DOI: 10.5061/dryad.2v6wwq02w
title: Data from: Structural and mechanical properties facilitate shock wave damping by helmet-like orbital hoods in snapping shrimp

description: Snapping shrimp damp the shock waves they produce and use as weapons with
 a helmet-like structure termed the orbital hood. Here, we ask how
 structural and material properties contribute to shock wave damping by
 orbital hoods in Alpheus heterochaelis. Using tensile mechanical testing,
 we find orbital hoods are approximately half as stiff as the carapace and
 have twice the capacity for viscous energy dissipation. Microstructural
 features likely contribute to tissue-specific mechanical properties: the
 endocuticles of orbital hoods have almost twice as many lamellae as those
 of carapaces, despite being half as thick, suggesting a mechanism for
 enhanced material mobility underlying viscous behavior. Using material
 properties from mechanical testing and geometric data from microCT, we
 developed finite element simulations of interactions between shock waves
 and orbital hoods. These simulations predict orbital hoods reduce shock
 wave-induced strain and stress in the neural tissues of shrimp by 28% and
 22%, respectively. Orbital hoods appear optimized for shock wave damping:
 simulated increases or decreases in their material properties reduce their
 protective capabilities. We conclude that structural and viscoelastic
 properties contribute to shock wave damping by orbital hoods, a promising
 step towards bio-inspired improvements to contemporary armor systems that
 currently underperform in preventing blast-induced neurotrauma in humans.
description: # Data from: Structural and mechanical properties facilitate shock wave
 damping by helmet-like orbital hoods in snapping shrimp Dataset DOI:
 [10.5061/dryad.2v6wwq02w](https://doi.org/10.5061/dryad.2v6wwq02w) ##
 Description of the data and file structure The orbital hoods of snapping
 shrimp are the first biological armor system shown to protect an animal
 from blast-induced neurotrauma by damping shock waves, a discovery that
 prompts questions about their mechanism of function. Here, we ask how the
 structural and material properties of orbital hoods contribute to shock
 wave damping in *A. heterochaelis*. ### Files and variables #### File:
 SLS_optimize_fixedTau_fun.m **Description:** MATLAB code for fitting the
 linear elastic model to the experimental data we collected for snapping
 shrimp exoskeleton samples #### File: viscoelastic_fitting_submission.m
 **Description:** MATLAB code for fitting the linear elastic model to the
 experimental data we collected for snapping shrimp exoskeleton samples
 #### File: TEM_Data_for_Kazel_et_al.xlsx **Description:** Measurements
 from TEM images of sectioned samples of snapping shrimp orbital hoods and
 carapaces (Epicuticle width, Exocuticle width, Endocuticle width, Total
 width, and Lamellae) with their respective average measurement. All values
 for widths are in microns. Specimens are labeled numerically (1, 2, 3,
 etc). Separate samples from the same individual are labeled by letter.
 Values for lamellae are counts. The epicuticle in the Hood tends to be
 thicker than in the Carapace, with a large effect size, but the difference
 does not reach statistical significance (p = 0.095) due to small sample
 size. ## Code/software The code included here is for MATLAB R2022b
 (MathWorks Inc., Natick, MA) ## Access information Other publicly
 accessible locations of the data: * All other relevant data can be found
 within the article. * For finite element analysis, we used LS-DYNA
 software, which is available here:
 [https://lsdyna.ansys.com/](https://lsdyna.ansys.com/) Data was derived
 from the following sources: * The Data included here is from TEM images of
 sectioned exoskeleton samples from snapping shrimp.