Giant Pacific Octopus

The Giant Pacific Octopus (or, the North Pacific Giant Octopus) is the world’s largest and longest-living octopus species that are known for their high intelligence. Found in a small region of the Pacific Ocean, these creatures produce thousands of eggs, making their populations naturally resilient, though their exact numbers are not known. In some countries, they are valued as seafood, being especially popular in Asian and Mediterranean cuisines. However, they are also caught for public aquariums and as bait in other fisheries.

Giant Pacific Octopus Scientific Classification

E. dofleini
Enteroctopus dofleini

Table Of Content

Scientific Classification

Giant Pacific Octopus

E. dofleini
Enteroctopus dofleini

Giant Pacific Octopus

Physical Description & Anatomy

Size: The average length of an adult is about 15-16 feet across, which might as well be larger.

Weight: Generally, 110 to 150 pounds for a matured individual.

Body/Appearance: The skin is reddish pink, having faint venation patterns all over. The color fades to white under the tentacles.

Arms: Four pairs of arms extend from its mantle, with each pair having about 280 suckers or suction cups, which in turn are further made of many thousand chemical receptors that give them the power of sharp smell and taste.

Eyes: Eyes are circular with the retractable skin around them to protect. The vision is exceptionally sharp.

Internal Morphology: Like other octopuses, these are cool-blooded creatures, with three hearts that control their intricate circulatory and nervous systems, and nine brains to control different movements; the color of the blood is blue.


The average longevity of the Giant Pacific Octopus is 4.5 to 5 years in both captivity and the wild.

Geographic Distribution

The range of this species range extends throughout the Pacific Ocean, starting from the south of California to Alaska, stretching to the west up to the Aleutian Islands and Japan.

Habitat: Where do the North Pacific Giant Octopus Live

The Giant Octopuses dwell in the cold temperate coastal waters up to a depth of 330 feet or more in the kelp forests, rocky areas, and caves.

Giant Pacific Octopus Habitat

Giant Pacific Octopus Pictures

Classification of Species

A DNA analysis has suggested that this octopus might have three subspecies, with one being in Alaska, one in Japan, and the third one in Puget Sound, though nothing has been officially confirmed as yet.


The Giant Pacific Octopuses are exceptionally intelligent creatures. They typically live a solitary life, unless it is the time for reproduction, and are primarily nocturnal creatures, moving around at night to hunt for food. Once found, they would use their arms (not to be confused with tentacles) to hold the prey tightly, and then use their sharp parrot-beaklike mouth to puncture the flesh and tear through.

These animals are not at all aggressive (but somewhat shy and timid), and would rarely attack or bite humans unless threatened. Sometimes, an individual would spend in a cave for weeks, crawling out only when hungry. Like most other octopus species, they would squirt out black ink from their sack when attacked, and then jet away quickly.

Feeding Habits: What do the Giant Pacific Octopuses Eat

The primary diet of the Giant Octopus includes various fishes, crabs, clams, cockles, fish eggs, abalone, scallops, other octopuses, marine birds like seagulls, and even small sharks.

Mating and Reproduction

These cephalopods are polygamous. A male can mate with several females, but the female can reproduce only once in their lifetime. Both the sexes can breed year round. When it comes to mating, a single female will move out in search of a male that should be typically larger than it. When found, the pair will swim deeper into the water, within 40 and 170 feet, to search for a den where they can copulate.

The gestation period of the female is one month. It would lay the eggs in a safe den, with a single egg being the size of a rice grain, while the total count can range from anything between 18,000 and 74,000 (with an average of 50,000). The female would hang the eggs in many strands from the roof of a cave deep down in the ocean. Each of these strands holds about 200-250 eggs.

The female Giant Pacific Octopus is an example of genuine parental care, guarding the eggs for almost seven months until they hatch. During this period, the female octopus would live inside her cave without taking any food, using its arms to fan the eggs, and gushing streams of water rich in nutrients and oxygen. The female would die soon after the hatchlings come out of the eggs.

Baby Giant Pacific Octopus

Pacific Giant Octopus Eggs

Life Cycle

After birth, the baby octopuses would measure about a quarter of an inch, weighing around 22 milligrams. On the very first day of birth, the hatchlings would have 14 suckers in each of their eight arms to help them feed on tiny planktons floating in the ocean water.

By and by, the juveniles get drifted by the ocean current for about three months, feeding only on planktons. During this time, life is too hectic, and thousands of them fall prey to different creatures of the sea. Those that manage to survive and attain about 5 grams of body weight begin to settle at the bottom of the ocean.

By the time the young ones are a year old, they grow to around 2 pounds. However, to attain sexual maturity, they need to wait for a whole year during which time they are approximately 20 pounds.


Though almost all members of the octopus family can change color, this amazing creature is said to be the master of disguise in self-defense. They can protect them by changing their colors and patterns so accurately that they can blend themselves with the environment, including the minutely-detailed corals, rocks, and plants on the seabed.

Giant Pacific Octopus Anatomy

Giant Pacific Octopus Size


The adult or relatively larger octopuses practically do not have predators. However, the smaller and the young ones often fall prey to other octopuses, sea otters, seals, wolf eels, lingcod, halibuts, minks, diving birds and humans (fishermen).

Conservation Status

The IUCN Red List has not enlisted/categorized this octopus species.

Giant Pacific Octopus Tentacles

Pacific Giant Octopus

Interesting Facts

  • Each captive or aquarium pet is known to have a unique temperament and personality and can be both playful and destructive. Lab tests have shown that they can be ‘friendly’ and learn to use tools, open jars, mimic other octopuses, and even solve mazes, or recognize human faces.
  • Every year, up to 3,500 tons of these octopuses are caught in North America, where fishing and consuming octopus is not a taboo.
  • The ink of this animal is poisonous. If it releases the ink in a confined space and then fails to move away in time, it will possibly fall sick or even die by ingesting its own venom.
  • Conclusive research is going on about an entirely new species of giant octopus, closely related to the Giant Pacific, which was discovered by marine scientists in Alaska in December 2017. The specimen had fleshy frills, bumpy ridges all over the body, and two white spots on the head.
  • An adult of these cephalopods has enough strength to move more than 700 pounds.
  • The largest Giant Pacific Octopus ever caught measured about 30 feet across and weighed over 600 pounds.

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