giant Pacific octopus
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Giant Pacific Octopus

Enteroctopus dofleini

Distribution and Habitat:

Northern Pacific Ocean from southern California, north along the coast of North America's Pacific northwest and south to Japan. The giant Pacific octopus inhabits a wide range of depths, from shallow coastal waters to depths of at least 1,500 meters.

Physical description:

The giant Pacific octopus is the largest octopus species in the world. Each of its eight arms may measure over six feet, and it has an arm span of more than 14 feet. Females are generally larger than males. This cephalopod's loose, billowy skin varies from coral colored to mottled white.


Predators of the giant Pacific octopus include the harbor seal, sperm whale, and sea otter.


The giant octopus usually feeds on bivalves, crabs, and lobster, but will eat a range of species. They have also been observed eating fish, sharks, and even birds.

Feeding behavior:

Octopuses are equipped with several tools for penetrating stubborn mollusk and crustacean shells. An organ called the salivary papilla is covered with small teeth, which can bore through shells. It also delivers salivary secretions to the drilled hole that further corrode the shell. In addition, saliva weakens the prey and detaches it from its shell. Octopuses use their hard beaks to break up food and a barbed tongue called the radula scrapes up juicy prey.

Most octopuses hunt at night. It is thought that they scout out promising feeding grounds by sight and then extend their sucker-studded arms to explore the area by touch. Mature female E. dolfeini have 280 suckers on each arm, each sucker containing thousands of chemical receptors. The sensitivity of an octopus's suckers to touch and taste allow it to grope for food in small, dark crevices. When an octopus makes a delectable discovery, it lunges and delivers the prey to its mouth.

Life span:

Like most cephalopods, the giant Pacific octopus has a brief life span of only three to five years.


Males possess a modified sex arm called a hectocotylus that stores long ropes of sperm, up to one meter long. During mating, he inserts the rope of sperm, called a spermatophore, into the female's oviduct. The female lays 20,000 to 100,000 eggs in several strings, which she hangs in her den. She broods obsessively, cleaning, and aerating the eggs and not eating until they hatch about seven months later. Females die shortly after eggs hatch, and males die several months after mating.


Although no octopuses are protected by CITES or the IUCN Red List, too little is known about octopus populations to determine whether or not they are threatened. Octopuses are sensitive to polluted water.

Did you know...

Octopuses establish dens in crevices, under rocks, or in man-made objects like flowerpots. They use dens to lay eggs and hide from predators. Their soft, fleshy bodies lack shells, allowing them to squeeze into tiny spaces.