Scorpions Reinforce Stingers, Pincers with Heavy Metals

Scientists have discovered that scorpions reinforce their stingers and pincers with specific heavy metals, tailoring the distributions to match their hunting and defense strategies. In a study of 18 species published April 28 in the Journal of the Royal Society Interface, researchers used high-resolution electron microscopy and X-ray analysis to map concentrations of zinc, iron and manganese in the arachnids' exoskeletons.

The analysis revealed distinct patterns. Stingers consistently featured zinc concentrated at the needle-like tip, followed by a layer rich in manganese farther down the structure. This gradient likely enhances piercing ability and venom delivery endurance. In pincers, particularly the movable tarsus segment, zinc or a combination of zinc and iron appeared along the inner cutting edges, bolstering areas subjected to crushing and gripping stresses.

A key finding showed an evolutionary trade-off: species with elevated zinc in pincers had lower levels in stingers, and vice versa. For instance, burrowing scorpions of the Opistophthalmus genus prioritize robust pincers for prey capture and digging, relegating the stinger to a secondary role. In contrast, Parabuthus...