There are more than three hundred species of octopus. Each has eight limbs and a soft body, making it possible for them to do things that are impossible for many other animals.
They’re highly intelligent with a complex nervous system, outstanding eyesight, and a hard and pointy beak for feeding. They can also swim quite efficiently, even at very deep depths.
In general, octopi dwell along coastlines, hunting for their favorite foods. They’re usually venomous, though most species are not known to have venom lethal to humans. They can even alter their coloring, using their body for camouflage against predators.
Octopuses are a diverse collection of animals of various sizes and coloring. The most miniature octopus, the Octopus Wolfi, is about an inch long and weighs a single gram.
But what about the biggest octopus? Ranked from one to ten, the largest octopus in the world are an interesting bunch!
Table of Contents
This monstrous-sized octopus is the biggest globally, with an overall length over fifteen feet or more. They typically weigh about 150 pounds, but the largest can be heavier and longer.
The most enormous giant Pacific octopus ever measured was thirty feet long and tipped the scales at about 600 pounds.
These giants are awe-inspiring to behold even when in captivity, but they are relatively short-lived, with a lifespan of only three to five years.
They subsist on shrimp, snails, scallops, lobster, fish, abalone, clams, crabs, other octopuses, or even small sharks.
They’re not nocturnal, but they seem to do most of their hunting at night, perhaps because their keen eyesight gives them an advantage over other predators and their prey.
Though discerning their numbers is quite difficult, due to their short life span and reclusive habits, the population is relatively stable, and giant Pacific octopuses are observable throughout their range.
The seven-arm octopus is the second-largest octopus in the world, coming in with a maximum weight of about 165 pounds, with a length of around eleven feet. Males and females are typically of similar size.
The name of this species of octopus is a bit of a misnomer, as they do, in fact, have all eight appendages. Though now understood to be their ‘missing’ eighth leg, some still refer to this species as the septopus due to their seven-legged appearance.
The reason for the discrepancy and confusion around its name is that male specimens have one leg positioned in a coil underneath their right eye. But, due to their gelatinous, thick tissue folds, it’s hard to notice unless it’s uncoiled.
This coiled leg is only unfurled to fertilize a female’s eggs during mating. Interestingly, despite being known as an Atlantic-dweller, there have been some sightings of the seven-arm octopus in waters of the South Pacific Ocean.
Interestingly, one of the largest octopuses ever discovered in the wild was a seven-arm caught in a fishing net dragged along the sea bed at a depth of nearly 1,000 feet.
The frilled giant Pacific octopus is related to, but distinct from, the standard giant Pacific octopus. Observers have long wondered about the origin of this octopus, with its distinguishing feature, an odd-looking frill or ledge. The nets of shrimp fishers often catch these octopuses, as they go after the same catch.
Recent DNA-based research has shown evidence that these creatures are a ‘genetic sister’ to the Giant pacific octopus, but that their lifestyles and habit selection may have given rise to its corporal differences.
They are also quite large, and scientists consider them the third biggest octopus species globally, slightly smaller than seven-arm and giant Pacific octopuses.
Since their discovery in 2017 is so recent, scientists have yet to assign them a unique official Latin name. They are distinguishable from the giant Pacific species by a lack of longitudinal folds along their mantle and a frill or flap on their midline.
They also have two distinct and separate white dots near the front of their bodies, while the true giant octopus has either one spot or none.
Their range includes areas along the Pacific rim coastline, from Japan to California and north to Alaska and the Bering Sea.
Primarily found in the waters around New Zealand and South Australia, the Maori octopus is the fourth largest.
Also referred to as the New Zealand octopus, they can be anywhere from about 40-inches long to about six and a half feet, and they have a reputation for being extremely aggressive when compared to their other octopus kin.
That ferocity is often displayed when a female lays a clutch of eggs. Numbering up to 7,000, she will lay her eggs for up to two weeks.
She will remain nearby for two months, defending them from predators and using her limbs to fan a steady supply of fresh, oxygenated water over them during that period.
During this phase, she will not consume any food, and similarly to many species of octopuses, she will perish soon after her eggs have hatched.
The species of Enteroctopus aren’t quite as large as the world’s four largest, but they can be up to six feet in length.
They may weigh as much as thirty pounds, though twenty-five pounds is average. They prey on certain species of hagfish and crab, but they prefer the deep ocean swimming portunid crab for the bulk of their meals.
Observers have also seen them eat birds. Their coloring ranges from a rusty red to much brighter tones.
They range throughout the temperate areas of the Pacific, from the waters off Alaska south to the southern California coast and across the ocean to Japan and the Aleutian Islands. They usually live for between three and five years.
This species of octopus lives in much of the world’s waters, with a habitat ranging from the Mediterranean Sea to most of the Atlantic Ocean and beyond.
They’re also relatively large, with weights between six-and-a-half pounds and typical lengths ranging from one to three feet. They are among the most widely studied and abundant of all octopi.
Some of these studies have focused on their well-developed and seemingly advanced brains and nervous systems.
Some common octopuses have even proven the species’ ability to problem solve, performing advanced tasks like opening jars.
Though widely dispersed worldwide, these octopuses tend to prefer the rocky areas near coastlines. Their diet isn’t very picky, but their preferred food sources include mollusks, crayfish, and crabs.
Mimic octopuses have some impressive camouflage skills that surpass the body-changing capabilities of other species.
They are exceedingly adept at blending into their surroundings, matching their appearance to other animals and the nearby seascapes. They can become nearly invisible, though they are also typically fairly large.
They are adept enough to use their camouflage to imitate the coloring and shape of poisonous or territorial animals and fauna, making them appear dangerous to their predators.
They have small horns near each eye, and when not actively camouflaging, they have a pale brown or beige coloring.
Male mimicus octopuses are lighter than their female counterparts, weighing only five or six pounds. Females can way up to twenty pounds.
On average, this species of octopus is around two feet long, but some individuals can be even bigger. They’re found in the areas of the Pacific, stretching from the Great Barrier Reef to the Red Sea and the Gulf of Thailand.
Their long, slender tentacles are ideal for foraging in narrow crevices, and they seemingly prefer sandy, murky waters up to a depth of around forty-five feet.
The yellow octopus, named for its pale yellow appearance, is one of the more mysterious species of octopus in the world.
It’s very reclusive and rarely recovered in fishing nets or scientific expeditions off the coast of its principal territory, the waters around New Zealand. A relatively large yellow octopus was once found to weigh eleven pounds and was well over four-and-a-half feet long.
Since they’re so rarely found, it’s difficult to even gauge their average size or the overall health of the species or even to put an accurate count on how many there are in the world.
But, they are seemingly quite abundant, though hermetic. Scientists know this because they are often found in the jaws of New Zealand sea lions in the Auckland Islands. The stomachs of beached whales often contain the yellow octopus’s indigestible beak.
The southern red octopus is usually just under nine pounds and can be about three-and-a-half feet long. That makes them relatively large.
But this species of giant octopus isn’t quite as big as some of the others on the list. However, they are easy to identify due to their oar-shaped papillae and distinctive red coloring.
They’re found along the coastlines of Argentina in the Atlantic ocean and Chile in the Pacific, where they are the most common species of octopus found.
They’re also called the Patagonian red octopus in English, the Pulpo colorado (colored-red octopus) in Argentina, and Pulpo del Sur in Chile (octopus of the south).
Commercial fishing targets these octopuses for human consumption, and they are also a favorite food source for other sea-going predators, like spiny dogfish and some species of sea lion.
The fins of a dumbo octopus are quite large and floppy, much like the oversized ears of the famous cartoon elephant of the same name.
On average, these octopuses are typically less than twelve inches long, but some specimens have been larger. The largest on record was almost six feet long and weighed nearly thirteen pounds.
You’re probably out of luck if you’re hoping to see one of these octopuses in the wild. They prefer to live at depths below 13,000 feet, making sightings extraordinarily rare.
That may be why they have few natural predators and don’t have the defensive ink sac that most species of octopus do. But, they do occasionally fall prey to deep-diving carnivores like sharks, dolphins, and tuna.
Since the vastness of the deep ocean is immense and often lonely, the females of this species carry eggs in various stages of development. This way, if they ever come across a suitable male partner for mating, they can do so.
Plus, they can store the sperm collected from a male for an extended period, enabling them to wait for suitable water conditions or swim to a more favorable location for laying their eggs.