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Giant Pacific Octopus

Giant Pacific Octopus illustration by Ivan Phillipsen

Dwelling in the cold waters along the rocky coast of the Pacific Northwest is an otherworldly creature.

It has three hearts, which pump pale blue blood through its boneless, rubbery body. Its large brain encircles its throat and extends down into each of its eight arms, giving these appendages an eerie ability to crawl away on their own if severed. Individuals can reach an incredible size: up to 30 feet across and weighing 600 pounds. Despite being colorblind, this creature can quickly change its skin color to match its surroundings, making it virtually invisible to harbor seals, sperm whales, and sea otters – its natural predators.

I am talking, of course, about the Giant Pacific Octopus.


Giant Pacific Octopus (photo by Taollan82 on Wikipedia)

The Giant Pacific Octopus (Enteroctopus dofleini) is a mollusk, making it a relative of clams, oysters, slugs, and snails. Among mollusks– and all other invertebrates, for that matter– octopuses are the undisputed geniuses. They are also very smart in comparison to most vertebrate animals. A Giant Pacific Octopus is at least as smart as your dog or cat.

The Intelligence of the Giant Pacific Octopus

In laboratory tests, Giant Pacific Octopuses are able to distinguish shapes and patterns, solve mazes, and twist open jar lids. They have individual personalities, which means that their actions aren’t the result of genetically-determined instincts alone. Intelligence and curiosity are revealed in many of their behaviors. For example, inquisitive octopuses sometimes swim up to “taste” and fondle the masks of human divers with their tentacles.

Captive octopuses have crawled out of their aquariums at night to flop into neighboring tanks, where they feasted on small fish. Fully satisfied with their surreptitious meals, they shuffled back to their own tanks, leaving puddles of evidence behind.

The Giant Pacific Octopus engages in REM sleep and shows brainwave patterns during sleep which suggest that these animals may have the ability to dream. They may even posses conciousness.

The idea that an invertebrate might possess some of the same mental abilities as us brainy primates leaves some people in awe and others in skeptical disbelief.

Color Changing Ability

Pigmented skin cells called chromatophores and iridophores allow these clever camouflagers to blend in with their surroundings. Interestingly, this skill has nothing to do with their eyesight, since octopuses are color-blind. Iridophore cells compensate for this shortcoming by sensing the brightness of the surroundings, and the chromatophore pigments are what allow for most of the alteration of color.

An octopus appears whitish when resting. This is because each chromatophore cell is surrounded by muscle tissue, and when this muscle tissue is relaxed, the color-changing property of these pigment-filled cells is not activated. However, when gliding across a seafloor or escaping from a predator, these muscles contract, causing the chromatophores to activate and conceal the octopus from potential danger. This amazing adaptation is an octopus’s greatest defense. Speedy swimming– made possible by forceful jets of water being squirted out of the octopus’s body– is also a very useful ability in dangerous situations.

Catching Prey

Giant Pacific Octopuses are well equipped with the necessary tools to catch and feed on their prey, which include shrimp, crabs, scallops, and small fishes. In total, their 8 arms house an array of approximately 2,000 suckers, each of which is capable of both tasting and snaring prey.

Once caught, prey is brought up to the sharp, piercing beak made up of chitin. The only non-squishy part of an octopus is this beak. Like most mollusks, octopuses possess a barbed tongue called a radula, which is a handy tool for scraping crustaceans out of their shells.

Giant Pacific Octopuses in the Pacific Northwest

The ideal habitat for the Giant Pacific Octopus is a rocky shoreline with temperate water that remain near 50° F. However, this species is well known for its adaptability, which enables it to inhabit the entire west coast, from southern California up to Alaska, as well as areas around Japan.


Giant Pacific Octopus (photo from NOAA)

The Pacific Northwest is an excellent home for these creatures: the average water temperature off the Oregon and Washington coasts is around 48-56° F (depending on the location and season), and the volcanic rocks of the coast are riddled with caves. Caves provide shelters for octopuses and are especially important to females. A female octopus needs a small cave to care for her several thousand eggs for up to 6 months.

Divers frequently encounter Giant Pacific Octopuses in the waters of Puget Sound. Teams of volunteer divers, led by researchers from the Seattle Aquarium, have surveyed Puget Sound each year for 10 years. Typical yearly counts are about 70 octopuses. This is only a very rough estimate of population size. (If you are a diver and would like to help count octopuses, you can find information at the Seattle Aquarium website)

Despite the high concentration of toxic pollution in areas like Puget Sound, the Giant Pacific Octopus seemingly continues to thrive in the Pacific Northwest. In fact, they sometimes use trash such as car tires and bottles to build shelters.

Although the Giant Pacific Octopus is not considered endangered, little is known about the size of the world’s population. Not surprisingly, one of the species biggest threats is human influence, including environmental destruction and commercial fishing. Their continued presence in Puget Sound is possibly a testament to their resilience. But we really don’t know how well they are doing there and we don’t know the extent of their ability to survive in toxic environments.

The Giant Pacific Octopus is a marvelous animal that we can hope will continue to prowl the shores of the Pacific Northwest for a long, long time. Click here for a great video of these animals in the wild.

Where you can go in the Pacific Northwest to see a Giant Pacific Octopus up close


Marine Life Center, Bellingham, Washington
Point Defiance Zoo and Aquarium. Tacoma, Washington
Feiro Marine Life Center, Port Angeles, Washington
Port Townsend Marine Science Center, Port Townsend, Washington
Poulsbo Marine Science Center, Keyport, Washington
Seattle Aquarium, Seattle, Washington


Oregon Coast Aquarium, Newport, Oregon
Seaside Aquarium, Seaside, Oregon
Hatfield Marine Science Center, Newport, Oregon

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6 comments… add one

  • Ilona Marshall September 24, 2011, 5:02 PM

    Presently, I am creating a headdress of a giant pacific octopus for a wearable art awards competition which takes place in Feb.2012, in Port Moody, British Columbia. In 2011, I created a salmon headdress and won an honorable mention award.
    I would love to see some still photos of these amazing animals and ask if you are aware of any of them ever being caught in the nets of fisherman. I want to create a headdress that will inspire people to be aware of this amazing beautiful octopus and support its conservation..

  • anny scoones December 27, 2011, 6:12 PM

    Greetings, I found a very pink dead octopus washed up on our Victoria shore this morning. Just wondering what species it might be.
    It was a lovely pink colour with white suckers, not very big – it’s head was say, about eight inches across and one arm may have been two feet long.
    Perhaps a young giant pacific octopus? I am curious as to other species in this area . . .any thoughts would be appreciated.

    • Ivan Phillipsen December 30, 2011, 2:49 PM

      Hi, Anny. Thanks for the question. While I am no expert on our local cephalopods, I would say from your description that, yes, what you saw was probably a small Giant Pacific Octopus. Lucky you! Too bad it was dead, though.

  • Michael Barton November 9, 2012, 7:23 PM

    The new Portland Aquarium opens in Milwaukie this December. I think they will have a Giant Pacific Octopus so you may have to update your list!

  • Benjamin Yu June 5, 2014, 9:38 AM

    Your article helped a lot! I’m writing a report on octopuses, so your article helped a lot! This article increased my love for octopuses!

  • Julia Chase September 15, 2014, 12:50 PM

    I am in 7th grade and found this very helpful for on of my science reports. I thought it has much wider range of facts than the other sites I found!
    Thanks Ivan!!!!


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