Meeting Abstract
Animals use a variety of behavioral and mechanical methods to access hard-shelled prey. Strategic application of force to fracture snail shells is observed in crushing and peeling predators, and these slow, high impulse strategies form the foundation of our current understanding of snail shell evolution. In contrast, mantis shrimp (Stomatopoda) impact and break snail shells with an ultrafast hammer. Here we test whether mantis shrimp select specific impact locations or randomly strike snail shells. We collected Neogonodactylus bredini and their size-matched molluscan prey (genus Cerithium) in Panama. Using video recordings of mantis shrimp feeding on snails, we noted the timing and location of every strike until the mantis shrimp began eating. The mantis shrimp followed a stereotyped behavioral sequence of rotating the snail, placing it on the substrate, tapping it with the antennules, often repeating these three behaviors, and then striking. Although individual mantis shrimp used a variety of strike location strategies, trends emerged across all individuals. Mantis shrimp rarely struck the body whorl and the middle third of the shell, yet frequently struck the apex and aperture. Mantis shrimp tended to strike near the aperture at the start of a trial and near the apex at the end. No sex or size differences were found in strike location, although larger mantis shrimp struck at a slower rate than smaller mantis shrimp. In conclusion, mantis shrimp follow a consistent pattern of strike locations when processing size-matched snails. Mantis shrimp impacts and behavior offer new windows into the role of fracture mechanics, force application, and behavioral strategies in the coevolution of snails and predators.
