An Ethogram for Benthic Octopods (Cephalopoda: Octopodidae)

The present paper constructs a general ethogram for the actions of the flexible body as well as the skin displays of octopuses in the family Octopodidae. The actions of 6 sets of structures (mantle–funnel, arms, sucker–stalk, skin–web, head, and mouth) combine to produce behavioral units that involve positioning of parts leading to postures such as the flamboyant, movements of parts of the animal with relation to itself including head bob and grooming, and movements of the whole animal by both jetting in the water and crawling along the substrate. Muscular actions result in 4 key changes in skin display: (a) chromatophore expansion, (b) chromatophore contraction resulting in appearance of reflective colors such as iridophores and leucophores, (c) erection of papillae on the skin, and (d) overall postures of arms and mantle controlled by actions of the octopus muscular hydrostat. They produce appearances, including excellent camouflage, moving passing cloud and iridescent blue rings, with only a few known species-specific male visual sexual displays. Commonalities across the family suggest that, despite having flexible muscular hydrostat movement systems producing several behavioral units, simplicity of production may underlie the complexity of movement and appearance. This systematic framework allows researchers to take the next step in modeling how such diversity can be a combination of just a few variables