Diversity in the diet of the predator Octopus cyanea in the coral reef system of Moorea, French Polynesia

This study examines interactions among behavioural and environmental influences on individual octopus diet. Octopus cyanea were surveyed in July 2014 in Moorea, French Polynesia (17 degrees 29' S, 149 degrees 50' W) and the diversity of their diets - revealed by prey species remains - were combined with data on octopus personality, habitat complexity, prey size and octopus density to test hypotheses on three different levels: individuals, study sites and population. Diets were more diverse for octopuses that exhibited more approach behaviours during a disturbance test of personality, than for those that were more withdrawn. Octopus diets were more diverse within areas of greater substrate type diversity, suggesting that on a local scale, substrate type diversity influences biodiversity. Octopus diets were also more diverse when prey were smaller and where octopuses were more abundant, suggesting an effect of prey abundance (or conversely of competition among octopuses). For the Moorea population overall, dietary diversity was high (richness = 64 taxa of Bivalvia, Crustacea, and Gastropoda), with low dominance. This study confirms that to better understand the variation in octopus diet we should look from the individuals to populations, taking into account environmental and behavioural factors, such as individual personality, habitat diversity, prey sizes (energy) and octopus abundance.