Body patterns of Octopus vulgaris and maturation of the response to disturbance

Abstract

The list of visible features that supply the basis of body patterning in Octopus vulgaris is classified into chromatic, postural or movement components. (Their number is limited, variety in the expression of complete patterns being achieved by variation in intensity and spatial extent of components). Dark and light components are based upon chromatic units consistent with the patchwork structure of the skin. The pigmented and reflecting elements (chromatophores, iridocytes, leucophores) of these units express themselves in groups often with high tone contrast. A cryptic pattern, the flamboyant, appears in early settling stages as a generalized response to disturbance, both to a new environment and to the approach of threatening shapes (rubber bungs). In test observations on twelve animals divided into three body weight groups (<1 g, 1 to 5 g and 5 to 25 g) the flamboyant declines in incidence with increasing body size and is replaced by the dymantic as a specific response to threatening shapes.