The coleoid cephalopods (octopus, cuttlefish and squid) are a highly advanced group of voracious marine predators endowed with a remarkable visual system. Most species spear to be monochromatic, however they possess orthogonally-arranged microvilli on their photoreceptors, providing sensitivity to polarized light. Retinal specialisations, such as horizontal bands, have been identified in several species, possibly providing higher levels of visual acuity and sensitivity to corresponding areas in their visual field. Coleoids possess a stunning repertoire of body patterns due to highly pigmented and changeable skin, which are used primarily for communication and camouflage. This study aims to conduct a comparative analysis of the visual ecology of coleoid cephalopods, comparing visual characteristics with both habitat and ecological niche. This will reveal whether environmental or phylogenetic pressures are primarily driving the evolution of their visual system. Functional polarization sensitivity will be demonstrated using an optomotor/optokinetic apparatus. Polarizing skin patterns will be analysed using polarimetry and spectrometry. Retinal structure and photoreceptor dimensions will be analysed to identify areas of specialisation and calculate sensitivity.

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