How smart is a giant Pacific octopus? Giant Pacific octopuses are smart: they can learn to open jars. A giant Pacific octopus has a well-developed brain. National Wildlife magazine reported that scientists believe octopuses are more intelligent than any fish, though not as smart as most mammals.

According to the Natural History Museum in London, an octopus's brain-to-body ratio is the largest of any invertebrate. The common octopus, a different species, has over 500 million neurons, similar in number to a dog, and over two thirds of them are in its arms and body rather than its central brain. The suckers on a giant Pacific octopus's arms help it grip things and taste them. Each sucker on an octopus's arm may have about 10,000 neurons, or nerve cells. They handle taste and touch.

Giant Pacific octopuses can tell individual people apart. In a 2010 study, eight giant Pacific octopuses were each exposed to two unfamiliar people over two weeks. One person fed them, and the other touched them with a bristly stick. By the end of the study, the octopuses behaved differently toward the two people: a dark eyebar pattern, arm reaching and funnel direction all differed significantly.

A giant Pacific octopus named Pandora opened her first puzzle jar in 15 minutes. Later jars took her about two minutes on average. Aquarium researchers suggest that individual giant Pacific octopuses have different temperaments, which could explain why they handled toys for different lengths of time.

The veined octopus, a relative, carries halves of coconut shell under its body and uses them as portable shelter. Among invertebrates, which are animals without backbones, only octopuses and a few insects are known to use tools, says the Natural History Museum.

A giant Pacific octopus has sharp vision. Giant Pacific octopuses are visual hunters. That means they use their eyes to find food, with a variety of hunting strategies. Cephalopods, including octopuses, appear to be colorblind, except for a few deep-sea species. An octopus's skin has a top layer of pigment organs called chromatophores that make its colors. A giant Pacific octopus can change the color of its skin to blend in. It can also change the texture of its skin, raising bumps to match its surroundings.

A giant Pacific octopus has eight arms. It has three hearts and blue blood. Of its three hearts, two pump blood to the gills and one pumps blood to the rest of the body. The only hard part of its body is its beak, which looks like a parrot's. It can squeeze through a very small space.

The giant Pacific octopus is the largest kind of octopus in the world. As of November 2026, a full-grown one often weighs 50 pounds (23 kg) or more. As of November 2026, the Seattle Aquarium says adults weigh 40 to 100 pounds, with a relaxed tip-to-tip span of 12 to 14 feet. Monterey Bay Aquarium and the Alaska Wildlife Alliance both say the heaviest on record weighed 200 pounds and measured nearly 20 feet across. National Geographic and National Wildlife magazine both report a record of more than 600 pounds and about 30 feet across, a much larger figure than the 200 pounds other sources give.

Giant Pacific octopuses live from southern California north to Alaska and the Bering Sea. They also live across the Pacific to Japan. As of November 2026, reference guides disagree about how deep they live. One says to 750 meters, another to 1,000 meters, and others to 1,500 meters. As of November 2026, a giant Pacific octopus has been seen resting on science equipment on the seafloor at 1,200 meters depth.

A giant Pacific octopus lives in a den, a small hiding place in rocks or caves. Giant Pacific octopuses live alone and are not social animals. Wild giant Pacific octopuses navigate by landmarks and the contour of the seafloor. They find their way back to their dens.

Giant Pacific octopuses are mostly active at night, and they hunt at night. Their food includes crabs, clams, shrimp, scallops, snails and small fish. When it hunts fish, a giant Pacific octopus may use a toxic saliva to paralyze them. Few animals prey on a full-grown giant Pacific octopus. The main ones are large fish and marine mammals such as sea lions.

A giant Pacific octopus lives about 3 to 5 years. A female breeds only once in her life. Giant Pacific octopuses breed near the end of their lives and die not long after. A mother lays her eggs in a den and stays with them, usually not eating, until they hatch. A female lays about 20,000 to 100,000 eggs.

The eggs take roughly 5 months to a year to hatch, depending on the water temperature. A baby is about the size of a grain of rice when it hatches. After hatching, the tiny octopuses drift near the ocean surface as plankton. About one percent of giant Pacific octopus larvae survive their drifting plankton stage.

Words to know

• neurons: nerve cells
• temperaments: personality styles
• chromatophores: color cells
• plankton: drifting life