Scorpions Reinforce Their Pincers and Stingers with Metals

Researchers examined the dual front pincers (chelae) and the venom-injecting telson of 18 scorpion taxa from the Smithsonian National Museum of Natural History. High-resolution scans revealed zinc concentrated at the extreme tip of the aculeus and manganese dominating the region just below. Iron was also present in the examined specimens. The pattern was consistent across specimens, leading the authors to conclude that metal enrichment is a purposeful biological feature rather than incidental uptake.

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The presence of metals in scorpion appendages has been documented since the 1990s, but their evolutionary role remained unclear. Earlier work identified metal traces without determining whether they resulted from adaptation or environmental exposure. The new study addresses this gap by systematically comparing multiple species and mapping metal distribution at high resolution.

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The investigation was led by Sam Campbell, a biologist at the University of Queensland, Australia, in collaboration with Smithsonian researchers. Eighteen scorpion species representing diverse taxonomic groups were selected from the museum’s collection. Results were published in the *Journal of the Royal Society Interface*.

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High-resolution scanning electron microscopy (SEM) combined with micro-X-ray fluorescence (µXRF) imaging produced color-coded maps of metal distribution in each weapon. These maps allowed precise localization of zinc, manganese and iron within the pincers and stingers, supporting quantitative comparisons across the sampled taxa. These techniques captured metal distribution at a level of detail that resolved individual appendage regions.

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Zinc’s concentration at the aculeus tip is interpreted as a structural adaptation that enhances hardness and preserves tip strength. Manganese dominates the region immediately below the zinc tip, but the study does not specify its functional implications.

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Campbell noted that metal presence has been known for decades, yet systematic mapping shows intentional biological incorporation. He emphasized zinc’s role in maintaining tip hardness.

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The source material does not present any dissenting viewpoints or critiques.

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The sources contain no contradictory data and do not identify gaps regarding metal composition or functional significance.

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• “That the metals are there has been known since the 1990s,” — Sam Campbell, Biologist, University of Queensland

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• “What we didn’t know was whether scorpions evolved to be like that or if it was accidental and they were just picking the metals up from the environment.” — Sam Campbell, Biologist, University of Queensland

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• “Zinc has all to do with hardness and ensuring that we retain the strength of the tip of the stinger,” — Sam Campbell, Biologist, University of Queensland

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• “Based on their data, detailed in a recent study published in the Journal of The Royal Society Interface, there was nothing accidental about it.” — Sam Campbell and colleagues, Researchers

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