The giant Pacific octopus is not only the largest of its kind but also one of the most intelligent and mysterious creatures in the ocean.
Planet’s Largest Octopus
Officially named Enteroctopus dofleini, the giant Pacific octopus (GPO) lives up to its name. Adults typically measure 2 to 4 meters in length and weigh between 20 and 50 kilograms. The largest recorded specimen reached an astonishing 9.75 meters and weighed 272 kilograms — roughly the size of an adult polar bear with eight arms.
Nine Brains and Three Hearts
This octopus is a recognized genius among invertebrates. It possesses nine brains — one central brain and one in each arm, allowing it to multitask with remarkable precision. Each arm acts semi-independently and is lined with chemical-sensitive suckers that can taste as well as touch.
It also has three hearts: two pump blood to the gills, while the third circulates it through the rest of the body. During active swimming, the central heart temporarily halts to prioritize movement.
Master of the Hunt
The GPO is a stealthy nocturnal predator. Thanks to its chromatophores, it can change color and skin texture instantly, blending into the seafloor. It uses a burst of jet propulsion to surprise prey — grabbing it with powerful arms and injecting a paralyzing venom through its saliva. Its sharp beak and radula (toothed tongue) can crush crab shells and even pierce small sharks.
“A pile of empty shells on the ocean floor often marks the hidden den of a giant Pacific octopus.”
Where It Lives
GPOs inhabit the northern Pacific Ocean — from Japan and Korea to the coasts of Canada, the US, and Mexico. They are found at depths ranging from 5 meters to over 1,000 meters, favoring caves, rocks, and shipwrecks for shelter.
A Tragic Final Mission
These octopuses breed only once in their life. After mating, the female lays tens of thousands of eggs and guards them diligently for up to six months without eating. She gently fans the eggs, protects them from predators, and removes debris — until the hatchlings emerge and she dies, having fulfilled her life’s purpose.
Are They Dangerous to Humans?
Despite their size, giant octopuses are not aggressive toward humans. Like all octopuses, they possess venom, but it is rarely harmful to people. A bite may cause pain or swelling, but with prompt care, it's generally harmless.
Unmatched Intelligence
Experts rank the GPO as the most intelligent invertebrate. It can:
- Open jars and complex latches
- Recognize individual humans
- Solve puzzles and mazes
- Squeeze through openings the size of a coin
- Steal fish from traps in the wild
In aquariums, they are often given toys and problem-solving tasks to stimulate their advanced cognitive abilities.
Is the Species at Risk?
Not yet. The IUCN classifies the GPO as a species of Least Concern, but researchers warn this may change. Ocean pollution, warming waters, reef destruction, and bycatch mortality could threaten its survival in the future.
Quick Profile
- Scientific Name: Enteroctopus dofleini
- Length: 2–4 meters (up to 9.75 meters)
- Weight: 20–50+ kilograms
- Lifespan: 3–5 years
- Habitat: Northern Pacific Ocean, depths up to 1500 meters
- Brains: 9
- Hearts: 3
- Traits: Camouflage, intelligence, nocturnal hunting, powerful beak
The giant Pacific octopus is a mesmerizing creature — a perfect blend of alien elegance, brilliant mind, and oceanic power. It stands not just as the largest octopus in the world, but as one of the most fascinating inhabitants of our blue planet.
