Meeting Abstract

P1.149  Monday, Jan. 4  Probing the evolutionary biomechanics of elastic energy storage in mantis shrimp ROSARIO, M. V.*; TAYLOR, J. R. A.; PATEK, S. N.; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of Massachusetts, Amherst

Structural and biomechanical variation in elastic energy storage mechanisms is fundamental to the rich evolutionary diversity of fast movements. Mantis shrimp (Crustacea: Stomatopoda) power their fast and powerful predatory appendages with an exoskeletal compressive spring. Here we compare the mineralization patterns of the spring and elastic energy storage mechanics across 10 species of mantis shrimp, including species with hammer-like, spear-like and intermediate raptorial appendage forms. Using computed tomography to visualize mineralization patterns, we found that the primary spring is conserved across all species, but its size, length and articulations vary considerably. A materials testing machine was used to measure the maximum compression force of the spring and the spring constant. We found that spring constants were nearly overlapping across species, even with a 200-fold range in body mass; however, body size scaling relationships varied across taxa. For example, three taxa exhibited no correlation between spring mechanics and body size while Gonodactylaceus falcatus exhibited a significant positive correlation between body size and maximum compression force and a non-significant association with spring constant, and Gonodactylus chiragra showed no correlation between body size and maximum force and a significant negative correlation with spring constant. This variation in spring form and mechanical behavior suggests that different prey capture strategies may indeed be associated with evolutionary variation in the underlying power-amplifying springs.