"We believe that the dragon is able to weaken and immobilize their prey with a venomous bite that increases the damage done by their long serrated teeth," said Dr Fry.
The researchers located and surgically excised the glands from a terminally ill dragon at the Singapore Zoo, and used mass spectrometry to obtain a profile of the venom molecules. The team also analysed which toxin genes were expressed in the dragon's venom gland.
The effects of venom were also tested by the team and found to be similar to that of the gila monster and many snakes which cause a severe loss in blood pressure by widening blood vessels, thereby inducing shock in a victim. These findings may explain the observations by Dr Fry and others that Komodo Dragon prey become still and unusually quiet soon after being bitten. Bitten prey also bleed profusely, consistent with the team's discovery that the venom was also rich in toxins that prolong bleeding.
The researchers also examined fossils of the Dragon's giant extinct relative Megalania (Varanus priscus). From similarities in skull anatomy they determined that this seven metre lizard would have used a similar venom and bite system, making it the largest venomous animal to have ever lived.
|Contact: Nerissa Hannink|
University of Melbourne