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To continue a thread that claimed a shed Puff Adder fang could contain enough venom for a serious envenomation.

I took a shed Puff Adder fang from a specimen that was 15 to 20 inches long. See image below. This ~1mm fang could only hold ~ 9ul of water at 20 Deg C. Clearly not enough venom to require 8 vials of SAVP Polyvalent to counter-act.

As Prof. Wuster noted it could be dangerous if you get stuck with a shed fang from a hyper-toxic snake but not from a Puff Adder in this case. I think the main danger is allergic reaction to the the venom left in a shed fang.

Cheers,
Al

Previous thread

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Confidence is what you feel before you comprehend the situation.

Very impressive Al.
I trust you didn't use vise-grips to pull that fang! OUCH!
j/k!
Randal

I've seen my Puff Adder and Death Adder eject fangs during a strike that I recovered because I saw where it went. So, I thought it was a plausable that someone could be stuck by an un-seen fang.

Hmmm, interesting. I'm quite sure those projectiles are nothing other than daggers. Physics aside, I guess the next question at hand is the metric system. 100mm=1cm.
Mentors never cease to amaze.
Shane
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>>I took a shed Puff Adder fang from a specimen that was 15 to 20 inches long. See image below. This ~1mm fang could only hold ~ 9ul of water at 20 Deg C. Clearly not enough venom to require 8 vials of SAVP Polyvalent to counter-act.

Physics? Did someone say physics?

Actually, it's more like geometry this time. The person who reported the accident said his puff was "4 feet" which would make it up to 3 times the length of your specimen. Assuming for the moment that the fang size in proportional in all three dimentions (a big assumption) that would make it's internal volume 27 (3^3) times as much or about 540 ul (0.54 ml). While I've seen a lot of info about the minimum dose to cause death (at least in mice) I haven't seen much about the minimum dose to cause significant reaction, so I don't know how they compare. I will therefore claim ignorance as a conclusion...and no doubt many will agree.

Ahh I see that I made a typo...~10mm fang not 1mm.

This discussion is all based guestimates. I have something close to a 4ft long Puff but I'm not messing with her to get the answer to this questions. I think I will write the expert Mike at African Reptiles & Venom, who has milked more Puff Adders than anyone on the planet. Maybe he can provide some real numbers on wet & dry average yields.

Cheers!

Al

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Confidence is what you feel before you comprehend the situation.

>>To continue a thread that claimed a shed Puff Adder fang could contain enough venom for a serious envenomation.
>>
>>I took a shed Puff Adder fang from a specimen that was 15 to 20 inches long. See image below. This ~1mm fang could only hold ~ 9ul of water at 20 Deg C. Clearly not enough venom to require 8 vials of SAVP Polyvalent to counter-act.

Hi Al,

Glad to see you actually trying it out!

However, how exactly did you measure the quantity of water?

Not trying to be a pain, but looking at that fang next to the ruler, the average thickness of the entire fang is only ~1 mm. This means that the **external** volume of the fang (i.e., tooth material venom canal) is only 10-11 mm cubed, i.e., 10-11 ul.

Clearly, of that volume, a proportion is made up of tooth material, and another proportion is made up of the venom canal. I don't know what the relationship is, but looking again at Klauber's diagram, the diameter of the venom canal is approx. half the diameter of the fang, so the cross-section surface area of the venom duct is 1/4 of the entire fang cross-section surface - in other words, the canal makes up ~ 1/4 of the total external volume of the fang.

Therefore, if the total fang volume is 10 ul, then the volume of the venom canal should be ~ 2.5 ul.

That's why I am curious how you measured the 9ul - these very small quantities of fluid are not easy to measure! It would certainly be worth repeating themeasurements multiple times and get some sort of feeling what your error margins are like.

Cheers,

Wolfgang
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Hi Wolfgang:

I should have posted my methodology along with the results. My schedule has been hellish the past week, so I just posted the results.

I had the fang clamped in a pair of hemostats to give the fang a stable purchase while I was injecting water from my adjustable micropipetor from my lab at work. The pipetor tip was narrow enough to fit tightly into the duct end of the fang.

I started with 10ul of water to get a feel for the approximate quantity that was needed to see water appear at the exit of the fang without forming a drop. I used this as a staring point because of your inital caculation was for a 20mm fang and this was only 10mm. I "Blew" the water remaining inside the fang out between trials with gas from a "dust off" can.

After five subsquent tries with the pipettor set a 9ul I was satisfied that this was the volumn the fang could contain without designing an "insane" experiment where I weighed the fang dry and wet several times on the nano-balance in the chemistry department at work. I was trying to keep this simple and accuracy beyond this was not required.

Cheers!

Al
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Confidence is what you feel before you comprehend the situation.

Hmmm.... hard to fault the experimental procedure, but even so - the total volume of the fang is easily calculable (approx 10 ul is you assume an average diamater of 1 mm and a length (straightened) of 13 mm), and the volume of water that was used to fill it is almost the same as the volume of the fang. I have difficulty believing that only 10% of the actual volume of the fang is solid matter...

Drying it out, then weighing it on a superfine balance and then filling it with water and weighing it again may well be the best way, provided one can confidently get rid of ALL the water on the outer fang surface... Itdoesn't tanek much to throw thingsoff course when dealing with these very small quantities.

Another thing would be to try and split it open (or make a cross-section) to see the diameter of the venom canal relative to the entire fang.

Yeah, I know, we all have other things to do....
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If one has access to a micro CT machine, you could easily scan the fang and measure the volume of the inner canal...

-Michael Brodt
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Hi Wolfgang:

No worries Wolfgang, having read many of your papers I expected you to be a bit of a bugger for doing detailed experiments with precision. You're body of work on your website speaks to this careful approach.

I will try using our ug balance in the Chemisty lab as soon as I finish the conference I'm attending and return to my office. I also have access to a diamind wire saw, so the fang can also be cut down the middle along the length. I may also be able to gain access to a Micro-CT scanner as suggested. I bet one of the vendor at this conference will be selling them, so I will try to get them to run the fang before I saw it in two.

Cheers!

Al

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Confidence is what you feel before you comprehend the situation.

Nice work, Al - you might even get a small paper out of it

Cheers,

Wolfgang
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