This study examines interactions among diverse influences on octopus diet and behaviour.  Octopus cyanea were followed while foraging in July 2014 in Moorea, French Polynesia (17° 29’ S 149° 50’ W) and the results of foraging —revealed by prey species remains— were combined with data on habitat complexity, octopus density, foraging behavior and skin patterns.  The most common octopus behaviors were Exploring, Walking, Observing, and Stationary.  The proportion of time spent in different behaviors varied more between two foraging trips in the same habitat than among habitats, and thus the effect of substrate complexity was minimal on the tradeoff  between mobile and stationary foraging behaviors.  However body pattern use differed between habitats.  Dietary diversity was high (richness=64 taxa of Bivalvia, Crustacea, and Gastropoda, with low dominance) and positively correlated with octopus density at a site.  There was a non-significant trend in the relationship between the habitat substrate richness and diet species richness that suggests that on a local scale, habitat complexity influences biodiversity. Dietary diversity thus may result from overall prey community species richness and productivity, and in turn may influence octopus population density.