Posted by:
paalexan
at Fri Aug 22 11:04:12 2003 [ Email Message ] [ Show All Posts by paalexan ]
`They use it for prey capture. Contrast the behaviour of the Asian 'Elaphe-types' with that of the Americans (which have recently undergone a secondary loss of the gland). The Asians are actually pretty pathetic contrictors but absolutely bite the living crap out of the prey item (quite viciously). The Americans do little biting (other than the intial strike) but are robust constrictors.'
Really? That's nifty... I guess I just don't have enough experience with Asian `Elaphe'. I've been keeping a Coelognathus radiatus for a few years, and he'll just do the typical Pantherophis thing... just one initial strike and a bunch of (apparently quite effective) coils.
Also, though, I remember seeing a paper a while back indicating that constriction rather than venom was the cause of prey death in Boiga irregularis...
`The evolutionary key here is that there was no evolutionary selection pressure for the development of fangs unless there was already a potent venom to deliver. Sort of like all primate lineages being able to make noises but we are the only lineage with the highly developed piece of architecture called the voice box.
Venom in the advanced snakes are analagous. The heavy bodied primitive snakes dumped the muscle that was essential for prey capture in order to become more gracile and agile. They needed a new weapon. Enter venom.'
Makes sense.
Patrick Alexander
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RE: Yup, they sure ain't Elaphe... more - paalexan, Fri Aug 22 11:04:12 2003