One of the most fascinating and fearsome creatures in the world, the scorpion, is even cooler than you imagine. Research carried out today confirms that the weapons of these arachnids are literally covered in metal.
Scientists at the Smithsonian National Museum of Natural History and others closely studied more than a dozen species in the scorpion family tree. All scorpions had various types of metal in their pincers and stingers, although in unique, sometimes unexpected configurations. These metals play an important role in helping scorpions hunt and defend themselves, researchers say.
“This study highlights that metal enrichment has diversified strongly in relation to how different species have evolved to use their pincers and stingers,” lead author Sam Campbell, who was a predoctoral scholar at the Smithsonian at the time of completing the research, told Gizmodo.
metallic arachnids
Scorpions are part of the arachnid family, although they split off into their own branch about 435 million years ago. they are thought It was one of the first animals to jump from the sea to land, and it has been an exciting success story ever since. Much of this success is due to his body shape, which has remained remarkably consistent to this day. Its pincers and rapidly lashing tail, equipped with a stinger that releases powerful venom, can be used both to subdue prey and defend itself against potential threats.
Previous studies have shown that some species have metal in their pincers and tails. That said, according to the researchers, it was not known whether this is a universal characteristic or whether the composition and location of these metals could differ significantly throughout the great order of scorpions.
“To our knowledge, our study is the first to perform a statistical analysis of metal uptake in scorpions while also taking into account phylogenetic relationships,” the study’s lead author, Hannah Wood, a research entomologist and curator at the Smithsonian National Museum of Natural History, told Gizmodo. “This meant we could effectively map how metal enrichment varies between species and statistically test whether different metals were evolving together, taking into account shared ancestry.”
Thanks to the National Museum of Natural History’s extensive collection of preserved specimens, researchers were able to study 18 species representing different broad groups of scorpions. They used high-resolution electron microscopy and x-rays to closely examine the scorpions’ spiky appendages.
They found several similarities and differences between the different scorpions. Zinc was the most common metal found on the tips of scorpion stingers, for example, followed by a layer of manganese. Scorpion pincers tended to have zinc or a mixture of zinc and iron, although usually only on the edge; This suggests that these metals are essential to ensure the durability of these weapons when hunting prey. And the more zinc one scorpion had in its tail or claws, the less it had in the other, indicating an evolutionary trade-off, according to Campbell.
Surprisingly, the researchers found less zinc in species that had stronger crushing pincers, contrary to their expectations that zinc would be vital to increasing the strength of these weapons. “This means that scorpions with thin, weak claws have higher concentrations of zinc in the claws, which likely improves wear resistance and toughness when physical influence is lacking,” Campbell said.
Although scorpions may depend on them in different ways, they are probably all at least a little heavy metal, researchers say.
“Arguably that’s exactly what this study shows, although it’s important to note that we tested 18 species in this study,” Campbell said. “There are nearly 3,000 species of scorpions and they are all likely enriched in metals!”
The team’s findings were published Tuesday in the Journal of the Royal Society Interface.
What could come next?
Campbell worked on this project as part of his thesis. His main area of research now is venom, particularly scorpion venom. But there’s a lot more other researchers could learn about metals in scorpions and similar arthropods (the broad group of invertebrates that includes arachnids, insects, and other critters).
It would be nice to look for metals in an even wider variety of scorpion species, for example. Some researchers have also speculated that diet could influence how much metal a scorpion may have. And since female scorpions are typically much larger than males, they may also have a lot more metal.
The fangs of spiders, as well as the stingers of bees and wasps, are also known to contain metal. However, it is not clear whether these body parts have the same composition as those of scorpions or whether the infusion of metal into these natural weapons is an evolutionary trait inherited and widespread among arthropods, Campbell noted.
The team has created a method aimed at standardizing how scientists can measure metal in arthropod exoskeletons. With any luck, these and other questions could be answered in the near future.
In the meantime, I just hope this discovery inspires some game developers to create a big scorpion-themed boss to fight one day (for the nerds, yes, I’m already aware of the scorpion guard of Final Fantasy 7).
