Dominance and den use in octopus bimaculoides

Abstract

Past studies have indicated that dominance relationships based on size occur in octopuses. It is unclear, however, why this behaviour evolved since octopuses are solitary animals that do not form social aggregations. The hypothesis that dominance determines den use when dens are limited and vary in quality was tested using Octopus bimaculoides. The results from this study support this hypothesis. In a large circular tank, three octopuses competed for two dens that varied in quality and there was a significant association between den use and dominance rank. Wet weight and mantle length were highly correlated and both were good predictors of the dominance of an individual. The results also suggest that O. bimaculoides is able to recognize whether an individual is dominant or subordinate to it and that this recognition occurs quickly. Copyright © 1993 The Association for the Study of Animal Behaviour.