Data from: Smashing mantis shrimp strategically impact shells

Many predators fracture strong mollusk shells, requiring specialized
weaponry and behaviors. The current shell fracture paradigm is based on
jaw- and claw-based predators that slowly apply forces (high impulse, low
peak force). However, predators also strike shells with transient intense
impacts (low impulse, high peak force). Toward the goal of incorporating
impact fracture strategies into the prevailing paradigm, we measured how
mantis shrimp (Neogonodactylus bredini) impact snail shells, tested
whether they strike shells in different locations depending on prey shape
(Nerita spp., Cenchritis muricatus, Cerithium spp.), and deployed a
physical model (Ninjabot) to test the effectiveness of strike locations.
We found that, contrary to their formidable reputation, mantis shrimp
struck shells tens to hundreds of times while targeting distinct shell
locations. They consistently struck the aperture of globular shells and
changed from aperture to apex of high-spired shells. Ninjabot tests
revealed that mantis shrimp avoid strike locations that cause little
damage and that reaching the threshold for eating soft tissue is
increasingly difficult as fracture progresses. Their ballistic strategy
requires feed-forward control, relying on extensive pre-strike setup,
unlike jaw- and claw-based strategies that can use real-time neural
feedback when crushing. However, alongside this pre-processing cost to
impact fracture comes the ability to circumvent gape limits and thus
process larger prey. In sum, mantis shrimp target specific shell regions,
alter their strategy depending on shell shape, and present a model system
for studying the physics and materials of impact fracture in the context
of the rich evolutionary history of predator-prey interactions.