--- title: "Giant Pacific Octopus (Enteroctopus dofleini) | AnimalTracks.wiki" description: "Three brains, three hearts, blue copper blood, and skin that changes color and texture." image: "https://animaltracks.wiki/images/animals/giant-pacific-octopus-1.webp" published: "2026-08-31" updated: "2026-09-16" --- # Giant Pacific Octopus (*Enteroctopus dofleini*) > **Status**: Checked against 7 sources, listed under Sources below. > **Tagline**: Three brains, three hearts, blue copper blood, and skin that changes color and texture. > **Soundtrack Vibe**: Trip-Hop & Velvet Downtempo // Radiohead, "Everything In Its Right Place" > **Soundtrack Links**: [Spotify](https://open.spotify.com/track/31DVVa40JpTudyGDNC1ROW) | [YouTube](https://www.youtube.com/watch?v=NUnXxh5U25Y) > **Vibe Match**: Shape-shifting experimental electronics for an octopus with three brains, whose layered pigment cells shift its skin between pale grey and dark red. ## Biological Superpowers & Stats - **Taxonomy**: *Enteroctopus dofleini* - **Danger Level**: Low - **Conservation Status**: Least Concern ([IUCN Red List](https://doi.org/10.2305/iucn.uk.2018-2.rlts.t162958a958049.en)) - **Superpower**: Three hearts, blue copper-rich blood, about 2,140 to 2,240 suckers that grip, taste, and smell, and a body that can squeeze through any hole large enough for its beak. - **Habitat**: Kelp fields, dens, and crevices across the temperate North Pacific, from southern Baja California to Alaska, the Aleutians, and Japan - **Diet**: Shrimp, crabs, scallops, clams, lobster, fish, and soft-bodied prey - **Tags**: cephalopod, ocean, carnivore, giant-size ## Natural History & Behavior ## A Giant on a Five-Year Clock The giant Pacific octopus (*Enteroctopus dofleini*) is the largest octopus species in the world. It weighs 22 to 110 pounds, averaging 45 to 65, though Canadian researchers once recorded one at 156 pounds, and it reaches that weight in about five years. Its arms can span up to 31 feet across. Its whole life is thought to last just 3 to 5 years. It ranges through temperate Pacific waters, from southern Baja California north to Alaska, west to the Aleutian Islands and south again to Japan. It is generally found from shallow tide pools down to 110 meters (361 feet), though it has turned up more than 1,500 meters (4,921 feet) down. It spends most of its life alone, often in kelp fields, sheltering in dens and crevices floored with sand, mud or gravel. Shells from its meals pile up outside the den as a midden. ## Three Hearts and No Bones Two of its three hearts pump blood to its gills, and the third pumps it to the rest of the body. That blood is blue, from a copper-rich protein called hemocyanin. It has three brains, too. An adult's eight arms carry about 2,140 to 2,240 suckers, which give it a powerful grip and a sense of taste and smell. Its parrot-like beak is the only hard part of its body, and it can squeeze through any hole large enough for that beak: a 50-pound octopus can fit through a two-inch hole. Its suction discs are quite effective, and Alaska's state wildlife agency notes that octopuses have been able to unscrew jar lids from inside the jar. > **Built to Vanish** Layered pigment cells called chromatophores let it shift between pale grey and dark red, and it can also change the texture of its skin to blend into its surroundings. ## A Short, Strange Life Its diet is mostly clams, crabs, fish and squid. In one study, it pulled apart mussels and Manila clams, the thinnest-shelled prey on offer, but got into littleneck clams by chipping the shell or drilling through it, presumably to inject a toxin. In another, eight octopuses were each exposed to two unfamiliar people, one who fed them and one who touched them with a bristly stick. After two weeks they showed a different body pattern and reached their arms differently toward each person, and the four larger ones changed how fast they breathed. Females mate only once in their lives, and males die a few weeks after mating. About 40 days after mating, a female finds a rocky den and lays up to 100,000 eggs in long strands. She guards and cleans them without eating and slowly starves, dying around the time they hatch. Most octopus species go through extreme physical decline after a single breeding bout. In giant Pacific octopuses kept in US public aquariums, researchers found that this decline, called senescence, changes how they respond to light touch and painful stimuli, and that the arm tips of terminally senescent animals had a lower density of nerve and skin cells than those of healthy octopuses that had not yet bred. The IUCN rates the species Least Concern. Oceana says scientists believe its numbers are stable, but little is known about its overall population size. Its short life and reclusive nature also make it hard to study. ## Frequently Asked Questions ### How many brains and hearts does a giant Pacific octopus have? Three of each, alongside its eight arms. Two of its hearts pump blood to the gills, and the third pumps it to the rest of the body. *(Source: [Alaska Department of Fish and Game]())* ### Why is giant Pacific octopus blood blue? Its blood is blue because of hemocyanin, a copper-rich protein in its bloodstream. *(Source: [Alaska Department of Fish and Game]())* ### How small a gap can a giant Pacific octopus squeeze through? Its parrot-like beak is the only hard part of its body, and it can squeeze through any hole large enough for that beak. Alaska's state wildlife agency says a 50-pound octopus can fit through a hole two inches across. Its suction discs are quite effective too: octopuses have been able to unscrew jar lids from inside the jar. *(Source: [Alaska Department of Fish and Game]())* ### Can a giant Pacific octopus really tell people apart? In one study, eight octopuses were each exposed to two unfamiliar people over two weeks: one fed them and the other touched them with a bristly stick. By the end, the octopuses showed a different body pattern and reached their arms toward or away from each person differently, and the four larger ones changed their breathing rate. The researchers took this as evidence that octopuses can recognize individual humans. *(Source: [Anderson et al. 2010]())* ## Sources 1. [Giant Pacific Octopus (Enteroctopus dofleini) Species Profile. Alaska Department of Fish and Game.]() 2. [Enteroctopus dofleini (giant Pacific octopus). Animal Diversity Web, University of Michigan.]() 3. [Giant Pacific Octopus. Oceana Marine Life Encyclopedia.]() 4. [Anderson et al. (2010). Octopuses ( Enteroctopus dofleini ) Recognize Individual Humans. Journal of Applied Animal Welfare Science.]() 5. [Holst et al. (2022). Behavioral changes in senescent giant Pacific octopus (Enteroctopus dofleini) are associated with peripheral neural degeneration and loss of epithelial tissue. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology.]() 6. [Anderson & Mather (2007). The packaging problem: Bivalve prey selection and prey entry techniques of the octopus Enteroctopus dofleini. Journal of Comparative Psychology.]() 7. [Allcock, Taite & Allen (2018). Enteroctopus dofleini. The IUCN Red List of Threatened Species 2018: e.T162958A958049.]() *Published August 31, 2026. 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