A removal experiment with Octopus dofleini (Wulker)

Abstract

All Octopus dofleini martini were removed from a study area in Clayoquot Sound, B.C., during a 6-wk period, and they and their dens were measured. There was an exponential relation between octopus size and the size of den it occupied. In addition, small octopus tended to be found in newly dug dens, while large ones occupied natural dens. Some dens from which octopuses were removed were recolonized by animals of similar size but many remained empty and new dens were often dug in areas where dens already existed. Immigration of octopuses into the control area at the same time suggests that the observed recruitment was not brought about by the harvest. Females were more numerous than males, especially in the smallest sizes. Our study points toward the feasibility of a size-selective trap fishery. Key words: octopus, harvest, recruitment, denning, predation