Reptile & Amphibian Forums

I discovered recently the local museum has some false information on display and am looking to, politely, correct them. I've been searching for the papers that reported the presence of rear fangs and venom in colubrid species, specifically the genera Heterodon, Thamnophis and Nerodia. Could you please direct me should you know where I can find them? I've found a number of papers that mention Heterodon venom, usually in comparison, and I'm sure I can find similar papers that confirm it with the other genera, but if possible I'd love to cite source papers instead.

Also, as yet I'm a college student, though in another year I will hopefully be studying zoology in university. In the meantime, if I can find the information I'm looking for, I'm hoping I might convince the museum to let me correct their errors. But I really don't know how to go about calling their attention to it and convincing them I should be involved. Anyone have any recommendations?

thanks
Cheers
Kimbits

Dr. Bryan Fry's website is a good place to start. I posted the link below. Click on "Publications" to view his papers. Many of them deal with venomous colubrids, including the genera you mentioned.

It should be noted though that while Dr. Fry has presented evidence showing that many "non-venomous" colubrids actually possess venom (though many lack the dentition, i.e. rear-fangs), there is a clear distinction between "venomous" and "dangerous". Water snakes, garter snakes, and hognose snakes are not going to kill anybody, and in fact, most bites from those species are asymptomatic. I would strongly disagree with museums or zoos putting "Venomous!" stickers on their garter snake displays. In my humble opinion, all that will serve to do is confuse the lay person.

Snakes with enlarged rear-fangs and a venom apparatus however are fine to label as venomous...genera like Boiga, Hydrodynastes, Philodryas, etc. And of course Dispholidus, Thelatornis, and Rhabdophis, seeing as how they are dangerously venomous, with human fatalities recorded for all three genera.

Heterodon do possess enlarged rear-fangs, but I don't know how I'd feel about seeing a "Venomous" label on a hognose enclosure. One potential problem with zoos and such recognizing these species as venomous would be possible legislation being passed restricting possession of venomous snakes with trivial medical importance...can you imagine having to get a VRL for a hognose snake? Anyway...just my $0.02.

Sorry...here it is
Venomdoc

I'm aware that they're harmless, and I understand your point of view. I really rather hope that that's why they chose to display it as such. I've been tossing that idea around for awhile, but I have to wonder how many people would consider that? Us herp-lovers are atypical at best. I'm not about to recommend they put them in with the rattlesnakes (they're all stuffed specimens, btw) but why not educate about rear-fanged snakes? A lot of laypeople seem to know that a garter is venomous, and that it's harmless to people, and don't know which is true because they don't understand that they both can be in some cases.

At any rate, I'm familiar with Dr. Fry and venomdoc.com. and very impressed. I've read a number of his papers, and if I have to I'll use sources like that, that mention Heterodon venom comparitively with others, etc, but if possible I'd like to present them with a paper that is more direct than that.

Thanks for the reply

Kimbits

Since you're specifically asking about "rear-fanged" colubrids, I thought I'd jump in. Not all venomous colubrids have enlarged rear teeth or fangs. Coelognathus radiatus (formerly Elaphe radiata), the species of Asian ratsnake from which Dr. Fry obtained the homologue of an elapid venom component is an aglyphic (no extraordinary teeth) colubrid, rather than an opistoglyphic (rear-fang) colubrid. So let me say again, these 'colubrids' can be venomous, i.e. capable of producing venom from literal venom glands, without being rear-fanged. That being said, Heterodon is a venomous opistoglyph without a doubt. Thamnophis and Nerodia, however, are aglyphic. As for venom, I believe Thamnophis produces a real venom but I don't know about Nerodia.

I'll make the same point here psilocybe made: venomous doesn't necessarily equal dangerous. In fact, according to Dr. Fry, there are four factors that relate to how dangerous any venomous snake is: potency and complexity of venoms, quantity of venom produced, effectiveness of the delivery mechanism, and an effective antivenom being available (taken from venomdoc.com, under "Toxin Molecular Evolution).

So what is it you're wanting the museum to do exactly?
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Chance Duncan
www.rivervalleyexotics.com

I came across that the other day actually, aglyphic snakes, though I haven't looked into it as yet.

Though it's damned difficult to find, awhile back I came across a description of characteristics of the Thamnophis genus, it mentioned enlarged, posterior maxilliary teeth, which, though I could certainly be wrong, or the source for that matter, though they were citing something, sounds to me a lot like fangs. And sipedon, of Nerodia sipedon, refers, apparently, to the necrotic effects of its bite. lol, which is why I'm trying to find something a bit more concrete.

I'm looking to get some more, and varied, experience mostly. I think it'd be really interesting and I think I'd learn a lot, but I also, admittedly, really like the thought of how it would look on my resume. I've got another year of college before I'm applying to university and I'm hoping I can add a few interesting things to beef up my application.

Well, you certainly picked an interesting subject to look into! (IMHO) In fact, just recently we used Dr. Fry's work as a central focus of the biology seminar a group and I did at my university. As far as the world of venomous snakes goes, this area really presents one that's a hotbed of open, still undone work. It's implications to taxonomy and even future medical applications are enormous.

You might want to consider contacting Dr. Fry directly via e-mail if you haven't already and ask him about your interests. During the preparation for our seminar, he was extremely helpful to us in providing new sources and tidbits of information we were having trouble locating.

As for Nerodia, I can personally attest to their nasty bites! I've had a large N. rhombifer rip my finger nearly wide open and it seemed like it bled for days - okay, hours. I would be very curious to see if there was any actual venom at work, but so far I've only read about the 'anticoagulants' found in their saliva. Of course, those anticoagulants wouldn't be present in any normal saliva, so that could indicate an actual venom production. It wouldn't be terribly surprising considering their relatively close (I'm assuming here based on morphology) taxonomic standing with Rhabdophis. Same goes with Thamnophis. Fortunately they aren't as hot as Rhabdophis though, or I think we'd have a lot of dead herpers!

Anyway, good luck with your search. If you're interested, I can e-mail you the PowerPoint and/or notes we used in our seminar. Just contact me via this site or info@rivervalleyexotics.com and I'll send it/them over.
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Chance Duncan
www.rivervalleyexotics.com

Kimbits - I suggest that you contact the museum and ask to speak to the curator of the exhibits you noticed. Tell them you are a student, that you like snakes, and that you would like to talk to them about their exhibits. You can do this by letter, phone, or in person.

Speaking from experience, most (if not all) museums (and zoos!) are staffed by people who have knowlege and enthusiasim about the subjects at hand. Many of them are quite happy to have members of the public visit and even volunteer. You may find that the person responsible is aware of the interesting subject of venom and/or fangs in colubrids. He/she may be more than willing to work with you.

Long ago I spent a great deal of time at the Natural History Museum in Philadelphia getting to know the people behind the scenes. Away from the dry dusty exhibits, I got hands on with many fantastic herps including indigos, crocs, tegus, and huge snappers. I credit this experience with getting me well on the way to a life-long fascination with herps in general and snakes in particular.

Regards,

John D
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0.1 Creamsicle Cornsake "Yolanda"
1.0 Bairds Ratsnake "Steely Dan"

I have Dr Frys paper on rear fang venoms. it is very informative. Although I dont beleive it isolates hog nosed venom. Well worth the time to read though.
Kurt