...and he's got a secret weapon that James Bond would be proud of.
There's no question that the platypus (Ornithorhynchus anatinus) is one of the cooler animals on the planet. It's one of only five surviving species of egg-laying mammals (along with four species of echidnas), it has a tail like a beaver, and a beak like a duck (reflected in both its genus and species names). It is unique enough, and symbolic enough of its homeland, that it's featured on the Australian twenty cent piece. What is less well kn
own about the platypus is that it is also one of very few venomous mammals. Most of the others are shrews, or shrew-like solenodons, which produce venom in modified salivary glands and deliver it through their bite in the same way that venomous snakes do. The platypus is different, in that it has an ankle spur on its hind limb connected to crural gland which produces a pretty impressive witch's brew of proteins. The venom is capable of killing small animals - it's not lethal to humans but, by all accounts, will produce an experience not soon forgotten. The excruciating pain can persist as hyperalgesia that may last for weeks. Both males and females have spurs, but only males produce the venom - that makes it even more interesting from an evolutionary perspective. Throw in the fact that venom production increases in during the mating season and it seems likely that we're looking at an adaptation associated with a dominance heirarchy associated with reproduction.
In a study just published by the American Chemical Society, Misaki Kita and colleagues describe their analyses of the venom of the platypus. Employing a bioassay using nerve cells, they identified eleven novel peptides, with one called heptapeptide-1 playing a particularly significant role. Their studies suggested that the venom might act by affecting the influx of calcium ions in nerve cells. The venom is described as being "like hundreds of hornet stings." So, while he may look cute, step lightly. He's packin'.
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