Giant Pacific Octopus

Local Streams

Most octopuses live only one or two years, whereas the giant Pacific octopus is one of the longer-lived species. Females can live to about three and a half years and the males to approximately four years.

Giant Pacific Octopus

As marine biologist David Jamison is fond of saying, “We have many giants in Puget Sound”...including, the world’s largest octopus!

The giant Pacific octopus inhabits the intertidal zone to depths of nearly 2,500 feet. They range from southern California, northward along the coast of North America, across the Aleutian Islands, and southward to Japan.

Most individuals have an arm-span ranging from 7 to 20 feet in diameter and they can weigh up to 400 pounds. Females are generally larger than males. Octopuses tend to be small in warm tropical waters and larger in colder waters such as Puget Sound and the North Pacific.

Octopuses are mollusks, like clams, mussels and snails; although they are more advanced, with highly developed eyes and brains. The octopus belongs to a smaller group of mollusks called the cephalopods, which means “head-foot”; it is named because its “feet” (arms) are attached to its head. These amazing mollusks have been roaming the oceans for more than 450 million years!

An octopus has eight arms attached to the head around the mouth. Each arm has rows of suckers along the length of its arms which has many nerves. The giant Pacific octopus has two rows of suckers per arm and may have as many as 1,600 suckers total. They can actually taste with their suckers!

Octopuses are equipped with their own unique tools for penetrating hard mollusks and crustacean shells. They use their hard beaks, which are located in the mouth, to break up food and a barbed tongue to scrape up juicy prey.

The body of the octopus is called a mantle and has no bones. The mantle is a soft structure that looks like a bag, and it moves as the octopus breathes. Inside the mantle are the stomach and other organs, including three hearts.

Two hearts located at the end of each of the two gills pumps blood through the gills, and the third heart pumps the blood through the body. Octopus blood is pale blue. When the octopus breathes in, water flows over the gills and fills the mantle. When it breathes out, the water is forced out a tube called the siphon. If an octopus is trying to escape a predator, it can force water through the siphon rapidly and jet itself backwards.

The octopus has several adaptations that help them escape or hide from predators; they can temporarily blind an attacker by squirting ink at it, they have the ability to change colors, and, due to its soft body, it is able to squeeze into small spaces to hide.

What are the giant Pacific octopus’s predators and threats? Humans are one of the main threats to octopuses as humans eat octopus, as well as capture them for display and use them for fish bait. Marine mammals, such as harbor seals, sea otters and sperm whales predate on octopus, and only the largest fish, such as halibut and ling cod, are a threat to adults. A threat to Giant Pacific Octopuses is the low dissolved oxygen levels in Hood Canal in the summer months. Low oxygen levels are probably a natural condition of Hood Canal, but there are many ways that human actions have made it worse.

Adult octopuses feed on crabs, clams, snails, small fishes and even other octopuses. The octopus feeds at night and typically pounces on its target, wrapping its prey with its arms and using its beak to break open hard-shelled prey.

Most octopuses live only one or two years, whereas the giant Pacific octopus is one of the longer-lived species. Females can live to about three and a half years and the males to approximately four years.

A female octopus will lay thousands of eggs and protect them until she dies. The giant Pacific octopus lays about 50,000 eggs and tends them for about six months. During this time, she does not eat but spends all her time protecting the eggs from other animals, such as sea stars and crabs. She will only produce one nest in her life.

When the babies hatch, they are about the size of a grain of rice, and they rise up to the surface layer of the ocean as zooplankton, where they stay about six weeks. When they grow large enough to survive on the bottom of the ocean, the juvenile octopuses drift down again. It takes almost 3 years for them to grow to be as big as their parents.