands of snakes around the world, Dr Bryan Fry from the Australian Venom Research Unit at the University of Melbourne has shown that even snakes that we think of as non-poisonous have a venomous bite.
His results were presented at the annual Fresh Science forum for young scientists being held as part of Australia's National Science Week.
Perhaps even more surprising, Fry has found that venoms have been evolving a lot longer that the snakes themselves. "Snake venom developed only one time in evolution, a few hundred million years ago," he said.
To test this theory, he analysed the 'saliva' of an archetypal 'non-venomous' snake, the ratsnake, to see how far back venom components started in the evolution of snakes. The ratsnake, which is commonly sold in pet stores around the world, contained the same toxins as a cobra or death adder, and the toxins were just as potent.
Researching snake venom is not without hazards. Fry has travelled the globe looking for representatives of the major snake lineages. In 2002, he milked over 2,000 snakes and was poisoned four times - including suffering a cobra bite. He even suffered an episode of the bends after diving for sea snakes in the remote South Pacific.
Fry was able to use the isolation of the snakes in Madagascar - which have been separated from all other snakes for between 40 to 150 million years - to compare the venoms with all the other major lineages across the world: the 'non-venomous' snakes, the elapids and the vipers. He was able to determine the toxins they all shared in common.
Snakes originally evolved from heavy-bodied swamp monsters, not dissimilar to modern anacondas, he said. To become lighter and more athletic, the snakes needed a new arsenal and developed venom. "This origin of venom is so far back, it occurred before the snake we commonly think of as 'non-venomous' even showed up on the tree of life," he said.
By tracing these against the evolutionary tree of snakes, he is able to present the venom of the very first venomous snake.
The implications of the study are far reaching: it show that the number of snakes containing venom is actually 2,700 - not the 250 previously catalogued as poisonous. And there is also the possibility of new drugs will come from the work.
One industry that will be affected by this finding is the pet snake trade, an industry that is highly regulated in Australia at least. In other, less regulated countries, there have been cases of people being bitten by pet snakes and falling ill.

Venom common, predates snake evolution

I think i would rather take a bite from a healthy 6 foot bull snake than a sick fangless mamba.Or maybe i just dont understand what Fry is getting at?...Paul>

I'd rather take a bite by a mamba than a good sized Philodryas, Psammophis, etc. or other rather toxic species for which no antivenom is available (see twig snake for another good example).

We are not taking the 'scare the crap out of the public angle' but rather an educational one. Should all these snakes be treated as dangerously venomous? No way. Should some of these snakes? Definately. Do we know which? Nope. Should all be banned? Of course not (have a look on the herplaw forum for my many efforts to actually keep venomous legal in many jurisdictions).

Stepping outside the legalise of all this, from an evolutionarly perspective, this is all extremely cool.

Cheers
BGF

------------------------------

Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
Department of Pharmacology
University of Melbourne

Ive read the article 5 times now and im seeing my hobby of keeping nonvenomous being illegal soon.Fry?Are you trying to get everything banned?I cant believe the non-friendly press isnt making something bigger out of this.If not now it will be soon.Fry did the media rearrange your wording?Im at a loss for words.Ive enjoyed reading your articles and watching your videos.Even though i cant keep venomous in Illinios, there trying to ban all reptiles in Chicago right now.It only takes a politician/alderman a slight hair up there a#$ to try to pass legislature banning reptiles alltogether.If i have missread the meaning in your article i humbly apologize....Paul.

Hi Paul

Have a read of the article a couple posts below and then get back to me. What we have discovered is that the various colubrid lineages are actually putting out the same toxins as cobras, etc. Does this mean all are dangerous? Certainly not. Does this mean that there are dangerous species lurking in there? Definately (see Rhabdophis for a good example).

I didn't cause the snakes to evolve this way, merely researched it. Would you rather I just buried the facts?

Cheers
BGF

------------------------------

Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
Department of Pharmacology
University of Melbourne

Mr.Fry im just saying that wasnt in the article that I read.That was a lopsided article on ABC.It's telling the general public all snakes are lethal or at least very dangerous to keep.I was brought up in an area where the only good snake is a dead snake and sadly enough that's true in alot of places.The general public needs educated on both sides of your study.They need to be reassured that Junior's garter snake isnt going to kill or maim him.Im a steelworker by trade but I always have time to talk and try to help remove fears of our local reptile population to the people at work and the people and children in my community.As far as your research goes your a man I admire and respect.Hell i envy you!The article was just slanted in the wrong direction and it will have a impact on the non-knowing snake haters of the world...Paul.

G'day mate

Here is the key phrase from my interviews, the one I keep repeating to the reporters in the hope that at least one will get the point

--------
“My research now shows that the vast majority of the snakes commonly kept as pets are actually venomous. Are all these species dangerous? Certainly not,” Bryan says.
‘Are there highly venomous species lurking in the petshops that we don’t know about? Definitely. I’ve consulted to two US petshops where employees were paralysed after being bitten snakes thought to be totally harmless.
----------

The ABC didn't stray too far from this and did say that people have been 'falling ill' from 'non-venomous' snakes, this of course can't be disputed. It didn't however, say all were dangerous and all should be banned. It would have been nice for them to clarify the point of relative danger but they certainly didn't take it to extremes and say all were going to be lethal

Yes this will all have an impact. This is why I have been dropping rather heavy hints for the last year (and even sending preprints to key people) so that the herpers had time to digest it and thus be prepared for potential a$$inine reactions from moronic politicians.

Have a look through some of the various posts in the past and you'll see I've gone through great lengths to establish the difference between 'technically venomous' (eg. the radiated ratsnake (C. radiatus) for example) and 'venomous from a practical perspective (e.g Psammophis mossambicus).

The difference is that the former is rather unlikely to do anything while the latter is almost certainly gauranteed to smack you hard.

Cheers
BGF
Venomdoc Homepage

I noticed that you mentioned them and I am really curious to just how dangerous a bite from them is. I have had a few and they remind me alot of thamnophis in habits and behavior, but took extra caution around them because I have heard so many stories both ways about them. I am curious to what type of reactions people who have been bitten have had.
Thanks
Kevin

>>I noticed that you mentioned them and I am really curious to just how dangerous a bite from them is. I have had a few and they remind me alot of thamnophis in habits and behavior, but took extra caution around them because I have heard so many stories both ways about them. I am curious to what type of reactions people who have been bitten have had.

Your post illustrates better than anything BGF or I could have written why this sort of information needs to get out there.

Rhabdophis tigrinus has killed people in Japan. Powerful prothrombin activator, if I remember correctly - causes lack of blood clotting and haemorrhages, as well as kidney damage. The closely related R. subminiatus was a popular pet shop snake in the 70s, until a number of serious, life-threatening envenomations to herpetoculturists in the US and Europe led to its true nature being recognised. The fact that nobody died is very much a matter of luck. A prolonged feeding bite to a kid might well have had different consequences.

In other words, your Thamnophis-like snakes were a dangerously venomous species.

What BGF and I are saying is Beware - there are very probably more colubrids like that out there, but we don't necessarily know which ones they are. For some, we have an idea (eg., Psammophis), for others, we don't.

Cheers,

Wolfgang
-----
WW

WW Home

"Your post illustrates better than anything BGF or I could have written why this sort of information needs to get out there"

Mr. WW the information on how dangerous Rhabdophis tigrinus and R. subminiatus is already out there. If someone wants to find out about them all they have to do is look for it. Some states in the U.S. already have laws agaist keeping Rhabdophis, Arizona is one of them.

Kevin Mr. WW forgot to tell you one very important thing about Rhabdophis tigrinus. What he forgot to tell you is that there is an Antivenom avaiable for treatment of bites by Rhabdophis tigrinus and R. subminiatus.("anti-yammakagashi" made by the Japan Snake Institute)

>>"Your post illustrates better than anything BGF or I could have written why this sort of information needs to get out there"
>>
>>Mr. WW the information on how dangerous Rhabdophis tigrinus and R. subminiatus is already out there. If someone wants to find out about them all they have to do is look for it. Some states in the U.S. already have laws agaist keeping Rhabdophis, Arizona is one of them.

It is available now, it was not back in the 70s and 80s.

The point is simply that there are almost certainly more Rhabdophis out there. We will almost certainly get a replay of the Rhabdophis episode with osme new species at some point. Some colubrids are already on the suspect list, others may not be - read the info on Telescopus in our paper. Some day, someone somewhere is going to get a very nasty shock from the bite of what was thought to be a harmless or at most mildly venomous snake. Publicising the new information may (a) help prevent it happening by encouraging keepers to be careful and sellers to give good advice, and (b) help alert medics that bites by colubrids previously thought harmless *may* occasionally cause more serious symptoms.

>> Kevin Mr. WW forgot to tell you one very important thing about Rhabdophis tigrinus. What he forgot to tell you is that there is an Antivenom avaiable for treatment of bites by Rhabdophis tigrinus and R. subminiatus.("anti-yammakagashi" made by the Japan Snake Institute)

So? The same is true for black mambas and WDBs. Would you like to see those sold to kids? Also, do you want to tell me how many vials of Rhabdophis a/v are currently stocked in the US? Scroll down a bit to the discussion of the B. nasicornis death to find out what can happen if antivenom is not readily (and I mean READILY) available.

Cheers,

Wolfgang
-----
WW

WW Home

G'day mate,

Yes, there is a Rhabdophis antivenom.... however, it is for domestic Japanese use only and is not exported. It took me months of cajoling just to get a single vial to test against other genera (such as Macrophisthodon).

In anycase, the thread wasn't about access to antivenom but rather non-front fanged snakes that are dangerous.

Cheers
BGF
Venomdoc Homepage

I treated them as deadly just in case and took all the precautions that I would with any other venomous snake. I was just curious to how venomous they really were. On another note, what are everyone's thoughts on false water cobras? I have heard stories that go both way with them also.
Thanks
Kevn

False water cobras have been banned in some juridisctions because they are as toxic as a rattlesnake. However the question 'so what?' should be the logical response.

Rattlesnake venom has a human lethal dose of about 100 mgs, obviously far more than a false water cobra will deliver (usually less than 10 mgs).

So, false water cobras are a good example of a snake that will not normally be able to do more than some impressive tissue damage from the powerful jaws and some moderate to decent localised swelling. However, they do contain low-levels of neurotoxins and neurotoxic effects have been reported.

By and large, I rate them quite low on the danger scale and as acceptable pets for teenagers as long as all the facts about the mild venom are given to the keeper.

That is all we are after, is an educational process. Some snakes (like radiated ratsnakes) can be safely kept by kids, others are more advanced (like the false water cobras) while others (such as Psammophis) should only be kept by someone with experience with venomous. Psammophis should actually be considered as advanced as a mamba. While they are less likely to kill you, unlike the mambas there is no antivenom. SO, if they get you badly you are screwed.

Cheers
BGF
Venomdoc Homepage

garter snakes are mildly venomous to some extent? I have heard this for many years, but have never had a serious reaction to them. I also heard(I forget where) that the toxins in their saliva is gradually getting more toxic? This is a very interested thread. You paper is also very interesting, should make people stop and think closely at how they view their favorite snakes. I feel it also shows that venomous snakes vary way more than most people ever think. I think when you say venomous, most people think elapids or pitvipers, your paper clearly shows that there are way more venomous creatures than most people think.
Thanks
Kevin

>garter snakes are mildly venomous to some extent?

Yep, same toxins. However, as we make crystal clear in the paper, the potential hazard posed by them is negligable. As for the venom getting more toxic, it is more a case of greater awareness rather than increased toxicity.

>You paper is also very interesting, should make people stop and
>think closely at how they view their favorite snakes. I feel it
>also shows that venomous snakes vary way more than most people
>ever think. I think when you say venomous, most people
>think elapids or pitvipers, your paper clearly shows that there are way more venomous creatures than most people think.

Give the man a prize, unlike our favorite fruitcake, you got the point entirely.

Cheers
BGF
Venomdoc Homepage

A lot of this goes back to the issue of education. I examined a 2' specimen of R.subminiatus back in 78 in a local petshop. It proceeded to chew vigerously on my wrist. At that time it was still listed in most available sources (including Laurouse)as a natrix. Since I was unfamiliar with this species of "Natrix" and I was involved with a wound near the tail I ignored it. By pure luck I did not get envenomated. What bothers me is that most the reptile dealers and petshops I run into don't have the foggiest idea of what they are selling except for the "NAME BRANDS". First, make sure your garter is a GARTER. Frank

>>A lot of this goes back to the issue of education. I examined a 2' specimen of R.subminiatus back in 78 in a local petshop. It proceeded to chew vigerously on my wrist. At that time it was still listed in most available sources (including Laurouse)as a natrix. Since I was unfamiliar with this species of "Natrix" and I was involved with a wound near the tail I ignored it. By pure luck I did not get envenomated. What bothers me is that most the reptile dealers and petshops I run into don't have the foggiest idea of what they are selling except for the "NAME BRANDS". First, make sure your garter is a GARTER. Frank

Thank you for that post - that is EXACTLY why we are pushing this new info out there. There are plenty more dangerous colubrids out there. Some are already on the suspect list, but others are not. The day one of them kills anyone after being sold as harmless will be a very bad day indeed for the entire herp hobby. Hence our exhortations not to take the harmless nature of most colubrids for granted.

Cheers,

Wolfgang
-----
WW

WW Home

That is why I am generally considered a pain in the ass down here. I have a bad habit of going into Pet shps and correcting ID's. It's not allways appreciated. Frank

>>That is why I am generally considered a pain in the ass down here. I have a bad habit of going into Pet shps and correcting ID's. It's not allways appreciated. Frank

LOL - It can be a good way of getting a discount, though!

"See that supposedly rare snake there? Actually, it's a dirt-common XXX - can I have it for $20?"

Cheers,

Wolfgang
-----
WW

WW Home

Sneaky................(Gotta try that)

On the subject of ID's: was I the only one at the expo who saw two Philodryas baroni offered up for sale in the nonvenomous show? They were at a young couple's (who spoke very poor English) table untill I explained what they were. They were then bagged and (I hope) removed. With what was going on next door...pretty ironic? Frank

There was an H. gigas bite some years ago at the Liverpool School of Tropical Medicine that hospitalized one of the researchers with severe local and systemic symptoms. The specimen in question was a really outrageously sized WC animal that had some time to chew. On the other hand there have certainly been numerous bites to hobbyists from other specimens with no symptoms at all.

We do know that venom may differ quite drastically between different populations of the same species of snake. Some species have been well enough studied that the venom variants are documented, eg Crotalus scutulatus, Crotalus horridus. I would guess that the same type of variability probably happens in any snake population that has a wide enough distribution to have evolved under slightly different local environmental conditions.

In short there may well be a particular locality of H. gigas (or any other snake) that can produce a more serious bite than one from a more commonly imported population.

Any input from Dr. Fry or Dr. Wuster on that leap of logic?

I was envenomated by H. gigas a few months ago. It was a c/b 2' male, on my right index finger. He got to chew a bit before he was removed. I experienced a rather interesting amount of local pain and minor swelling which lasted about a half hour, after which there were no further symptoms. Frank

There is every reason to expect that there will be geographic variation in the composition of colubrid venoms, and that it may have clinical implications. In fact, the paper showed some differences between two B. dendrophila subspecies.

Obviously, since Colubrid venoms are only now starting to be assessed at all, it will be a while before we know whetehr it is as common in colubrids as it is in vipers and elapids.

Cheers,

Wolfgang
-----
WW

WW Home

I noticed that you mentioned them and I am really curious to just how dangerous a bite from them is. I have had a few and they remind me alot of thamnophis in habits and behavior, but took extra caution around them because I have heard so many stories both ways about them. I am curious to what type of reactions people who have been bitten have had.
Thanks
Kevin

is what a lot of this is about.

The fact that most colubrids have venom glands (Duvernoy's glands) has long been known - we didn't discover that, it's all over the literature. What wasn't known until now is what's in them - we have now cracked that, and the results came as a surprise to us as much as to many of you.

The fact is, many, many "colubrids" secrete postsynaptic neurotoxins that are homologous with those of elapids, and that are in some cases just as potent. The reason, very simply, is that elapids and colubrids inherited this particular group of toxins, and many others, from the last common ancestor of all advanced snakes.

Does that mean they are all dangerous? Of course not, we *know* that many/most are not, from an extensive history of interaction with them.

What we are really dealing with is a need for education: we need to dissociate the word "venomous" from the concept of "dangerous".

Is Coelognathus radiatus venomous? Yes. Fact. No argument.

Is Coelognathus radiatus dangerous? No. Fact. No argument.

Snakehandlers in snake farms in Thailand and elsewhere in Asia get bitten by Coelognathus radiatus every day as a matter of routine often, it's part of the shows they put on for tourists), and there are plenty in captivity all over the place in Europe and the US, and their owners must get bitten with some frequency as well, considering what sweet-tempered snakes these are - NOT - and yet, has anyone ever heard of even the slightest symptoms? I certainly haven't.

Exactly the same applies to the considerable number of other "colubrids" with a long and intensive history of interaction with humans - garter snakes, a number of other Old and New World natricines (but of course Rhabdophis is dangerous), even hognose snakes. Venomous, yes, dangerous (at least life-threateningly so), no.

On the other hand, what our results should also do is to urge caution all round when dealing with some of the less-well known colubrids or rear-fangs of unknown potential. Now that we know that they are likely to have cobra-like neurotoxins in their glands, perhaps everyone will be just that little bit more careful with such snakes, and avoid making legislation-inducing headlines in the future. Don't be the one to discover the next Rhabdophis subminiatus!

As far as regulation is concerned, Coelognathus radiatus is no more dangerous now than it was 4 weeks ago - there is no more basis to regulate it than there was before.

As scientists, our job is to explore the world that surrounds us, and to provide the facts. This BGF and I have done in this case, and it is turning out to be a most interesting story. However, we cannot be responsible for the interpretation some copulationwitted legislator somewhere on the globe will draw from our data, and neither are we willing to see important and interesting scientific discoveries suppressed or hushed up for fear of misrepresentation.

We would be more than happy to be consulted over legislative matters, and to defend the legality of keeping most colubrids unhindered by any safety or public health-related legislation, but don't expect us to hide research results.

Cheers,

Wolfgang
-----
WW

WW Home

On the button in general, and especially the last two paragraphs.
Bill Huseth
kcf

overpressurization caused by the combined effects of my own ignorance and my perceived ramifications of this study...

In laymans terms, venom development predates delivery method development. In the absense of this new info I would have thought it to be the other way around. Selective development of toxins that are effective incidentally injected. Or perhaps parallel development. What the study demonstrates is that the similarity of toxins regardless of delivery mechanism provide a thread back to ancestral commonality. Evolutionary splits later on resulted in different delivery and storage methods for subtantially the same substance, putting those animals having "Duvernoys glands" a little behind (in evolutionary terms) those having developed effective delivery mechanisms.

My head hurts...

Maybe I'd be better off starting with the "Reptiles" article. When's that coming out?

Regards,
Jeff Nichols