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Dear all,

The other day I had a minor discussion with some fellow field herpers about the presumed toxicity of Hemorrhois nummifer. I thought this species is venomous, they thought it isn’t. After scrutinizing my field guides and the internet I couldn’t find much about it, but most of the stuff I found stated that H. nummifer is harmless and/or non-venomous... I almost started doubting myself, until I came across a description of some bite incidents caused by the related Hemorrhois ravergieri. The symptoms seemed pretty nasty, maybe not life-threatening, but still… I think that H. nummifer is related closely enough to say that they are capable of inflicting the same kind of bites, but is there any evidence around supporting this?
If so, it might be good to know, since I sense that this is not really common knowledge, and obviously there are a lot of people in the field who don’t know or are not entirely sure about it (including me) and treat this species as a non-venomous snake (not including me)…

Hopefully some of you know more about this and want to share it?! And maybe not only about H. nummifer, but also about other “low profile” venomous snake species (e.g. Platyceps najadum).


Cheers! Maarten


PS Since the author of the aforementioned H. ravergieri description is the same person as the webmaster of this great forum, I thought I might post it here

This is a good question and it would be interesting to know!

..but also about other “low profile” venomous snake species (e.g. Platyceps najadum).

That also came as a surprise! I've never heard anything about P.najadum being venomous (even "low profile")! Maarten, where have you read this?

Benny has a nice picture about the najadum in his book about reptiles and amphibians of Greece.

I too have heard of bites attributed to Hemorrhois nummifer showing signs of envenomation, although I cannot confirm this firsthand.

I've been bitten twice by this species in southern Turkey - once on the wrist by a 70cm individual, and again the following year by a 1.3m snake between the first and second fingers of my right hand. Both bites were chewing and lasted for over 10 seconds, and each time there was no reaction observed apart from bleeding from puncture wounds, which did bleed for slightly longer than expected, perhaps 10 minutes or so. I would generally treat it as a non-venomous snake as I have never seen or heard about serious (e.g. hospitalisation or bad fever, oedema, etc...), although of course it can be an aggressive species which should be treated with respect as the large size combined with feisty nature are capable of inflicting painful injuries.

As for other aglyphous snakes, I cannot confirm any reactions experienced by myself like itching or swelling, but I have seen a photo of local swelling from the bite of a Hierophis viridiflavus.

Hello,

I wouldn't be surprised that bites from H. nummifer and other colubrids would cause some symptoms since more and more species are now recognised with (to some extent) toxic secretions from their Duvernoy glands. Such examples are N. natrix, N. tessellata and H. viridiflavus, but since they lack a specialised venom delivery sistem they are considered harmless.

I've been bitten numerous times by viridiflavus, but only once felt mild tingling in the bite area, which disappeared in a couple of hours.

Very interesting cases!

So H. nummifer could be harmless or you could be lucky, Daniel! Although the lack of symptoms doesn't give a decisive answer on the question whether this species is venomous or non-venomous, I still think that H. nummifer is thus closely related to H. ravergieri that it could be considered venomous as well.

The described symptoms caused by some Hierophis viridiflavus bites do sound like some kind of envenomation. Makes me wonder whether this is also the case for other Whip snake species... Btw, Ilian, I don’t know whether there are any scientific publications about venom in P. najadum, but I’ve read about this in Dieter Glandt's “Taschenlexicon”.

I think Tomaz is right with his remark that a growing number of Colubrids seem to possess some kind of toxic secretions. Even the snake I always considered one of the most harmless species, Natrix natrix, appears to have a very mild venom. Fortunately for this snake it has other, more effective defense mechanisms (which most of us probably know all to well)!

As it seems, there’s still enough to discover (fortunately ). A nice example: It wasn't until 2006 that they described venom toxins in Monitor Lizards and Iguania as well.

So be careful where you put your hands on...

Maarten Gilbert wrote:I don’t know whether there are any scientific publications about venom in P. najadum, but I’ve read about this in Dieter Glandt's “Taschenlexicon”.

As mentioned by Bobby, Glandt is also referring to the bite that Benny Trapp had.

I wonder if toxicity does not get mixed up with infection. In any case, there's the little story about Hemorrhois algirus that gave 3 of us mild symptoms on Malta (see report on my website), as you may already know.

Yeah, I was wondering the same thing. I guess it’s not always easy to discriminate between symptoms caused by envenomation and “normal” inflammatory responses, especially when the venom is weak. In the case of Hemorrhois, the symptoms do seem to indicate some level of envenomation. About the other European Whip snakes I’m not so sure... So the (presumed) toxicity of P. najadum is based on this one case only?? Or are there more?

I've been bitten numerous times be P.najadum, D.caspius and other (once by juvenile nummifer) and never had any symptom at all. I'm also wondering if some swellings caused by colubrids is a result of toxicity or microorganisms...
usually colubrid snakes that are supposed to cause symptoms are those which secret big amount of saliva.
On the other way I also never had a swelling by bees or wasps, so I don't know if I am a representative example.

I had local (little) "envenomation-effects", once by a large Hemorrhois ravergieri (see: http://vipersgarden.at/PDF/SchwMravergieri.pdf, sorry in German language) and by a large Dolichophis jugularis in S-Turkey too - although I´ve got bitten by Colubrids dozens (maybe more than hundred) times, when arranging the snakes to Ikebana 1) for pictures.
I´m woundering, if effects only will occur, if the snake is chewing quite a long time?
And remember, the list of "venomous" colubrids get longer from month to moth: Thamnophis, Heterodon; and before a few days I had a paper in hands, they found a venom gland (not Duvernoys) in Hierophis viridiflavus!

Mario

1) Ikebana: the Japanese art to arrange life flowers