Social tolerance in Octopus laqueus - a maximal entropy model

Abstract

Octopus laqueus is a small tropical octopus found in Okinawa, Japan and the greater Indo-Pacific. Octopus are often viewed as solitary animals but O. laqueus live in close proximity in the wild, and will potentially encounter one another on a regular basis, raising the possibility of sociality in the species. To test for social tolerance and social repulsion in O. laqueus, animals were kept in communal tanks, and the number of dens and sex composition was varied per tank, with a set mixture of sizes and with den occupancy tracked per individual. We found that O. laqueus will socially tolerate other individuals by sharing tanks and dens, including several animals in contact and sharing a den under den-limited conditions, and with typically no loss to cannibalism or escape. However, animals also exhibit significant levels of social repulsion, and individuals often chose a solitary den when given the option. The patterns of den occupancy are observed to be consistent with a maximum entropy model. Overall, the preference to have a den is stronger than the preference to be solitary in O. laqueus, and the animals are socially tolerant of others in the tank and in a den or shelter, a first for octopuses outside mating. The relaxed disposition and social tolerance of O. laqueus make it a promising species to work with in lab, and for development into a genetic model for social behavior in octopuses.