Is smashing always a success How a smashing mantis shrimp consumes both hard-shelled and soft-bodied prey


Meeting Abstract

49-2  Friday, Jan. 6 10:30 – 10:45  Is smashing always a success? How a smashing mantis shrimp consumes both hard-shelled and soft-bodied prey DEVRIES, MS*; RAZA, A; WEBB, SJ; TAYLOR, JRA; Scripps Institution of Oceanography, UC San Diego mdevries@ucsd.edu http://scrippsscholars.ucsd.edu/mdevries

Smashing mantis shrimp use their powerful, hammer-like raptorial appendages to break open hard-shelled prey, yet one species, Neogonodactylus bredini, also consumes soft-bodied, evasive prey. Given that the appendage is specialized for striking with great force, which is required for consuming hard-shelled but not soft-bodied prey, we hypothesized that N. bredini uses different feeding strategies to consume these distinct prey types. We compared the feeding behaviors that N. bredini individuals use to consume hard-shelled clams and evasive grass shrimp by analyzing real-time and high-speed videos of prey capture events. We found that mantis shrimp manipulated clams with their maxillipeds before striking the clams on average 21 times (17 s.d.) (1-55 strikes per individual, 55 individuals) with a mean duration of 0.8 ± 0.3 ms (1-6 strikes per individual, 17 individuals). Strike duration scaled positively with carapace length: R2 = 0.6, p <0.001). When consuming grass shrimp, N. bredini lunged forward and grabbed prey with their maxillipeds. Grab duration was 75.5 ± 34.0 ms (1-10 grabs per individual, 15 individuals), which did not scale with carapace length (R2 = 0.1, p = 0.1). Six individuals opened the dactyl segment of the appendage to impale grass shrimp during a strike. These strikes were longer in duration than those used to break clams (2.7 ± 2.1; 1-5 strikes per individual), likely because open dactyls increase drag. Overall, we found two distinct feeding behaviors used by N. bredini: appendage strikes and grabs with maxillipeds. Given that N. bredini is known to be a generalist predator, our findings suggest that individuals do not solely rely on their powerful smashing strikes, but instead have a repertoire of behaviors that aid in consuming a diversity of prey.

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