Giant Pacific Octopus (Enteroctopus dofleini)

Giant Pacific octopus at the Seaside Aquarium (photo credit: Lauren Rice)

Other Names: GPO

Description: Although it is the largest octopus in the world, the giant Pacific octopus is a rare find at Haystack Rock. The giant Pacific octopus is usually dark red or brownish-red but can change color almost immediately to camouflage. Based on existing data, these creatures can have arms that reach 9 meters (almost 30 feet) in length. Each of these arms has round suction cups on it that the octopus uses to grab prey and pry it open!

Habitat: Geographically, it is found on both sides of the Pacific Ocean; it can be found from Alaska to northern California along the West Coast of North America, and on the other side of the Pacific it can be found Korea, Japan, and Siberia’s coastlines.

Diet: Giant Pacific octopus prey on clams, crabs, and other sea creatures. Their predators include seals, sea otters, large fish, and sharks. It’s found in the intertidal zone usually in depths around 1,500 meters (almost 5,000 feet). 

Tide Pool Tidbits:

  • When a giant Pacific octopus is found in tide pools (like at Haystack Rock), it is usually a juvenile that got trapped when the tide went out (they’re still learning how to avoid getting trapped!)

  • The grip strength of a giant Pacific octopus is quite impressive: the larger suction cups near its mouth can hold weights of up to 35 pounds!

  • Octopuses have three hearts and nine brains! One brain is located in each of their eight arms, and the ninth brain is located in their head. They also have blue blood!

  • The only hard and solid part of an octopus’s body is its beak (which is located in its mouth and looks similar to the beak of a parrot). The rest of its body is very soft. Therefore, an octopus can fit its entire body through tiny little holes as long as its beak is smaller than the hole! 

  • Although octopuses don’t look much like other mollusks such as snails, they still have the same features like a mantle, a radula, and more.

  • Out of all invertebrates, octopuses are considered to be the smartest. Their intelligence has been said to be similar to that of a household cat. Because of how intelligent they are, octopuses living in places like aquariums need consistent enrichment through activities like games and puzzles.

Reference: Central Coast Biodiversity, Oregon Coast Aquarium