Octopuses are among the most fascinating creatures in the ocean.
Up to 300 species of these bizarre eight-limbed creatures have been identified in oceans worldwide.
They are brilliant animals known to exhibit a wide range of fascinating behaviors, including camouflage, mimicry, and other advanced behaviors.
Some octopus species can also grow to impressive sizes.
The biggest of them all is the giant Pacific octopus.
Some of its closest relatives within the Enteroctopus genus are big as well, which is why they’re collectively called giant octopuses.
In this article, we’ll list some of the biggest octopus species found in various locations all over the world and discuss some of their most interesting attributes.
15. Ruby Octopus
| Common name | Ruby octopus (East Pacific red octopus) |
| Scientific Name | Octopus rubescens |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 30–40 centimeters (12–16 inches) |
| Weight | 400 grams (14 ounces) |
| Depth | 300 meters (980 feet) |
| Location | East Pacific Ocean |
The ruby octopus is the preferred common name for the East Pacific red octopus (Octopus rubescens).
As the common name suggests, this octopus species is a deep brick red but can also vary its color to brown, white, or a mottled mixture of these colors to camouflage or blend in with its environment.
The ruby octopus inhabits the East Pacific Ocean and is the most common octopus species in the shallow waters of the west coast of North America.
The ruby octopus has an average arm length of about 30 to 40 centimeters (12 to 16 inches), and adults that weigh up to 400 grams have been discovered.
14. California Two-Spot Octopus
| Common name | California two-spot octopus |
| Scientific Name | Octopus bimaculoides |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 58 centimeters (23 inches) |
| Weight | 1.5 kilograms (3.3 pounds) |
| Depth | 20 meters (65 feet) |
| Location | Pacific Ocean |
The California two-spot octopus (Octopus bimaculoides) is an octopus species commonly found in parts of the Pacific Ocean, especially off the coast of California.
It is also commonly referred to as the “bimac.”
One of the most notable traits distinguishing this octopus species is the circular blue eyespot on each side of its head.
The eyespots positioned under the actual eyes of this octopus give it the appearance of a different animal with bigger eyes when it swims in the water, which is helpful for evading predators.
The bimac is typically found at depths of about 20 meters (65 feet), where it hides in rocky reefs.
13. Mimic Octopus
| Common name | Mimic octopus |
| Scientific Name | Thaumoctopus mimicus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 60 centimeters (2 feet) |
| Weight | 2.3–9.1 kilograms (5–20 pounds) |
| Depth | 15 meters (49 feet) |
| Location | Indo-Pacific Region (especially Indonesia) |
The mimic octopus (Thaumoctopus mimicus) is found in the waters of the Indo-Pacific Ocean.
As the name implies, the mimic octopus is known for its impressive ability to mimic other animals to evade predators and catch prey.
While other animals (including many species of octopus) are known for their impressive camouflage, the mimic octopus takes this ability to another level.
It doesn’t just disguise itself by blending with its background; Thaumoctopus mimicus can take on the appearance of several animals, especially some of the most poisonous sea creatures.
It does this by varying the position of its tentacles and changing its colors to take on the form and appearance of the animal it is trying to mimic.
The mimic octopus is not very big, growing to a maximum length of about 60 centimeters (2 feet).
12. Caribbean Reef Octopus
| Common name | Caribbean reef octopus |
| Scientific Name | Octopus briareus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 0.6 meters (1.9 feet) |
| Weight | 1.5 kilograms (3.3 pounds) |
| Depth | 3–20 meters (9–65 feet) |
| Location | Central and South America |
The Caribbean reef octopus (Octopus briareus) lives in the coral reef environments off the coast of Central and South America.
It is an elusive species that loves to stay hidden in rocky liars that are difficult to locate.
It changes its lair frequently, moving from place to place in search of food and mates.
The arms of the Caribbean reef octopus vary in length and diameter, but the average length is about 60 centimeters long.
This octopus weighs about 1.5 kilograms (3.3 pounds) on average.
It’s difficult to determine the actual appearance of the Caribbean reef octopus because it changes both the color and texture of its skin frequently in order to blend in with its environment.
11. Day Octopus
| Common name | Day octopus |
| Scientific Name | Octopus cyanea |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 0.8 meters (2.6 feet) |
| Weight | 0.067–6.5 kilograms (0.1–14.3 pounds) |
| Depth | 22 meters (72 feet) |
| Location | Indo-Pacific region |
The day octopus is also commonly referred to as the “big blue octopus” because of its size.
It has an average arm length of about 0.8 meters and can grow to a maximum weight of up to 6.5 kilograms (14 pounds).
This octopus is found in the Pacific and Indian Oceans and is most common off the islands of Hawaii and the coast of East Africa.
As the common name suggests, the day octopus is one of the few octopus species known to be more active during the day than at night.
It forages during the day but returns frequently to its den, usually in a rock crevice or any other hidden location.
The day octopus has a relatively short lifespan of about 12 to 15 months but grows quickly within this period.
10. Southern Red Octopus
| Common name | Southern red octopus |
| Scientific Name | Enteroctopus megalocyathus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 1–1.3 meters (3.3–4.2 feet) |
| Weight | 4–8 kilograms (8.8–17.6 pounds) |
| Depth | 220 meters (720 feet) |
| Location | South America |
The southern red octopus (Enteroctopus megalocyathus) is also known as the Patagonian red octopus because it is native to South America.
It is typically found off the coast of Chile and Argentina.
This medium-sized octopus is the smallest species in the Enteroctopus genus of giant octopuses.
It has an average weight of about four kilograms, but some individuals have been known to grow as big as eight kilograms.
The average arm length of this octopus is about 1 to 1.3 meters.
As the name suggests, the natural color of the southern red octopus is red or reddish brown.
However, it may also change its skin color to blend in with the sand or rock surface where it lives.
9. Common Octopus
| Common name | Common octopus |
| Scientific Name | Octopus vulgaris |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 1 meter (3.3 feet) |
| Weight | 9 kilograms (20 pounds) |
| Depth | 200 meters (660 feet) |
| Location | Worldwide |
The common octopus (Octopus vulgaris) is one of the best-known species.
It is found in tropical and temperate waters worldwide, where it mostly lives in shallow depths of about 200 meters (660 feet).
The common octopus has an average arm length of about one meter (3.3 feet) and weighs roughly nine kilograms (20 pounds).
The common octopus is considered the most intelligent invertebrate.
The nervous system of this octopus consists of up to 500 million neurons, comparable to that of a dog.
The common octopus is also famous for its impressive evasive techniques, which it uses to escape from predators.
It can change its color to blend in with its surroundings or release a cloud of black ink to obscure the attacker’s view before jetting away quickly.
8. Yellow Octopus
| Common name | Yellow octopus |
| Scientific Name | Enteroctopus zealandicus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 1.4 meters (4.6 feet) |
| Weight | 4.9 kilograms (11 pounds) |
| Depth | 300–522 meters (984–1,712 feet) |
| Location | New Zealand |
The yellow octopus (Enteroctopus zealandicus) is a species native to New Zealand.
It is found in the deep waters of the Pacific Ocean, mainly at an average depth of about 300 to 522 meters.
Despite being abundant in this region, very little is known about the yellow octopus because of its elusive nature.
The yellow-to-orange color of this octopus species allows it to blend in with its surroundings.
This octopus belongs to the Enteroctopus genus, along with some of the biggest octopus species.
However, it has an average length of about 1.4 meters, making it one of this group’s smallest members.
7. Dumbo Octopus
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| Common name | Dumbo Octopus |
| Scientific Name | Grimpoteuthis |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 1.8 meters (5.9 feet) |
| Weight | N/A |
| Depth | 4,000 meters (13,000 feet) |
| Location | Worldwide |
The dumbo octopus (Grimpoteuthis) is named after Dumbo, the Disney elephant character famous for its big ears.
This is due to the prominent ear-like fins of this octopus that resemble the ears of Dumbo, the elephant.
The octopus uses these fins to propel itself through the water.
The name applies to about 17 species of octopuses within the Grimpoteuthis genus.
Members of this genus have a worldwide distribution.
They’re typically found at depths of up to 13,000 feet, which makes them the deepest-dwelling octopus species.
Sightings of this octopus are extremely rare.
Most dumbo octopuses are about 20 to 30 centimeters (8 to 12 inches) long.
However, the largest individual ever found was up to 1.8 meters (5.9 feet).
6. Southern Giant Octopus
| Common name | Southern giant octopus |
| Scientific Name | Enteroctopus magnificus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 1.8 meters (5.9 feet) |
| Weight | 11.4 kilograms (25 pounds) |
| Depth | 1,000 meters (3,200 feet) |
| Location | South Atlantic Ocean (Namibia and South Africa) |
The southern giant octopus (Enteroctopus magnificus) is a large octopus found in the waters of the South Atlantic Ocean off the coast of Namibia and South Africa.
This octopus typically lives at shallow depths of about 1,000 meters where its typical prey, such as the portunid crab and cape hagfish, are quite abundant.
It belongs to the genus Enteroctopus, which means it is closely related to other giant octopuses, such as the giant Pacific octopus.
Enteroctopus magnificus grows to an average length of about 1.8 meters and weighs roughly 11.4 kilograms (25 pounds) on average.
5. Blanket Octopus
| Common name | Blanket octopus |
| Scientific Name | Tremoctopus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 2 meters (6.6 feet) |
| Weight | 2.7–4.5 kilograms (6–10 pounds) |
| Depth | 250 meters (820 feet) |
| Location | Subtropical and tropical oceans worldwide |
While the male blanket octopus (Tremoctopus) does not qualify for this list (it’s only about one inch), the female blanket octopus is one of the largest octopus species in the world.
Females can grow to a length of up to two meters (6.6 feet).
The difference in size between male and female members of this genus is one of the most extreme cases of sexual dimorphism in any animal.
They are called blanket octopuses because the arms of the adult females are connected by a long transparent web that looks like a blanket.
The blanket octopus is known to rip off the tentacles of the venomous Portuguese man o’ war, which it then uses to defend itself against predators.
4. Maori Octopus
| Common name | Maori Octopus |
| Scientific Name | Macroctopus maorum |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 3 meters (9.8 feet) |
| Weight | 12 kilograms (26 pounds) |
| Depth | 550 m (1800 feet) |
| Location | New Zealand and Southern Australia |
The Maori octopus (Macroctopus maorum) is a giant octopus species found in the waters off the coast of New Zealand and Australia.
It is one of the largest octopus species found in these countries.
They live in the shallow waters of the southern Indian Ocean, where they’re mainly found in shallow rocky reefs and kelp forests at a depth of about 550 meters.
The Maori octopus is a robust octopus with long muscular arms.
The arms of this octopus are of different lengths, but the longest and broadest of them are up to three meters (9.8 feet) long.
The Maori octopus is an aggressive species, and cannibalism is quite common among them.
They have a very short lifespan, and females usually die off after their eggs hatch.
3. Frilled Giant Pacific Octopus
| Common name | Frilled giant Pacific Octopus |
| Scientific Name | N/A |
| Classification | N/A |
| Arm span | 4.5 meters (16 feet) |
| Weight | 70 kilograms (150 pounds) |
| Depth | 2,000 meters (6,600 feet) |
| Location | North Pacific Ocean |
The frilled giant Pacific octopus is a close relative of the giant Pacific octopus.
Both species are found in the same waters and look similar in their overall appearance.
However, it is slightly smaller than the actual giant Pacific octopus, with an average arm span of about 16 feet.
Frilled giant Pacific octopuses have raised fleshy bumps on the edge of their skin, which run through their entire body length and give their appendages a frilly appearance.
The frilled giant Pacific octopus was only identified as a separate species in 2017 based on both visual and DNA evidence.
It is yet to be fully described or officially named.
2. Seven-Arm Octopus
| Common name | Seven-arm octopus |
| Scientific Name | Haliphron atlanticus |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 3.5 meters (11 feet) |
| Weight | 75 kilograms (165 pounds) |
| Depth | 914 meters (3,000 feet) |
| Location | Atlantic and Pacific Ocean |
The seven-arm octopus (Haliphron atlanticus) is the largest octopus in the world in terms of mass.
It weighs 75 kilograms (165 pounds), and the largest individual found so far has an average length of 3.5 meters (11 feet).
It is also known as the blob octopus because its body comprises thick gelatinous tissues.
Octopuses have eight arms, and that’s true even for the “seven-arm” octopus.
It is called the seven-arm octopus because one of its arms has been modified into a coiled sac (known as the hectocotylus), useful for egg fertilization.
The coiled arm is located underneath the octopus’ right eye and is often overlooked when counting its arms.
1. Giant Pacific Octopus
| Common name | Giant Pacific octopus |
| Scientific Name | Enteroctopus dofleini |
| Classification | Cephalopoda, Octopoda, Octopodidae |
| Arm span | 6 meters (20 feet) |
| Weight | 50 kilograms (110 pounds) |
| Depth | 2,000 meters (6,600 feet) |
| Location | North Pacific Ocean |
The giant Pacific octopus (Enteroctopus dofleini) holds the record for the largest octopus species in the world.
It is also known as the North Pacific giant octopus because it is mainly found in the cold, oxygen-rich water of the North Pacific Ocean, from Japan to Alaska to California.
This deep-sea species can weigh up to 50 kilograms (110 pounds) and have an average arm span of up to six meters (20 feet).
The suckers on the tentacles of this monstrous octopus have an average diameter of about 6.4 centimeters (2.5 inches), and each one can support a weight of 16 kilograms (35 pounds).
The giant Pacific octopus is found at depths of about 2,000 meters (6,600 feet) below sea level, where it preys on shrimps, crabs, lobsters, squids, and other octopuses.
Sources:
- https://en.wikipedia.org/wiki/Enteroctopus
- https://en.wikipedia.org/wiki/Seven-arm_octopus
- https://octonation.com/maori-octopus-facts/
- https://en.wikipedia.org/wiki/Common_octopus
- https://niwa.co.nz/news/critteroftheweek/187
- https://en.wikipedia.org/wiki/Blanket_octopus
- https://en.wikipedia.org/wiki/Caribbean_reef_octopus
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