Giant Pacific Octopus Facts

The biggest octopus in the world

Giant Pacific octopus or North Pacific giant octopus (Enteroctopus dofleini)
Giant Pacific octopus or North Pacific giant octopus (Enteroctopus dofleini). Andrey Nekrasov / Getty Images

The giant Pacific octopus (Enteroctopus dofleini), also known as the North Pacific giant octopus, is the largest and longest-lived octopus in the world. As its common name suggests, this large cephalopod lives along coastlines of the North Pacific Ocean.

Fast Facts: Giant Pacific Octopus

  • Scientific Name: Enteroctopus dofleini
  • Other Name: North Pacific giant octopus
  • Distinguishing Features: Reddish-brown octopus with large head, mantle, and eight arms, usually identified by its large size
  • Average Size: 15 kg (33 lb) with arm span of 4.3 m (14 ft)
  • Diet: Carnivorous
  • Average Lifespan: 3 to 5 years
  • Habitat: Coastal North Pacidic
  • Conservation Status: Not evaluated
  • Kingdom: Animalia
  • Phylum: Mollusca
  • Class: Cephalopoda
  • Order: Octopoda
  • Family: Enteroctopodidae
  • Fun Fact: Despite its large size, it can escape any container with an opening large enough for its beak.

Description

Like other octopuses, the giant Pacific octopus exhibits bilateral symmetry and has a bulbous head, eight sucker-covered arms, and a mantle. Its beak and radula are at the center of the mantle. This octopus is generally reddish-brown, but special pigment cells in its skin change texture and color to camouflage the animal against rocks, plants, and coral. Like other octopuses, the giant Pacific octopus has blue, copper-rich blood that helps it obtain oxygen in cold water.

The giant Pacific octopus is a master of disguise. Can you see it against the coral?
The giant Pacific octopus is a master of disguise. Can you see it against the coral?. Andrey Nekrasov / Getty Images

For an adult-age giant Pacific octopus, the average weight is 15 kg (33 lb) and the average arm span is 4.3 m (14 ft). Guinness World Records lists the largest specimen as weighing 136 kg (300 lb) with an arm span of 9.8 m (32 ft). Despite its large size, the octopus can compress its body to fit through any opening larger than its beak.

The octopus is the most intelligent invertebrate. They have been known to play with toys, interact with a handler, open jars, use tools, and solve puzzles. In captivity, they can distinguish between and recognize different keepers.

Distribution

The giant Pacific octopus lives in the Pacific Ocean off the coasts of Russia, Japan, Korea, British Columbia, Alaska, Washington, Oregon, and California. It prefers cool, oxygenated water, adjusting its depth from the surface down to 2000 m (6600 ft) as required.

E. dolphleini distribution
E. dolphleini distribution. Kat O'Brien

Diet

Octopuses are carnivorous predators that usually hunt at night. The giant Pacific octopus appears to feed on any animal within its size range, including fish, crabs, clams, small sharks, other octopuses, and even seabirds. The octopus grabs and restrains prey using its tentacles and suckers, then bites it and tears away flesh with its tough beak.

Predators

Adult and juvenile giant Pacific octopuses are preyed upon by sea otters, harbor seals, sharks, and sperm whales. The eggs and paralarvae support zooplankton filter feeders, such as baleen whales, some species of sharks, and many species of fish.

The giant Pacific octopus is an important protein source for human consumption. It is also used as bait for Pacific halibut and other fish species. About 3.3 million tons of giant octopus are fished annually.

Reproduction

The giant Pacific octopus is the longest-lived octopus species, usually living 3 to 5 years in the wild. During this time, it leads a solitary existence, breeding only one time. During mating, the male octopus inserts a specialized arm called a hectocotylus into the female's mantle, depositing a spermatophore. The female can store the spermatophore for several months before fertilization. After mating, the male's physical condition deteriorates. He stops eating and spends more time in open water. Males typically die of being preyed upon, rather than starving to death.

Giant Pacific octopus with her eggs
Giant Pacific octopus with her eggs. FriedC

After mating, the female stops hunting. She lays between 120,000 and 400,000 eggs. She attaches the eggs to a hard surface, blows fresh water over them, cleans them, and chases away predators. Depending on water temperature, the eggs hatch in about six months. Females die soon after the eggs hatch. Each hatchling is about the size of a grain of rice, but grows at the rate of about 0.9% per day. Although many eggs are laid and hatch, most hatchlings are eaten before they reach adulthood.

Conservation Status

The giant Pacific octopus has not been evaluated for the IUCN Red List, nor is it protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora. This is because it's too hard to find and track the animals to assess its numbers. While not endangered, the species is likely threatened by pollution and climate change. Usually, the octopus flees warm water and dead zones in favor of cooler, oxygenated water, but some populations may be trapped between low-oxygen zones. Yet, the species can adapt to live in deep water, so it may be possible for the giant Pacific octopus to find a new habitat.

Sources

  • Cosgrove, James (2009). Super Suckers, The Giant Pacific octopus. BC: Harbour Publishing. ISBN 978-1-55017-466-3.
  • Mather, J.A.; Kuba, M.J. (2013). "The cephalopod specialties: complex nervous system, learning and cognition". Canadian Journal of Zoology. 91 (6): 431–449. doi:10.1139/cjz-2013-0009