Giant Pacific Octopus | Oceana Canada

Canadian Marine Life Encyclopedia

Giant Pacific Octopus

Enteroctopus dofleini

Also known as

North Pacific giant octopus

Distribution

Northern Pacific Ocean from Japan to California and Alaska. Found off the coast of British Columbia.

Écosystèmes/habitats

Coastal intertidal areas to waters deeper than 100m

Feeding Habits

Predators

Conservation Status

Not listed

Taxonomie

Order Octopoda, Family Octopodidae

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Like other octopuses, the giant Pacific octopus is extremely intelligent and has been observed opening jars and are even known to recognize caregivers in captivity. This makes sense considering they have nine brains! They also have eight arms and three hearts. Two of the three hearts pump blood to the gills, while the third circulates blood to the rest of the body. Octopuses use one central brain to control their nervous systems and a small brain in each arm to control movement. They’re also known for having blue blood thanks to a copper-rich protein called hemocyanin in their bloodstream, which is used for oxygen transport.

The giant Pacific octopus is the largest octopus in the world, weighing 50 kilograms or more and measuring up to 9 metres. They are usually a deep orange-brown colour, but they have sophisticated camouflage capabilities. Specialized cells called chromatophores allow these and other octopuses to change their skin colour and texture in one tenth of a second. Additionally, these highly intelligent animals can secrete ink from an internal ink sac in order to distract predators. Their diet primarily consists of crabs, prawns, molluscs and small fish, which they often take back to their den to eat. They move either by crawling with their arms or jet propulsion, which involves pushing water out of their siphons.

The giant Pacific octopus starts life as tiny as a grain of rice, living in the surface water of the oceans for the first three months of their life. Individuals reach sexual maturity at around two to three years of ag, though they only live to be about four to five years old. Even with this short lifespan, they are still considered one of the longest-living octopus species. 

After mating, females will search for a den where they will lay their eggs on the ceiling. Both males and females are semelparous, meaning they only reproduce once in their lifetime. Males usually die shortly after mating, while females devote all energy to egg protection. Females will stop eating while protecting their eggs over the five to 10-month development period. The protection they provide is essential for the eggs to survive and hatch. Shortly after the eggs hatch, starvation and disease complications often result in the mother’s death.

Commercial fisheries for the giant Pacific octopus off the coast of British Colombia historically included directed trap and dive fisheries, as well as permitted landings from bycatch in some trap and trawl fisheries. Landings fluctuated widely, peaking at 217 tonnes in 1997 but have been decreasing annually since 2002. 

In 2007, Fisheries and Oceans Canada (DFO) licensed the octopus by dive harvest using a non-transferable exploratory fishing licence, with consultations to convert to a commercial licensing system since 2009. In the dive fishery, octopus are harvested by SCUBA divers who search for dens and when they find one occupied, disturb the octopus with an irritating substance and capture it in a net or bag. 

Currently there are no records available for recreational and First Nations harvest of octopus, although recreational harvests are permitted and several First Nations communities harvest octopus for food, social, and ceremonial purposes. They continue to be captured as bycatch in trap and trawl fisheries, although mortality associated with octopus that are accidentally caught by trap are likely low if released quickly and safely.

Lack of data and specific management strategies for these octopuses make it difficult to understand fishing impacts. Fisheries and Oceans Canada collects some octopus data through spot prawn and Dungeness crab fisheries’ trap surveys, but no formal stock assessments have been conducted in recent years, and few management measures exist.

Giant Pacific octopuses are an elusive species, with little commercial significance in Canada, making data on their populations limited. As such, there are no current specific management strategies in place for the giant Pacific octopus in Canada. The species is not assessed by COSEWIC or the IUCN.