Meeting Abstract
In 2014 a population of smoothskin octopuses (Muusoctopus leioderma) was discovered in Burrows Bay, WA at a depth of 13m, the shallowest recorded depth for this deep water species. The occurrence of these octopuses in shallow water raises the question what is the prefered temperature for this octopus species.The average temperature at the east entrance of the Strait of Juan de Fuca near Bowman’s Bay at depth near the upper limit of the known range of M. leioderma of 113m is 7 °C and the temperature of Burrows Bay where octopuses have been collected is 13°C. This creates two possible temperature preferences for M. leioderma, deep water (7°C) or shallow water (13°C). The purpose of the study was to determine the temperature preference of M. leioderma, as a lower temperature preference would support the hypothesis that this population is a recent immigrant to shallow water. Temperature preference of 17 Muusoctopus leioderma was determined using a thermal gradient, during three hour trials. Also, total movement was measured over a range of temperatures (4,7,9,11,13°C) in a shallow, temperature controlled aquarium. Movement of octopuses during the thermal gradient and activity trials was recorded with cameras taking time-lapse images every 20 seconds. Oxygen consumption was measured using open respirometry at a range of temperatures (4, 7, 10, 13°C) over 10 hours. This data did not show that Muusoctopus leioderma has a strong preference between 7 and 13°C. The lack of evidence for a temperature preference does not support either hypothesis for this population of M. leioderma being a recent immigrant to shallow water in the Salish Sea or if there is a long term population.
