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

ABSTRACT

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°29ʹ S, 149°50ʹ 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that exhibited more approach behaviours during a disturbance test of personality, than for those that were more withdrawn.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.

KEYWORDS:

• Density
• diet choice
• habitat complexity
• midden
• personality
• prey size

Acknowledgements

We thank R. Anderson, and J. Poulpin for help with species identification; Sy Montgomery for her interest, enthusiasm and dedication, and two anonymous reviewers for their helpful comments. Financial support for this study was provided in part to JM as a Research Grant in Lieu of Salary through the University of Lethbridge, to DS through Alaska Pacific University from donations by the Pollock Conservation Consortium, and to TL through CNPq (National Council for Scientific and Technological Development) Support for Participation in Scientific Research Abroad (450912/2013.2). Findings and conclusions presented by the authors are their own and do not necessarily reflect the views or positions of the supporting organizations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the University of Lethbridge; Alaska Pacific University; the Pollock Conservation Consortium; CNPq (National Council for Scientific and Technological Development);National Council for Scientific and Technological Development [Research Abroad 450912/2013.2];