Shelter Utilization by the Molluscan Cephalopod Octopus bimaculatus

Octopus bimaculatus, a common member of subtidal and intertidal communities of southern California (USA), 1s found in a wide range of habitats at Santa Catalina Island, where it is equally abundant in holes, under rocks, and in crevices.Although shelters may b e scarce in some areas, it appears that shelters generally do not limit the size of 0. bi~naculatus populations Shelters suitable for habitation by adult and juvenile 0. birnaculatus were always in excess during this study.Nearly half of the population studied inhabited their shelter for more than a month, and a few octopuses occupied the same shelter for at least 5 months.O n e fourth of the population spent less than a week in the same shelter, and many of these may have changed shelters every day.However, nearly all octopuses remained in the same area.The nontransient behavior of 0. bimaculatusmay have important implications for resource utilization, mating and agonistic behavlor