Giant Pacific octopus (Enteroctopus dofleini)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Mollusca · Class: Cephalopoda · Order: Octopoda · Family: Enteroctopodidae · Genus: Enteroctopus.

Accepted name: Enteroctopus dofleini · Authority: (Wülker, 1910) · Taxonomic status: accepted · AphiaID: 342305.

Synonyms and superseded combinations recorded for this taxon: Enteroctopus dofleini apollyon (S. S. Berry, 1912); Enteroctopus dofleini dofleini (Wülker, 1910); Enteroctopus dofleini martini (Pickford, 1964); Octopus apollyon (S. S. Berry, 1912); Octopus dofleini (Wülker, 1910); Octopus gilbertianus (S. S. Berry, 1912); Octopus punctatus Gabb, 1862; Paroctopus asper Akimushkin, 1963; Paroctopus dofleini (Wülker, 1910); Polypus apollyon S. S. Berry, 1912; Polypus dofleini Wülker, 1910; Polypus gilbertianus S. S. Berry, 1912.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=342305 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Enteroctopus dofleini. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 300 cm · Depth range: 0–1500 m · Habitat zone: benthic · Vulnerability index: 90 of 100 · Fishery importance: commercial.

SeaLifeBase notes: World's largest octopus species (Refs. 106261, 106263). It's mantle length is to at least 60 cm (Ref. 96968). Common weight: 2,000 to 10,000 g (Ref. 275). Females grow larger than males (Ref. 3722). Radial spread may measure up to 9.8 m (Ref. 99323). Not found in the deep, open ocean (Ref. 106263). It is found on rocky and soft bottoms near a home crevice or cave (Ref. 865) from the low intertidal (Refs. 865, 275), to a depth of 180 meters (Ref. 865). May occur to a depth of possibly 1000 m (Ref. 106261). Also occurs on mud, sand and gravel (Ref. 10624). Found from the coast to the edge of continental shelf. Primarily benthic (Ref. 106254). Generalist predator (Ref. 106264). Mainly consumes crustaceans and mollusks. Preyed upon by large fish and marine mammals (Ref. 106263).

Source: SeaLifeBase species summary (SpecCode 58006) — https://www.sealifebase.se/summary/Enteroctopus-dofleini.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

6,965 georeferenced occurrence records for Enteroctopus dofleini are published through GBIF from 22 countries or marine areas. The map above plots 69 distinct locations from a sample of 3,000 records, omitting 49 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: United States of America (5,547); Canada (1,141); Korea, Republic of (164); Japan (59); Russian Federation (19).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2289485) — https://www.gbif.org/occurrence/search?taxon_key=2289485&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=342305 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Enteroctopus dofleini (Wülker, 1910) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 162958) — https://www.iucnredlist.org/species/162958/0; GBIF IUCN Red List category endpoint (taxonKey 2289485) — https://api.gbif.org/v1/species/2289485/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Its spatial distribution encompasses much of the coastal North Pacific, from the Mexican state of Baja California, north along the United States' West Coast (California, Oregon, Washington and Alaska, including the Aleutian Islands), and British Columbia, Canada; across the northern Pacific to the Russian Far East (Kamchatka, Sea of Okhotsk), south to the East China Sea, the Yellow Sea, the Sea of Japan, Japan's Pacific east coast, and around the Korean Peninsula. It can be found from the intertidal zone down to 2000 m, and is best-adapted to colder, oxygen- and nutrient-rich waters. It is the largest octopus species on earth and can often be found in aquariums and research facilities in addition to the ocean. E. dofleini play an important role in maintaining the health and biodiversity of deep sea ecosystems, cognitive research, and the fishing industry.

The giant Pacific octopus was first described in 1910 by Gerhard Wülker of Leipzig University in Über Japanische Cephalopoden. He describes the species' morphology in detail, and mentions that there seems to be much variation within the species. The specific name dofleini was chosen by Gerhard Wülker in honor of German scientist Franz Theodor Doflein. It was moved to genus Enteroctopus by Eric Hochberg in 1998.

E. dofleini is distinguished from other species by its large size. It is the largest octopus species. Adults usually weigh around 15 kg, with an arm span up to 4.3 m. The largest individual weighed in at 600 lb, with a radial span of 32 ft.

American zoologist G. H. Parker found that the largest suckers on a giant Pacific octopus are about 6.4 cm and can support 16 kg each.

E. dofleini preys on shrimp, crabs, scallops, abalones, cockles, snails, clams, lobsters, fish, squid, and other octopuses. Food is procured with its suckers and then bitten using its tough beak of chitin. It has also been observed to catch spiny dogfish (Squalus acanthias) up to 4 ft in length while in captivity. Additionally, consumed carcasses of this same shark species have been found in giant Pacific octopus middens in the wild, providing strong evidence of these octopuses preying on small sharks in their natural habitat. In May 2012, amateur photographer Ginger Morneau was widely reported to have photographed a wild giant Pacific octopus attacking and drowning a seagull, demonstrating that this species may eat any available source of food within its size range, even birds.

Scavengers and other organisms often attempt to eat octopus eggs, even when the female is present to protect them. Giant Pacific octopus paralarvae are preyed upon by many other zooplankton and filter feeders. Marine mammals, such as harbor seals, sea otters, and sperm whales depend upon the giant Pacific octopus as a source of food. Pacific sleeper sharks are also confirmed predators of this species. In addition, the octopus (along with cuttlefish and squid) is a significant source of protein for human consumption. About 3.3 e6tonne are commercially fished, worth $6 billion annually. Over thousands of years, humans have caught them using lures, spears, pot traps, nets, and bare hands. The octopus is parasitized by the mesozoan, which lives in its renal appendages.

E. dofleini move through the open water using jet propulsion, which is achieved by drawing water into its body cavity and then forcefully expelling it through a siphon, creating a powerful thrust and propelling the octopus through the water at a high speed. When moving on the seafloor, however, the octopus crawls using its arms.

E. dofleini remain stationary or in hiding 94% of the time, usually concealed within dens, kelp, or camouflaged in their environment. Otherwise, they exhibit activity throughout the day, increasingly so from midnight to the early morning. While stationary, E. dofleini hide, groom, eat, sleep, and maintain dens. E. dofleini are capable of moving vast distances to occupy new areas or habitats, with large octopuses moving further than smaller ones. Their movements are not random; they demonstrate a preference for habitats with dense kelp cover and rocky terrain suggesting a sophisticated level of habitat selection, likely optimizing foraging efficiency and minimizing exposure to predators. Furthermore, their movement patterns include direct relocations to new areas and central-tendency movements to return to familiar habitats. This navigation behavior is influenced by the use of familiar cliff edges, substrates, and topography as well as visual navigation.

E. dofleini migration patterns vary depending on the population. In the eastern Pacific waters off the coast of Japan, migration coincides with seasonal temperature changes in the winter and summer. Here, E. dofleini migrate to shallower waters in the early summer and winter and offshore in the late summer and winter. There is no evidence of these migration patterns in the Alaskan and northeast Pacific populations of E. dofleini.

E. dofleini are den dwellers, which serve as a central point from which they forage while also providing protection, shelter, and privacy. After hunting, they bring food back to the den to feed in a safer environment and avoid predators. Shells, bones, and other feeding debris pile up outside of the den, creating "den litter" that is commonly used by scientists and divers to find E. dofleini.

Unlike most other octopus species, whose lifespans normally last only one year, the giant Pacific octopus has a lifespan of three to five years. They reach sexual maturity at one to two years of age. Gonadal maturation has been linked to the optic gland of octopuses which has been compared functionally to the vertebrate pituitary gland. These optic glands are the only endocrine glands identified in octopuses, and their secretions have been found to contribute to behaviors linked with reproduction and senescence. When removed, females no longer brood their eggs, resume feeding, increase in weight, and experience longer lifespans compared to sexually mature, brooding females who still retain their optic glands.

To help compensate for its relatively short lifespan, the octopus is extremely prolific. It can lay between 120,000 and 400,000 eggs which are coated in chorion, and attached to a hard surface by the female. The spawn is intensively cared for exclusively by the female, who continuously blows water over it and grooms it to remove algae and other growths. While she fulfills her duty of parental care the female stays close to her spawn, never leaving to feed, leading to her death soon after the young have hatched. The female's death is the result of starvation, as she subsists on her own body fats during this period of approximately 6 months. Hatchlings are about the size of a grain of rice, and very few survive to adulthood. Their growth rate is quite rapid: starting from 0.03 g and growing to 20 - 40 kg at adulthood, which is an increase of around 0.9% per day. The giant Pacific octopus' growth over the course of a year has two sections: a faster section, from July to December, and a slower section, from January to June. Because they are cool-blooded, they are able to use most of their consumed energy for body mass, respiration, physical activity, and reproduction. During reproduction, the male octopus deposits a spermatophore (or sperm packet) more than 1 m long using his hectocotylus (specialized arm) in the female's mantle.

Source: Wikipedia: Giant Pacific octopus — https://en.wikipedia.org/wiki/Giant_Pacific_octopus (CC BY-SA 4.0). Accessed 2026-09-23.

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