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Re: Toxicity Hemorrhois nummifer?

PostPosted: Tue Feb 01, 2011 2:06 pm
by Tomaz Jagar
Mario Schweiger wrote: I´m woundering, if effects only will occur, if the snake is chewing quite a long time?


That would make sense if we go with the theory that the saliva is mixed with toxic secretions and thus required to enter the blodstream via wound.

Re: Toxicity Hemorrhois nummifer?

PostPosted: Tue Aug 16, 2011 10:50 pm
by Philippe Wolf
Mario Schweiger wrote: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!



Hi,
do you have some literature about this subject on Thamnophis? Did they find specific teeth?

Re: Toxicity Hemorrhois nummifer?

PostPosted: Wed Aug 17, 2011 7:11 am
by Mario Schweiger
Philippe,

I have some hard copies of "venomous Thamnophis" - somewhere!
Beeing out of time at the moment, I will have a look for them on weekend, and will make PDFs of them.

Mario

Re: Toxicity Hemorrhois nummifer?

PostPosted: Wed Aug 17, 2011 8:51 am
by Philippe Wolf
Thanks a lot!
Waiting for your pdf
Cheers

Re: Toxicity Hemorrhois nummifer?

PostPosted: Sat Aug 20, 2011 10:16 am
by Mario Schweiger
I have scanned now the first one: PDF No. 2306 in literature database.

Vest, D.K. (1981): DARWIN K. VEST. The toxic Duvernoy's secretion of the wandering garter snake (Thamnophis elegans vagrans). Toxicon 19, 831-839, 1981.—The Duvernoy's secretion of the wandering garter snake (Thamnophis elegans vagrans) is highly toxic to mice, causing marked hemorrhaging in the lungs, diaphragm, mesentery and stomach lining, as well as mild local hemorrhaging. Systemic hemorrhaging was most pronounced in mice receiving doses approximating the p. LD50, while doses two times the LD50 or greater produced massive hermorrhaging in the lungs and diaphragm only. Local extravasations were directly proportional to dose. Oral secretions other than Duvernoy's secretion failed to produce lethal effects in mice challenged with doses up to 7 times the LD50 of Duvernoy's secretion. A micro-aspiration techniques for the collection of Duvernoy's secretion from colubrid snakes is described, and liquid as well as dried secretion yields for Thamnophis elegans vagrans are presented.

More will follow!
Mario

Re: Toxicity Hemorrhois nummifer?

PostPosted: Sat Aug 20, 2011 12:04 pm
by Mario Schweiger

Re: Toxicity Hemorrhois nummifer?

PostPosted: Sat Aug 20, 2011 11:52 pm
by Philippe Wolf
Thanks for sharing!
You gave me much more papers than I expected.
I saw few enlarged posterior teeth on the maxilla of my juvenile T. cyrtopsis, and according Kardong. 1979. this should not be fangs.
I'm stunned to learn that depending on the subspecies, some snakes (especially Diadophis punctatus) are or are not rear-fanged.
" Most subspecies of D. punctatus, with the apparent exception of the fangless D. p. edwardsii, are rear-fanged". Do you think they talk about real "fangs" with a venom apparatus from the Duvernoy's to the fang, or is it an improper use and it's just particular teeth? Are they Opisthodontus or Opisthoglyphous?

Cheers