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Hello snakelovers.
I was just wondering how venomous colubrids with no enlarged rearfangs deliver their venom?
And also regarding colubrids with enlarged rearfangs, where does the venom come out? Is it like a salivery gland or what?
Thanks a lot
Jonas Norit

as bgf says all non-constricting colubrids have venom and a true venom gland i.e the same as an elapid or viperid, most colubrids in which people assume have no enlarged rear fangs actualy have them

>>Hello snakelovers.
>>I was just wondering how venomous colubrids with no enlarged rearfangs deliver their venom?
>>And also regarding colubrids with enlarged rearfangs, where does the venom come out? Is it like a salivery gland or what?
>>Thanks a lot
>>Jonas Norit

All the colubrids have a venom gland sitting directly above the back teeth, which are typically enlarged to one degree or another. For snakes that feed on soft skinned prey like frogs and geckos, they don't need impressive armament to break the skin. Most of the very gracile snakes (e.g. Coelognaths, Coluber, Dendrelaphis, Telescopus, Trimorphodon, etc.) have venom that is loaded with potently neurotoxic 3FTx (three finger toxins). A unique biochemical nuance of this toxin type is that, unlike most other toxin types which are more potent the deeper they are delivered, 3FTx are just as potent whether straight into a vein or just under the skin. So, long rear fangs aren't actually a necessity. All they have to do is get it in. 3FTx are not only one of the most potent toxin types, but also one of the most rapidly acting. So, not much is needed and it doesn't take long. For non-dangerous prey items like geckos and frogs, all the snake really had to do is stun the prey and swallow it. While its paralysed in the stomach, it can get stuffed and suffocate for all the snake cares

The venom gland is the exact same one as in an atractaspid, elapid or viperid. The various 'colubrid' families all have different unique derivations of the same ancestral gland.

The exceptions are the ratsnake types which have independently adopted a constricting mode of prey capture in order to feed on more dangerous rodent prey items. A mode of prey capture more energetically suited to the temperate climates they occupy. Subsequent to this they have undergone a secondary loss of venom. Loss or degeneration venom is not without precedent, occuring at least three times in the elapids for example (two types of sea snakes that feed solely on fish eggs as well as in the lizard egg eating Brachyurophis genus).

Cheers
Bryan
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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