This photo was taken on 9 June, 2012 at: Monterey Bay Aquarium, California, USA
Feeding behavior: This octopus hides in its den under rocks or in a cave. By night, an octopus leaves its den to hunt after its favorite prey such as crustaceans, small crabs, scallops, abalone, snails, clams and fish. Octopuses in general when feed on hard-shelled prey may crack shells and pull it apart, bite it open with their beak or drill through the shell. Octopuses may create a tiny hole in the prey shell. Through this hole, octopus secretes and injects a toxin (venom) that paralyzes their prey to be ready for consumption.
Predation: The predation on octopus is always done by marine mammals such as Harbor Seals, Sea Otters, and Sperm whales which depend upon the Giant Pacific Octopus as a source of food. When octopuses got threatened, they often try to escape by releasing an ink cloud and change their own color. The ink is toxic and so if the octopus cannot escape their own ink (or water is not changed quickly when held in an aquarium), they will become ill or perhaps die. Changing skin color is activated by contracting or expanding pigment cells (chromatophores) in the skin in an attempt to match the background color through the adjustment of the three colors which exist in three bags located in pigment cells.
References: Giant Octopus: Fact Sheet; Aquaria poster; Wikipedia; Marinbio
Note 1: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Note 2: More information on this species is available in two posts in the video library on this site
