Reptile & Amphibian Forums

I can't find ANY information on these awesome creatures.

Are they common in the pet trade?
I know they are mildly venomous, are they "western hognose" venomous or are they dangerously venomous?

Are they easy to keep? I'm hoping that these snakes are not going to kill me or have me end up in the hospital because they would be amazing to keep.Also, are generally available at a good herp show?

Thanks.
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0.0.2 RES's (The Boondock Saints)
0.0.1 Common Snapping Turtle (Aggro)
0.0.1 Eastern Red Bellie (Jake)
0.0.1 Map Turtle (Mappy)
0.2.0 Bearded Dragon (Yeungling,Killian)

Are they common in the pet trade?
NO

I know they are mildly venomous, are they "western hognose" venomous or are they dangerously venomous?
Not considered a danger as they would have to chew and hold on long to use their rear fangs and their heads are too small, much less they are not aggressive.

Are they easy to keep?
Yes, but you need a steady supply of anoles to feed one anole every week. I think they perhaps also eat tree frogs but I have not offered them. And you must mist their cage to keep them hydrated.

I'm hoping that these snakes are not going to kill me or have me end up in the hospital because they would be amazing to keep.
If you die from one, you will be the first and the last.

Also, are generally available at a good herp show?
No. You should contact importers and request them. They arrive only a couple times a year and are quickly snatched up by reptile stores who resell them.

They require a tropical set-up and misting three times a week. Lots of branches and plants. And this little sucker in the pic has been in captivity for 5 years and coils in the palm of my hand but is about 4 foot long when stretched out. They stress easily from handling so if you wish to handle your pet snake, a blunt head is a not a good choice.

Dan

It seems you always have the strange and obscure animals; very cool!

I would not consider any snake with Duvernory's glands to be "venomous". There is a lot of controversy over this issue in the scientific literature but in my opinion a venom is injected to rapidly kill prey and is characterized by anterior hollow fangs and true venom glands. The functions of the toxic secretions that are delivered by enlarged posterior groved teeth do not serve as venom for the snake and I do not think they should be thought of as a venomous animal.

I think Dr. Bryan Fry has gone over this and if I understood correctly they do have an actual venom gland like many front fanged hots but it's their delivery system that is lacking. Is a legless lizard not a lizard because it doesn't walk as well as other lizards? Venom in different animals have different purposes. Rear fanged snakes use the venom to slow thier prey rather than kill, it's still venom, just a modified use. I think it is tremendously important to consider them as dangerous as normal hots. It would be irresponsible to sell an animal that can cause swelling, bleeding, oozing, and in some cases minor respiratory problems as a non venomous snake. The liability alone is not worth going there, and the idea that some kid who has a ball python can now handle an 8ft Mangrove is rediculous. They demand respect, period. Although they are not as dangerous as an elapid doesn't make them safe enough to consider non venomous. Just my two cents, Eric

It's kind of an apples and oranges thing. Cats are acceptable pets-yet people die of Cat scratch Fever. Dogs kill all too often. Horses kill too...yet no one bans them.

A rearfang snake is venomous yes, but the question is...are they dangerous? This has to be determined on a species by species level. Mangroves were sold for years as harmless and the chance of a serious envenomation even from a large one is small because they need to chew.

Bluntheads (I have kept them) are just not serious enough for the warning label.

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

Dr. Brian Fry is a medical Dr. not an evolutionary biologist. I am familiar with his work, but he is wrong. Fry just wants to make all snakes venomous so he can get $$ to fund his research. Look and Dr. Ken Kardong's work to get the evolutionary reasoning why there is a difference between a toxic oral secretion and a venom. Human saliva is toxic does that make us venomous animals?

I guess my point was that even though a serious envenomation from a Mangrove, or a FWC is unlikely, you do have the Boomslang, the Brown tree snake and others that have caused serious evenomations,(I know that that Brown Tree Snake chewed on some infants in Guam and got a bad name). I do agree that there should be some distinction between the two but at the same time you wouldn't want a kid walking into a pet store and buying a Mangrove I don't think. I free handle mine with no problem but I am aware that if it did get a hold of me I could have a minor reaction. Also people with sensativities to venom need to be aware that even a minor bite could cause anaphylaxis. I do see your point and I do understand what you were trying to say, I think it's important not to let the rear fangs fall into the harmless category all together. I live in Oregon, and it's illegal to own a Boiga Irregularis, or the Brown Tree Snake, but it is legal to own a Black and White Spitting Cobra. Maybe it's something in the water that has us all confused. Take care, Eric-

I am willing to bet that has more to do with them being an invasive species and not their relative danger.

>>Dr. Brian Fry is a medical Dr. not an evolutionary biologist. I am familiar with his work, but he is wrong. Fry just wants to make all snakes venomous so he can get $$ to fund his research. Look and Dr. Ken Kardong's work to get the evolutionary reasoning why there is a difference between a toxic oral secretion and a venom. Human saliva is toxic does that make us venomous animals?

Before you start accusing others of being wrong and, far worse, questioning their motives, you would do well to get your facts right. First of all Bryan Fry is a protein biochemist, not a medic. Second, being familiar with someone work is not the same as understanding it, and your comment about this being merely for $$ does not say much for your understanding of it. Any reason why you don't post comments like this under your real name?

If you want to argue that one snake's secretions from a particular structure, used to kill prey in 10 minutes, are venom, whereas the same homologous secretions from the same homologous structures that are used to slow a prey item down and perhaps kill it in a longer timespan are not venoms, then be my guest. I don't think you will have much company in the conceptual knot you are entangling yourself in.

Arguing that no snake with a Duvernoy's gland is venomous is probably not that smart - perhaps you should write to Dr. Karl P. Schmidt or Prof. Robert Mertens, and ask their opinions. Oh, sorry, you can't - they are dead, killed by what you would call non-venomous snakes.

Cheers,

WW
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WW Home

Wolfgang: You made several of the points I was going to make, but did a much better job of it. For that, I thank you.

~~Greg~~

Dangle....it! (Youse guys got there fursstus wit th' mostus said) (lol)

When your dealing with saliva too, it is not necessarily a venom as much as bacteria etc that are doing the damage bit....Read up on Komodo dragons.

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

Ok. First of all not everyone in the scientific community agrees with Fry. I do understand his work, so before you start questioning my competence you should do some of your own research on the opposing views. From a human perspective you could argue that these Duvernoy's secretions are a venom, but from the snakes point of view they do not serve as such. A boiga is a constrictor and very little of the Duvernory's secretions will penetrate beyond the preys skin. There has been a lot of research trying to identify the biological role of the Duvernory's secretions and the fact is we don't know what they are used for. There has been a plethora of hypothesized fuctions but nothing conclusive. And Fry is a medical Doctor, he works for the department of pharmacology in Australian venom research unit. I currently work on rattlesnake genetics at Washington State University and if you keep up on the scientific literature you can look for my work in the next year when I hopefully get published. My last name is Dobry, so I am using my real name.
Jason

As for the snakes being potentially dangerous I do agree that there should be precaution with owning such animals. I do not think that unexperienced keepers should own these animals.
Jason

>>Ok. First of all not everyone in the scientific community agrees with Fry.

That of course is entirely a persons right. If they have a contrary view, they can publish in a peer-reviewed journal and then citations will sort out which is accepted.

>I do understand his work, so before you start questioning my competence you should do some of your own research on the opposing views. From a human perspective you could argue that these Duvernoy's secretions are a venom, but from the snakes point of view they do not serve as such. A boiga is a constrictor and very little of the Duvernory's secretions will penetrate beyond the preys skin. There has been a lot of research trying to identify the biological role of the Duvernory's secretions and the fact is we don't know what they are used for.

Potent neurotoxins have one role and one role only, prey capture. The evolution of venom first followed by advanced delivery mechanisms to increase the efficiency of delivery makes perfect evolutionary sense. Many of the people arguing against this are very much *flat earthers* trying to protect a particular point of view that they have built their careers upon. I am simply trying to understand more about these fascinating animals and enjoy learning that they are even cooler than we thought they were.

> Fry is a medical Doctor,

Actually, I have an B.Sc. Honours degree in Molecular Biology (and another in scientific philosophy) and a Ph.D. in Biochemistry.

> he works for the department of pharmacology in Australian venom research unit.

I am not a pharmacologist, I am a molecular evolutionist. For historical reasons (the close research association between Struan Sutherland (the founder of the Australian Venom Research Unit) and Jim Angus (the former head of the Pharmacology Dept), the AVRU labs are located in the Pharmacology Dept but this is purely where our mail is delivered. Otherwise, we are complete autonomous. We are funded directly by the Federal government.

>I currently work on rattlesnake genetics at Washington State University

Good on ya.

> and if you keep up on the scientific literature you can look for my work in the next year when I hopefully get published.

We look forward to seeing your papers.

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

is how a scholar & a gentleman defends himself without using a flame-thrower. Good on ya, mate!

~~Greg~~

for attacking your motives. My question for you is this: if rear fanged snakes "venom" is in fact venom then why would such a inefficient delivery system persist? The boiga is a constricting snake, why then wouldn't an inefficient delivery system be selected out unless it has a different biological role? Your flat earther theory may have some truth, and although I attacked your motives I am glad you are doing the research that you are.
Jason

>>for attacking your motives.

No worries mate

>My question for you is this: if rear fanged snakes "venom" is in fact venom then why would such a inefficient delivery system persist?

Think of it this way, there are a myriad of available niches so a variety of combinations will naturally result.

A key aspect is that the relative delivery is only part of the equation. The colubrine snakes (as in the true Colubridae family e.g. Boiga, Coluber, Telescopus, Trimorphodon) for example feed typically on soft skinned, non-dangerous prey items such as frogs and geckos. Obviously not much in the way of dentition is needed to get through the skin.

Another key factor is which toxins are delivered. The colubrine snakes venoms are particularly rich in potent and fast acting neurotoxic 3FTx. A unique biochemical characteristic of this toxin type is that it is just as potent whether delivered just under the skin, deep into the muscle or even intravenously. This is in contrast to most other toxin types, which can have radical shifts in relative toxicity depending on the injection site (as a parenthetical aside, this is why LD50 charts can only be compared for a single method of testing, intravenous cannot be lumped in wiht subcutaneous for example, as was done in that dreadful snakes book put out but the Smithsonian). So, all the snakes have to do is get in a small amount of this rapidly acting extremely potent toxin type and their prey item is subdued. Even if the prey are only partially paralysed, they will rapidly suffocate once swallowed.

Constriction and venom aren't mutually exclusive. Some snakes may use it to help kill, others may use it to hold prey in place while envenomating. For example, the highly potent elapids such as the Australian brown snakes use constriction to hold prey items in place.

> why then wouldn't an inefficient delivery system be selected out unless it has a different biological role?

If it gets the job done for the niche the snake is occupying, then thats all that is needed. Predating upon more dangerous prey item wouldd increase the selection pressure for an improved armament whether having increased venom delivery efficency or producing more venom or independently adopt a powerful constricting condition and secondarily drop venom (such as the ratsnakes have done).

Cheers
Bryan

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

Thank you for you thoughtful clarification Dr. Fry.

At least twice in this thread, the statement is made that rearfang colubrids are constrictors.

Just for clarification for the peanut gallery, some do, but many rearfangs are not constrictors. For example Vine snakes like Oxebellus and Ahaetulla that just grab and chew. Others merely use coils to pin down their prey and do not properly constrict.

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

If you can get one, dont worry about it. As was already pointed out these snakes are not aggressive. They are calm when handled. I have caught several in Costa Rica and none even came close to acting like it might bite. If you have concerns just wear gloves.

I'm glad Dr. Fry was able to attend, and WW, great responses too.

I think that it's lost though that the definitions of venom, venomous, and dangerous are all different.

This is how I see it.

venom is a chemical compound, namely produced by some for the quick killing of prey, but this same compound may be found elsewhere in nature.

venomous describes an animal that produces venom and has some means of delivery.

dangerous goes hand in hand with venomous, but for all intents and purposes, can be used to describe those that can hurt/kill you.
Thus a snake can be described as venomous, or dangerously venomous. All just adjectives that better pass on a description.
ian