Meeting Abstract

P1-2   -   Extreme arm flexibility enables complex behaviors by octopus in tropical habitats Grossman, J/H*; Buresch, K/C; Bennice, C/O; Hanlon, R/T; California State University, Monterey Bay; Marine Biological Laboratory ; Florida Atlantic University ; Marine Biological Laboratory jegrossman@csumb.edu

Characterizing the form and function of arm flexibility in octopus is of keen interest to researchers in biomechanics, neuroscience and soft robotics. The arm actions used to achieve such flexibility have yet to be studied comprehensively in freely-moving octopuses in varied natural habitats. This study quantifies arm flexibility in naturally behaving octopuses by visually characterizing the arm actions that constitute a majority of octopus behaviors. Twelve arm actions were defined using field videos of naturally foraging Octopus vulgaris from the western Atlantic and Caribbean regions. More than 3,900 incidences of arm actions were observed from six field sites. All eight arms were found capable of executing each of the 12 arm actions along their lengths. Remarkably, individual arms frequently used more than one action at the same time and multiple arms performed several actions simultaneously. Anterior arms performed more arm actions than posterior arms, but there were no differences between left and right arm pairs. Analysis of discrete arm actions and their coordination provides baseline data of the dexterity, strength, sensing and control of octopus arms. The combinations of eight arms implementing 12 arm actions that enable 15 complex behaviors illustrates the extreme flexibility of these appendages and their wide range of functions.