Platypus venom
The platypus is one of the few living mammals to produce venom. The venom is made in venom glands that are connected to hollow spurs on their hind legs; it is primarily made during the mating season.[1] While the venom's effects are described as extremely painful, it is not lethal to humans. Many archaic mammal groups possess similar tarsal spurs, so it is thought that, rather than having developed this characteristic uniquely, the platypus simply inherited this characteristic from its antecedents. Rather than being a unique outlier, the platypus is the last demonstration of what was once a common mammalian characteristic, and it can be used as a model for non-therian mammals and their venom delivery and properties.[2]
Spur and crural gland
The venom is produced in the
Venom
The crural gland produces a venom secretion containing at least nineteen
The different chemicals in the venom have a range of effects from lowering blood pressure to causing pain and increasing blood flow around the wound.[4] Coagulating effects have been seen during experiments on laboratory animals, but this has not been observed consistently. Unlike snake venom, there appears to be no necrotising component in the platypus's venom. While some muscle wastage has been observed in cases of envenomation in humans, it is likely due to the inability to use the limb while the effects of the venom persist.[5] It is unknown whether the pain caused is a result of the associated edema around the wound or the venom has a component that acts directly on the pain receptors.
The platypus venom has a broadly similar range of effects and is known to consist of a similar selection of substances to reptilian venom, and appears to have a different function from those poisons produced by lower vertebrates. The effects are not life-threatening but nevertheless powerful enough to cause serious impairment to the victim, which can lead to temporary paralysis. It is not used as a method of disabling or killing prey, more as a defensive mechanism. Only males produce this venom. Since production rises during the breeding season, it is theorised that the venom is used as an offensive weapon to assert dominance and to control territory during this period.[4] While the platypus may use this characteristic for offensive mating purposes, they may have also adapted it for defensive techniques. Crocodiles, Tasmanian devils and raptors are known local predators to the platypus, all of which can be impacted by the venom.[10][11]
Effect on humans and other animals
Although powerful enough to paralyze smaller animals,
In 1991 Keith Payne, a former member of the Australian Army and recipient of the Victoria Cross (Australia's highest award for valour), was struck on the hand by a platypus spur while trying to rescue the stranded animal. He described the pain as worse than being struck by shrapnel. A month later he was still experiencing pain in that hand. In 2006, Payne reported discomfort and stiffness when carrying out some physical activities such as using a hammer.[14]
See also
References
- ^ PMID 18463304.
- ^ Jørn H. Hurum, Zhe-Xi Luo, and Zofia Kielan-Jaworowska, Were mammals originally venomous?, Acta Palaeontologica Polonica 51 (1), 2006: 1-11
- ^ Grant, J. R. "Fauna of Australia chap.16 vol.1b" (PDF). Australian Biological Resources Study (ABRS). Archived from the original (PDF) on 20 October 2013. Retrieved 13 December 2006.
- ^ a b c d Gerritsen, Vivienne Baillie (December 2002). "Platypus poison". Protein Spotlight (29). Retrieved 13 December 2006.
- ^ a b c "The venom of the platypus (Ornithorhynchus anatinus)". kingsnake.com. Archived from the original on 1 February 2012.
- PMID 7597719.
- PMID 18464734.
- PMID 12135762.
- PMID 18463304.)
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- PMID 9720107.)
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: CS1 maint: multiple names: authors list (link - S2CID 2452708. Archived from the original(PDF) on 7 March 2019.
- PMID 1454022. Retrieved 8 July 2023.
- ISBN 9780643093706.