The platypus is one of the most biologically unique animals on Earth. With its duck-like bill, beaver-like tail, and otter-like feet, it puzzled European scientists upon its discovery. Platypuses are not poisonous; however, the males are one of the few venomous mammals.
The Difference Between Poisonous and Venomous
The distinction between poisonous and venomous organisms lies in the method of toxin delivery. Poisonous animals are harmful if you ingest or absorb their toxins. For instance, the poison dart frog carries a toxin on its skin, which is a passive defense; a predator must touch or eat the frog to be harmed.
Venomous creatures, on the other hand, actively inject their toxins into another organism. This is typically done through a bite, sting, or spur. A rattlesnake, for example, uses its fangs to inject venom directly into its target. Since the male platypus injects its toxin using a spur, it is correctly classified as a venomous animal.
The Male Platypus’s Venom Delivery System
The venom delivery system is a feature found exclusively in male platypuses. On the hind ankles of males are sharp, hollow spurs connected by a duct to the crural glands, which are kidney-shaped glands in the upper thigh that produce and store the venom. The spur can be moved, allowing the platypus to drive it into a target with force.
This system is linked to the mating season, when venom production significantly increases. This suggests its primary use is for males to compete with each other for mates.
While female platypuses are born with small, rudimentary spur buds, these structures do not develop. They are shed before the female reaches one year of age, and females lack the functional crural glands needed to produce venom.
Effects of Platypus Venom
The venom of a male platypus has a potent, though not typically deadly, effect on humans. Envenomation causes immediate and excruciating pain that case studies have shown to be resistant to conventional painkillers, including morphine. The pain can be severe enough to incapacitate a person and may develop into a long-lasting condition called hyperalgesia, which is a heightened sensitivity to pain that can persist for weeks or even months. Swelling develops rapidly around the wound and spreads.
While the venom is not considered lethal to humans, it can be fatal to smaller animals, such as dogs. There is currently no antivenom available for platypus envenomation. The complex mixture contains at least nineteen different peptides that affect blood pressure, blood flow, and pain receptors.