UCB Moorea Class: Biology and Geomorphology of Tropical Islands

Octopuses are known for the advanced behaviors and elaborate displays used in predator avoidance. Although studies have provided anecdotal evidence on the defense mechanisms of these animals, whether these behaviors vary under light and dark conditions is unknown. This study investigated the diurnal and nocturnal predator defense mechanism s of Octopus bocki (Adams, 1941) in Moorea, French Polynesia. Seven behaviors were identified as primary defense mechanisms for protection from fish predators during daylight and nighttime hours. Rates of occurrence and durations for defense behaviors significantly differed between diurnal and nocturnal conditions, as O. bocki frequently Crawled during the daylight hours , but sat still and Curled during the nighttime hours. Results indicate that O. bocki modifies predator defense behaviors for survival under light and dark conditions.