Heavy metal scorpions

 

No, I'm blogging about the heavy metal band Scorpions! :)

Sam Campbell and co-workers have recently published an interesting study looking into how scorpions can harden their weapons. The scorpions main weapons are their powerful claws and their stinger (used to inject venom). The study hypothesizes that the scorpions are using metal enrichment in these structure to make them harder and stronger.

The study shows that metals like Zinc are used in strengthening the claws and the stinger, but not simultaneously. In species where Zinc was richly concentrated in the claws, it was scarce in the stinger, and vice versa. Scorpions with big claws usually crush prey and do not use the stinger, while species with more slender claws depend on the stinger and venom for subduing a prey. Interestingly, it was the latter groups where the metal content of the claws was highest. This has probably evolved as a compensation for the structural fragility of the scorpion withe slender claws.

An interesting study that both looks into the distribution and placing of the metals in the scorpion exoskeleton and discuss this in an evolutionary context.

Abstract:
Scorpions diverged from their closest relatives around the Ordovician Period, and since then, environmental interactions have shaped the evolution of the material properties of their exoskeletons. Hardening of this structure via the incorporation of transition metals has enabled biomechanical advancements in weapon development. Scorpion weapons consist of the stinger (telson) and claws (chelae) and contain diverse metals such as zinc, manganese and iron, though little is known about comparative patterns of incorporation across the wider clade. In this study, we harness X-ray-driven microanalytical techniques to characterize the different elemental enrichment patterns within the weapons of 18 species from a range of scorpion families. We hypothesized that enrichment by metal would be inversely correlated between weapons, tied to their functional roles and morphological diversity. We identified cryptic enrichment strategies, including weapon-selective elemental replacement and an inverse enrichment of Zn between weapons. Chela enrichment by Zn was found to positively correlate with a morphological indicator of chelae pinch strength, wherein Zn enrichment was greater in specimens with reduced crushing power. This study supports a growing body of research into the evolution of metal enrichment among invertebrates and provides a greater understanding of the material properties of the exoskeleton within weapon development.
 

Reference:
Campbell SI, Vicenzi EP, Lam T, Fry BG, Wood HM. Heavy metal predators: diverse elemental enrichment across the weapons of scorpions. J R Soc Interface. 2026;23(237). [Open Access]