Pinching or stinging? Comparing prey capture among scorpions with contrasting morphologies

Area of Science:

• Zoology
• Ecology
• Animal Behavior

Background:

• Scorpions utilize pincers and stingers to capture prey, with varied strategies.
• Pincer size, strength, and venom efficacy differ significantly among scorpion species.
• The driving factors behind this weapon variability (defense vs. prey capture) remain unclear.

Purpose of the Study:

• To investigate if scorpion species with distinct pincer morphologies and venom potencies employ different prey subjugation tactics.
• To analyze the relationship between pincer characteristics, venom use, and prey immobilization strategies in selected scorpion species.

Main Methods:

• Measured pinch force in scorpions.
• Conducted behavioral experiments using hard and soft-bodied prey.
• Quantified stinger use, sting frequency, and prey immobilization time.

Main Results:

• Scorpions with large pincers (e.g., *Opisthacanthus elatus*) exhibit high pinch force and reduced stinger use, immobilizing prey primarily through crushing.
• Species with slender pincers (e.g., *Centruroides edwardsii*, *Tityus* sp.) use pincers for holding but predominantly rely on their stingers for prey subjugation.
• *Chactas* sp., despite having strong pincers, employs a mixed strategy involving both crushing and stinging.

Conclusions:

• Scorpion species with massive pincers and high pinch force use their stingers less for prey subjugation compared to species with slender pincers.
• Pincer morphology significantly influences the primary weapon system (pincers vs. stinger) employed in prey capture.