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I fed a Texas patchnose (Salvadora grahamiae lineata) a lizard yesterday...and I swear he paralyzed it with his bite only! He latched on the lizard just above it's tail, no contriction was involved and he CHEWED on it for several minutes (reminded me of the way a coral snake "chews". Then he LET GO and slithered about a bit, then went back to the lizard WHICH WAS MOTIONLESS, NOT BREATHING AND APPEARED DEAD! He then ate it head first and the lizard did not move AT ALL. I was stunned! I have searched the web for any mention of patchnoses being rear-fanged, or having toxic saliva, etc. and came upon a site that said that ALL colubrids have some form of a Duvernoy's Gland! WHAT?!? I knew that hognose and some garters had this but ALL colubrids? Somebody in the know PLEASE give me a head's up on this because I am finding this hard to believe. Although that patchnosed experience was quite convincing!

>>I knew that hognose and some garters had this but ALL colubrids? Somebody in the know PLEASE give me a head's up on this because I am finding this hard to believe. Although that patchnosed experience was quite convincing!

It's not very often a scientist says this , but trust your own eyes on this one. The vast majority of colubrids (with some exceptions, such as the North American rat snake/corn snake/gopher snake/king snake group) do have venom glands, and it turns out that most actually produce some pretty potent venoms. Most are harmless to humans, but that does not mean that they don't have venom, it just means that they can't ordon't inject enough of it to do damage. Same situation as in spiders, they are all venomous, but most are harmless to humans.

Check out the papers by Bryan Fry, myself and others at the link below.

cheers,

WW
WW Publications

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Facinating stuff!!! So it would appear that most colubrids which are not constrictors have some degree of "super saliva" which could be considered a venom? But isn't that all venom really is anyway? Maybe it's a good thing the general public isn't aware of this. I can see it now: "better kill that green snake cause I heard them all gots a lil' poison in 'em!"
Thanks for that info!
~L

Hi mate

They are not only true venoms but the 'colubrid' venoms actually contain some of the exact same toxin types as found in elapid and viper venoms. For example, we purified the classic cobratoxin (the 'three finger toxin' type) from the radiated ratsnake. Same mode of action, comparable potency, etc. Cool

However, we stress that these snakes are venomous from a technical perspective but from a practical/legislative perspective the vast majority would be of no medical consequence what-so-ever (such as your patchnosed snake) and therefore should not be considered 'venomous' in the same way a cobra would. They can deliver enough venom to settle a prey item down (which is the entire point of venom of course) but not cause clinical symptoms in a human.

That said, many 'colubrid' venoms are just as potent as comparable elapid venoms. Boiga venom for example is just as potent as a death adders. It comes down to how much is delivered. The boomslangs/twig snakes are not the only dangerous ones out there. Some other groups of snakes should be considered as 'truly venomous', such as the Philodryas species as well as Psammophis, Rhamphiophis, and Malpolon or Rhabdophis. Boigas would fall into the 'warm' herping group. They are not likely to cause severe bites but can produce symptoms. Since these sorts of snakes don't have the advanced venom delivery architecture of a viper, they can mostly be worked with safely with just a long sleeve shirt and some gardening gloves.

All the best
Bryan
Colubrid neurotoxicity paper

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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

I was hoping an Australian would respond to my post! Thanks for your help on enlightening this dumb Texan!
Oh wait...you guys supported Bush too. JK
Thanks,
~L

>>Oh wait...you guys supported Bush too. JK

No we didn't. Our little twerp of a PM did. We have taken to calling him 'Bonsai' since he really just wants to be a little Bush.

Cheers
B
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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

>>>>Oh wait...you guys supported Bush too. JK
>>
>>No we didn't. Our little twerp of a PM did. We have taken to calling him 'Bonsai' since he really just wants to be a little Bush.

ROFLMAO!!! Now wouldn't that also be a perfect nickname for our wonderful (NOT) Tony Blair.... Private Eye magazine calls him the "Dear Leader" (Kim Jong Il's title in the North Korean press).

Cheers,

W
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