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

BACKGROUND

Scorpions can use their pincers and/or stingers to subdue and immobilize their prey. A scorpion can thus choose between strategies involving force or venom, or both, depending on what is required to subdue its prey. Scorpions vary greatly in the size and strength of their pincers, and in the efficacy of their venom. Whether this variability is driven by their defensive or prey incapacitation functionis unknown. In this study, we test if scorpion species with different pincer morphologies and venom efficacies use these weapons differently during prey subjugation. To that end, we observed and sp. with large pincers and and sp. with slender pincers.

METHODS

The scorpion pinch force was measured, and behavioral experiments were performed with hard and soft prey ( and ). Stinger use, sting frequency and immobilization time were measured.

RESULTS

We found that scorpions with large pincers such as produce more force and use the stinger less, mostly subjugating prey by crushing them with the pincers. In and sp. we found they use their slender and relatively weak pincers for holding the prey, but seem to predominantly use the stinger to subjugate them. On the other hand, sp. uses both strategies although it has a high pinch force.

CONCLUSIONS

Our results show that scorpionspecies with massive pincers and high pinch force as use the stinger less for prey subjugation than scorpionspecies with slenderpincers.