27 Types of Octopus in the Ocean

Unique types of octopus in the ocean

The ocean is filled with all sorts of sea creatures, and among them are many different and fascinating types of octopus. Scientists and marine life enthusiasts are highly hooked on these creatures.

From the tiny Star-Sucker Pygmy Octopus to the large and clever Giant Pacific Octopus, there are many kinds to discover. In this article, we will explore 27 different types of octopuses.

We will highlight what sets each type apart and how they have adapted to their specific ocean homes. We will also share more details like their appearance, size, origin, and preferred habitats. Let’s begin!

27 Types of Octopus Species

1. Algae Octopus

Algae Octopus
Scientific Name:Abdopus aculeatus
Origin:Indonesia, Philippines, and Northern Australian coastlines
Size:Mantle: About 3 inches
Arms: About 10 inches in length
Weight:Not properly documented
Diet:Small crustaceans, portunids, and crabs
Habitat:Sea grass areas with sandy dens and algae-like camouflage
Unique Features:Dubbed “the land octopus”

The Algae Octopus is a fascinating marine creature predominantly found along the coastlines of Indonesia, the Philippines, and Northern Australia. 

Boasting a mantle measuring approximately three inches and arms that can extend up to 10 inches, Algae Octopuses are relatively small creatures. 

Their diet mainly consists of small crustaceans, portunids, and crabs, which shows their predatory nature in their natural habitat. 

Speaking of habitat, they prefer to reside in sea grass areas, where they create sandy dens and utilize their algae-like camouflage to blend seamlessly with their surroundings.

One of the most intriguing aspects of this type of octopus is its nickname, “the land octopus.” This comes from the fact that they are the only octopus species adapted to living on land.

Watch this video to get a glimpse at this type of octopus:

A short glimpse of the wonderful Algae Octopus

2. Argonaut or Paper Nautilus

Argonaut or Paper Nautilus
Scientific Name:Argonauta argo
Origin:Tropical and subtropical oceans worldwide
Size:Eggcase (produced only by females) have a shell up to 12 inches
Arms: Not specified 
Weight:Not properly documented
Diet:Small crustaceans and jellyfish
Habitat:Open ocean, often near the surface
Unique Features:Females produce a thin, paper-like eggcase that they use both for egg-laying and as a buoyant float.

The Argonaut, or Paper Nautilus, is a unique octopus species in tropical and subtropical oceans worldwide.

The female Argonauts are particularly noteworthy. They produce a thin, paper-like eggcase. This eggcase serves two purposes: protecting their eggs and acting as a buoyant float for navigation in open waters. On the other hand, males do not have this eggcase. 

Regarding diets, Argonauts generally feed on small crustaceans and jellyfish. They prefer the open ocean and stay near the surface to utilize their unique floating mechanism effectively.

With their relatively long arms and unique eggcase floaters, Argonauts add to the diverse range of octopus species in the ocean.

3. Atlantic Pygmy Octopus

Atlantic Pygmy Octopus
Scientific Name:Octopus joubini
Origin:Western Atlantic Ocean, primarily around Florida and the Caribbean
Size:Mantle: About 1.5 inches
Arms: About 3 to 6 inches in length
Weight:Not properly documented
Diet:Small crustaceans and bivalves
Habitat:Shallow coastal waters with sandy or muddy bottoms
Unique Features:Known for their intelligence and ability to change color rapidly

Distinguished by remarkable intelligence and rapid color-changing abilities, the Atlantic Pygmy Octopus is a small yet intriguing inhabitant of the Western Atlantic Ocean. 

These creatures predominantly reside in the warm waters surrounding Florida and the Caribbean. They thrive in shallow coastal habitats with sandy or muddy bottoms. 

Size-wise, they are notably petite, with mantles measuring around 1.5 inches and arms extending between 3 and 6 inches

Despite their diminutive size, they are proficient hunters that feed primarily on small crustaceans and bivalves. 

Their ability to swiftly alter their color helps in hunting and serves as an effective means of camouflage. This ability, combined with their size, makes them masters of disguise in their shallow coastal habitats.

4. Atlantic White Spotted Octopus

Atlantic White Spotted Octopus
Scientific Name:Callistoctopus macropus
Origin:Mediterranean Sea and the Eastern Atlantic Ocean
Size:Mantle: Up to 8 inches
Arms: Up to 59 inches
Weight:Not properly documented
Diet:Crustaceans, mollusks, and small fish
Habitat:Rocky and sandy bottoms in coastal waters
Unique Features:Known for their white spots and reddish-brown color

The Atlantic White Spotted Octopus, found in the Mediterranean Sea and the Eastern Atlantic Ocean, sports a mantle that can grow up to 8 inches, while their arms can stretch an impressive 59 inches

Appearance-wise, they display a unique coloration of white spots on a reddish-brown background; however, like many other cephalopods, they can also change their appearance.

This is thanks to special cells in their skin called chromatophores, which can expand or contract to alter colors. They can also adjust their skin’s texture, making it smoother or bumpier for camouflage or communication.

When it comes to habitat, Atlantic White Spotted Octopuses prefer rocky and sandy bottoms in coastal waters. Their diet mainly includes crustaceans, mollusks, and small fish. 

5. Bimac Octopus

Bimac Octopus
Image credit: kaitlinmorgan.8 / Instagram
Scientific Name:Octopus bimaculoides
Origin:Eastern Pacific, primarily off the coast of California
Size:Mantle: Up to 7 inches
Arms: Up to 23 inches in length
Weight:5 to 9 pounds
Diet:Crabs, snails, and small fish
Habitat:Rocky coastal areas and tide pools
Unique Features:Two distinctive blue eye spots (ocelli) on its mantle

The Bimac Octopus is a captivating marine creature that predominantly resides off the coast of California in the Eastern Pacific. 

With mantles that can grow up to 7 inches and arms that can reach lengths up to 23 inches, these octopuses are considered average size. 

They are easily recognized by the two distinctive blue eye spots, known as ocelli, on their mantles, which serve not just for show but also play a role in communication and attracting mates.

Regarding habitat, Bimac Octopuses prefer rocky coastal areas and tide pools, where they hunt for crabs, snails, and small fish. 

Their ability to blend into their surroundings, along with their striking appearance, captivates marine enthusiasts. Another name for this species is “California Two-spot Octopus.”

6. Blanket Octopus

Blanket Octopus
Scientific Name:Tremoctopus violaceus
Origin:Tropical and subtropical oceans worldwide
Size:Females: Up to 72 inches in length (including arms)
Males: About 1 inch
Weight:Females: About 20 pounds
Males: significantly lighter
Diet:Plankton, small crustaceans, and jellyfish
Habitat:Open ocean, often near the surface
Unique Features:Females are much larger than males; females have a “blanket” of webbing between their arms.

The Blanket Octopus makes its home in tropical and subtropical oceans worldwide. One of the most notable traits of this species is the striking difference between the male and female. 

Females grow up to 72 inches in length, including their arms, and weigh approximately 20 pounds. In contrast, males are much smaller, growing only to about 1 inch long and weighing significantly less.

This remarkable sexual dimorphism is a trait it shares with several other marine species.

During one of my diving trips in the Philippines, I was fortunate enough to catch a glimpse of this beautiful sea creature up close.

I knew I was looking at a female Blanket Octopus due to the webbing between its arms that looked like a smooth, flowing blanket. 

Additionally, here’s a rare footage of a blanket octopus spotted off the coast of Romblon, Philippines:

Rare 'rainbow' blanket octopuses caught on camera in the Philippines | USA TODAY

7. Greater Blue-Ringed Octopus

Greater Blue Ringed Octopus
Scientific Name:Hapalochlaena lunulata
Origin:Pacific and Indian Oceans, primarily around Australia
Size:Mantle: About 2 inches
Arms: Up to 7 inches in length
Weight:Weighs only a few ounces
Diet:Small crustaceans like crabs and shrimp
Habitat:Tidal pools and coral reefs
Unique Features:They have blue rings that appear when threatened.

Native to the Pacific and Indian Oceans and particularly found around Australia, the Greater Blue-Ringed Octopus stands out as a tiny and unique octopus. 

They have a mantle that measures approximately 2 inches and arms that can extend up to 7 inches. As expected from their very small size, these creatures only weigh a few ounces

They are known for their diet, which mainly consists of small crustaceans, with a preference for crabs and shrimp. In terms of habitat, they choose to live in tidal pools and coral reefs. 

The vibrant blue ring is the most famous feature of these octopuses. When they feel threatened, they intensify their rings, creating a sharp contrast against their usually well-camouflaged body.

This sudden burst of bright color can surprise predators, allowing the octopus an opportunity to escape. These octopuses also possess a highly deadly venom.

8. Capricorn Octopus

Capricorn Octopus
Scientific Name:Callistoctopus alphaeus
Origin:Western Pacific, primarily around Australia and New Guinea
Size:Mantle: About 3 inches
Weight:Not properly documented
Diet:Primarily crustaceans and small fish
Habitat:Coral reefs and rocky substrates in coastal waters
Unique Features:Recognized by its reddish-brown color with white spots and lines

The Capricorn Octopus is usually found in the Western Pacific, especially along the coasts of Australia and New Guinea. 

These octopuses mainly feed on crustaceans and small fish, showcasing their hunting skills in their natural habitats. 

They navigate skillfully through coral reefs and rocky substrates in coastal waters. They frequent areas that provide them with plenty of food and protection from predators.

The reddish-brown color of these octopuses, highlighted by white spots and lines, makes them easily recognizable. 

Despite their fascinating nature and appearance, details about their size and weight remain unknown, as they haven’t been studied as much as other octopus species. However, some sources claim its mantle can grow up to 3 inches.

9. Caribbean Reef Octopus

Caribbean Reef Octopus
Scientific Name:Octopus briareus
Origin:Caribbean Sea,
Size:Mantle: Around 6 inches
Arms: Up to 36 inches in length
Weight:Not properly documented
Diet:Crustaceans, mollusks, and small fish
Habitat:Coral reefs and rocky areas in shallow coastal waters
Unique Features:Recognized by its long, slender arms and webbing that extends almost to the tip of the arms

Standing out with its long, slender arms, the Caribbean Reef Octopus can reach up to 36 inches in arm length, and its mantles are roughly 6 inches wide. 

These octopuses are commonly found in the Caribbean Sea, especially around Florida, the Bahamas, and the Yucatán Peninsula. 

They make their homes in coral reefs and rocky parts of shallow coastal waters, where they find most of their prey. Their diet is quite varied, consisting of crustaceans, mollusks, and small fish. 

One of the most striking features of Caribbean Reef Octopuses is the extensive webbing that stretches almost to the tips of their arms.

This webbing not only contributes to their distinctive look but also aids in their mobility and hunting capabilities. This allows them to create a net to trap prey. 

10. Cirrothauma manga

Cirrothauma magna octopus
Scientific Name:Cirrothauma magna
Origin:Deep-sea regions worldwide
Size:Not properly documented
Weight:Not properly documented
Diet:Deep-sea crustaceans and other small organisms
Habitat:Deep-sea, often at depths of several thousand feet
Unique Features:They have large eyes that are likely light-sensitive; they have a distinctive cirri on their arms

The Cirrothauma magna is a special type of octopus that lives deep in the ocean worldwide. This octopus is usually found thousands of feet down the surface.

These octopuses have very big eyes, which are likely highly light-sensitive. This adaptation is crucial for the octopus, as it helps them navigate their dark underwater world.

What makes them stand out are the special features on their arms. These help them blend in with their surroundings and protect themselves from predators. 

However, it is important to note that these features are not cirri, which are appendages found in other types of cephalopods, such as cuttlefish.

Fun Fact: The Cirrothauma magna doesn’t have a common name. This is likely because they are hard to find and not seen very often.

11. Coconut Octopus

Coconut Octopus
Scientific Name:Amphioctopus marginatus
Origin:Western Pacific Ocean
Size:Mantle: Approximately 3 inches
Arms: Up to 14 inches in length
Weight:Not properly documented
Diet:Small crustaceans, bivalves, and small fish
Habitat:Sandy and muddy bottoms in shallow waters
Unique Features:Known for its behavior of using coconut shells and other debris as shelter

Making its home in the Western Pacific Ocean, the Coconut Octopus is a small octopus species, with a full-grown mantle of approximately 3 inches and arms stretching up to 14 inches

These octopuses have a diverse diet, mostly eating small shellfish, clams, and little fish. They like to live in shallow waters, particularly where the sea floor is sandy or muddy.

What sets these octopuses apart is their unique use of coconut shells and other debris as shelters. They carry these items around, using them for protection when needed.

This behavior, along with their ability to walk on two legs and create defensive barriers, shows how they have adapted to thrive in their surroundings.

These are just some traits that make the Coconut Octopus a fascinating species for marine enthusiasts worldwide.

12. Common Octopus

Common Octopus
Scientific Name:Octopus vulgaris
Origin:Found the Mediterranean Sea, the Atlantic Ocean, and parts of the Indian Ocean
Size:Mantle: Up to 9 inches
Arms: Up to 36 inches in length
Weight:6 to 22 pounds
Diet:Crabs, lobsters, and bivalves
Habitat:Rocky and sandy bottoms, often in coastal waters 
Unique Features:High intelligence; ability to change their skin color and texture

The Common Octopus is a species with a wide distribution, inhabiting the Mediterranean Sea, the Atlantic Ocean, and certain areas of the Indian Ocean. 

These octopuses are relatively large, boasting mantles that can grow up to 9 inches and arms stretching up to 36 inches.

Their ability to alter their skin color and texture is a standout feature. This helps them hide from predators and catch their favorite food: crabs, lobsters, and bivalves. 

You can find Common Octopuses in places with rocks and sand on the ocean floor, usually near the coast, but they can also live in deeper waters, up to 650 feet.

A notable feature of the Common Octopus is its high level of intelligence compared to other octopus species. It has been observed using tools, solving complex problems, and even escaping from enclosures. 

13. Day Octopus

Day Octopus
Scientific Name:Octopus cyanea
Origin:Tropical waters of the Indian and Pacific Oceans
Size:Mantle: About 6 inches
Arms: Up to 36 inches in length
Weight:6 to 14 pounds
Diet:Crustaceans, mollusks, and small fish
Habitat:Coral reefs and rocky substrates
Unique Features:Active during the day, which is unusual for octopuses

Hailing from the warm Indian and Pacific Oceans, such as Hawaii, the Red Sea, and Australia, the Day Octopus is a medium-sized octopus with a mantle about 6 inches long and arms reaching up to 36 inches.

They eat crustaceans, mollusks, and small fish, and they like living near coral reefs and on rocky bottoms. 

The Day Octopus stands out because it is active during the day, unlike most octopuses that prefer the night. This daytime activity is rare and gives the Day Octopus its name.

Day Octopuses have to be very careful because being active in the daylight can expose them to predators. But, it also means they can hunt and look for food when their prey is out and about, which could help their catch.

Fortunately, their fondness for the day makes them relatively easier to study and observe.

14. Dumbo Octopus

Dumbo Octopus
Scientific Name:Grimpoteuthis bathynectes
Origin:Deep-sea regions worldwide
Size:Mantle: About 8 inches
Arms: exact length can vary
Weight:Not commonly specified due to deep-sea habitat, but they are relatively small and lightweight
Diet:Worms, bivalves, copepods, and other small prey
Habitat:Deep-sea, typically at depths of 1,300 to 13,000 feet
Unique Features:Characterized by the ear-like fins protruding from the top of their head, resembling the ears of Disney’s Dumbo

The Dumbo Octopus stands out in the ocean because of how it looks. You can find these octopuses deep under the sea worldwide. 

Size-wise, they usually have a mantle that’s about 8 to 12 inches. Their arms are small and light, which works well for living deep in the ocean. 

These octopuses are seen between 1,300 and 13,000 feet under the water. Meanwhile, when it comes to diet, they eat worms, bivalves, and tiny crustaceans called copepods.

What sets the Dumbo Octopus apart is its remarkable ear-like fins located on top of its head. Because of the size, shape, and placement of these fins, they resemble the ears of Disney’s Dumbo, hence the name.

These fins are not just for show, though, as they play a crucial role in helping these creatures navigate. The Dumbo Octopus mainly use their fins to swim, hover above the seafloor, and move through the water column. 

15. Flapjack Octopus

Flapjack Octopus
Image credit: thatwasalmostfun / Instagram
Scientific Name:Opisthoteuthis californiana
Origin:Eastern Pacific, particularly off the coast of California
Size:Mantle: Up to 8 inches
Weight:Not properly documented
Diet:Small crustaceans and benthic organisms
Habitat:Deep-sea environments, often at depths of 1,000 to 2,500 feet
Unique Features:Known for its flat and round body shape, resembling a pancake

Inhabiting the deep waters of the Eastern Pacific near the coasts of California is the Flapjack Octopus. These octopuses are well-known for their unique shape — a flat, round body resembling a pancake. 

This unusual shape is thanks to their soft, gelatinous bodies, which are different from the muscular bodies of other cephalopods.

What’s interesting about them is how they move through the water. They use their webbed arms to gracefully glide and swim, showing off their unique shape and soft texture. 

Size-wise, these creatures are on the smaller side, with their mantles measuring approximately 2 inches. They mainly eat small crustaceans and creatures that live on the ocean floor. 

These unique octopus species live deep down, between 1,000 and 2,500 feet. This is where they’ve adapted to extreme pressure and low light.

16. Giant Pacific Octopus

Giant Pacific Octopus
Scientific Name:Enteroctopus dofleini
Origin:North Pacific, from California up to Alaska and across to Japan
Size:Mantle: At least 24 inches
Arms: Up to 190 inches in length
Weight:Up to 150 pounds
Diet:Crabs, clams, fish, and other marine organisms
Habitat:Cold, coastal waters, often in rocky areas with plenty of hiding spots
Unique Features:One of the largest octopus species, known for its intelligence and ability to open jars and solve puzzles in captivity

The Giant Pacific Octopus is a remarkable creature known to inhabit the North Pacific, which includes the waters of California up to Alaska and extending across to Japan. 

These octopuses mainly eat crabs, clams, fish, and other sea creatures. They like coastal waters and rocky areas where they can hide. 

What makes them special, though, aside from their incredible size, is how smart they are. They can solve complex problems, handle objects carefully, and even open jars to get to food. This shows just how clever and skilled they are.

Scientists are still learning about their ability to learn and interact as they show new signs of intelligence. For instance, when kept in tanks, they use tools and act in ways that show they are aware and can adapt.

Speaking of their intelligence, just recently, I stumbled upon a study from 2010 that found that these octopuses can tell the difference between different people. The study also showed that they act differently if a person is feeding them or poking them with a stick. 

This finding highlights the importance of mindfulness during interactions with these octopuses. It also gave insights into how their ability to recognize people can alter their behavior.

On a related note, here’s an informative video showing how smart these octopus species are:

Genius Octopus Can Open Jars | Octopus In My House | BBC Earth

17. Glass Octopus

Glass Octopus
Image credit: karmasearch / Instagram
Scientific Name:Vitreledonella richardi
Origin:Deep-sea habitats worldwide
Size:Arms: Up to 16 inches in length
Weight:Not properly documented
Diet:Small fish and other marine organisms
Habitat:Pelagic waters, often found at depths of 1,000 to 2,000 feet
Unique Features:Almost completely transparent body, with visible internal organs

A unique creature in the underwater world, the Glass Octopus has a body that is almost completely transparent. 

These octopuses live deep, mainly in open waters at depths between 1,000 and 2,000 feet. Their arms can grow as long as 16 inches, and they eat small fish and various marine organisms.

Despite looking fragile, Glass Octopuses are well-suited to their deep-sea homes. Their transparent bodies serve as a form of camouflage and help them hide from predators in the ocean. 

This clear appearance comes from a lack of pigment in their skin, making everything but their digestive system, optic nerves, and eyes invisible.

18. Ghost Octopus

Ghost Octopus
Image credit: oceanspecies / Instagram
Scientific Name:Stauroteuthis syrtensis
Origin:North Atlantic Ocean
Size:Mantle: Up to 4 inches
Arms: Up to 8 inches
Weight:Not properly documented
Diet:Small crustaceans and other marine organisms
Habitat:Deep-sea environments, often found at depths of 1,500 to 4,500 feet
Unique Features:Known for its bioluminescent capabilities

The Ghost Octopus stands out as a unique species living in the deep-sea regions of the North Atlantic Ocean. These octopuses have mantles that can grow up to 4 inches and arms stretching 8 inches

What sets them apart is their ability to produce light. The octopus can emit a blue-green light from its suckers for short periods, around five minutes at a time. 

This light display serves various purposes, from luring prey to scaring off predators. Interestingly, the males and females of this species have differently shaped suckers.

Ghost octopuses mainly feed on small crustaceans and other sea creatures. They choose to live in deep waters, ranging from 1,500 to 4,500 feet.

While their weight is not properly documented, their distinct features and choice of habitat still make them one of the most unique octopus species out there.

19. Lilliput Longarm Octopus

Lilliput Longarm Octopus
Scientific Name:Macrotritopus defilippi
Origin:Atlantic Ocean
Size:Mantle: Up to 3.5 inches
Weight:Not properly documented
Diet:Small crustaceans and possibly small fish
Habitat:Sandy or muddy bottoms
Unique Features:Long, slender arms; not much is known about this species

You can spot the Lilliput Longarm Octopus in the vast Atlantic Ocean. These small sea creatures sport a mantle reaching up to 3.5 inches. They also boast long, slender arms.

These octopuses prefer to hide away on sandy or muddy seabeds, where they hunt small crustaceans and tiny fish while blending in with their surroundings.

What makes Lilliput Longarm Octopuses stand out is their ability to disguise as flatfish, such as soles or flounders. 

Interestingly, they don’t just copy their appearance; they move like them too. These octopuses line up their body and arms to mimic the flatfish’s unique way of swimming.

This trick is a clever way to steer away predators by pretending to be a less appealing meal. 

20. Mimic Octopus

Mimic Octopus
Scientific Name:Thaumoctopus mimicus
Origin:Indo-Pacific region
Size:Mantle: Up to 2 inches
Arms: Up to 24 inches
Weight:Not properly documented
Diet:Small fish, worms, and crustaceans
Habitat:Sandy or muddy bottoms in shallow waters
Unique Features:Ability to mimic the appearance and behaviors of other marine animals, such as lionfish, flatfish, and sea snakes

The Mimic Octopus is another unique octopus species in the Indo-Pacific waters. They are named after their unparalleled skill in impersonating other marine animals. 

They can change their appearance and behavior to look and act like other sea creatures that are dangerous or unappealing to predators, such as lionfish, flatfish, and sea snakes. 

This ability acts as their defense mechanism. It keeps threats at bay and allows them to roam freely. 

Regarding size, these small octopuses sport a mantle barely reaching 2 inches and arms stretching up to 24 inches.

They make their homes in shallow waters, settling on sandy or muddy bottoms, and their diet consists mainly of small fish, worms, and crustaceans.

21. Mosaic Octopus

Mosaic Octopus
Scientific Name:Abdopus abaculus
Origin:Western Pacific region, particularly around Indonesia and the Philippines
Size:Mantle: Approximately 1.3 inches 
Weight:Less than an ounce
Diet:Likely small crustaceans, mollusks, and possibly small fish
Habitat:Warm, shallow waters, often around coral reefs and rocky areas
Unique Features:Named from a distinctive pattern or coloration on its skin, resembling a mosaic

The Mosaic Octopus stands out as a unique and small creature native to the Western Pacific region, especially thriving in areas around Indonesia and the Philippines. 

These octopuses are among the smaller species, with a mantle size of about 1.3 inches and a weight of less than an ounce. They have a diet that mainly includes small crustaceans, mollusks, and small fish.

One thing that distinguishes Mosaic Octopuses from other species is their distinctive skin pattern or coloration, resembling a mosaic, which is also where they get their name. 

Not a lot is known about the traits of these unique octopus species. However, M. D. Norman and M. J. Sweeney first described it in a 1997 study, where they were initially called Octopus abaculus.

22. Sandbird Octopus

Sandbird Octopus
Scientific Name:Amphioctopus aegina
Origin:Indo-Pacific region
Size:Mantle: Up to 3 inches
Arms: Not properly documented
Weight:About 0.8 pounds
Diet:Feeds on small crustaceans, fish, and bivalves
Habitat:Sandy and muddy substrates
Unique Features:Known for its ability to burrow and create shelters in the sand

A small to medium creature, the Sandbird Octopus has a mantle reaching 4 inches long and can be found in the Indo-West Pacific region. They inhabit sandy and muddy areas and have an impressive ability to burrow and create shelters.

You can easily spot them by their special colors: they have big, light patches and dark marks on their upper bodies and a light cream line down the middle of their backs. 

Sandbird Octopuses are typically solitary creatures, with peak activity occurring during dawn and dusk, displaying a crepuscular behavior.

In their mating rituals, male octopuses show off to get the females’ attention. Once they’ve mated, males and females don’t live much longer, a common pattern in the life of cephalopods.

23. Seven-Arm Octopus

Seven Arm Octopus
Image credit: matteo_visconti_uw / Instagram
Scientific Name:Haliphron atlanticus
Origin:Found in oceans worldwide, particularly in deep-sea habitats
Size:Up to 130 inches in length, including arms
Weight:Can weigh up to 165 pounds
Diet:Feeds on jellyfish and other gelatinous prey
Habitat:Deep-sea environments ranging from 3,200 to 14,500 feet in depth
Unique Features:Despite its name, it has eight arms, but one is significantly smaller and often hidden.

The Seven-Arm Octopus stands out as a unique dweller of the deep sea. These octopuses are large, reaching up to 130 inches in length, including their arms, and can weigh as much as 165 pounds

Despite their name, they have eight arms. However, one of these arms is much smaller and usually stays hidden, giving them their distinctive moniker. 

This hidden arm is not just a smaller version of the others; it has a unique structure and function, acting as their hectocotylus. The male uses this specialized arm to transfer sperm packets to the female.

This adaptation is a testament to the octopus’s ability to evolve and thrive in its habitat.

It’s worth noting that Seven-Arm Octopuses are not the only octopus species with a specialized reproductive arm. Still, they are unique in having one that is significantly smaller and usually hidden. 

24. Southern Blue-Ringed Octopus

Southern Blue Ringed Octopus
Scientific Name:Hapalochlaena maculosa
Origin:Coastal waters of Australia
Size:Mantle: About 2 inches
Arms: Up to 5 inches in length
Weight:Less than a pound
Diet:Small crustaceans like crabs and shrimp
Habitat:Tidal pools and coral reefs
Unique Features:Known for its bright blue rings that appear when threatened; one of the world’s most venomous marine animals

A captivating species in Australia’s coastal waters, the Southern Blue-Ringed Octopus is renowned for its appearance and potent venom. 

These species set themselves apart with bright blue rings that become especially vivid when threatened. This warning sign aids in fending off potential predators. 

These octopuses are small, with a mantle measuring approximately 2 inches and arms reaching up to 5 inches. Nonetheless, they are among the world’s most venomous marine animals. 

They reside in tidal pools and coral reefs where they hunt for prey, usually small crustaceans like crabs and shrimp. 

Note that this species is different from the Greater Blue-Ringed Octopus, another venomous octopus that has similar bright blue rings but is found in a broader range of the Pacific and Indian Oceans. 

25. Southern Keeled Octopus

Southern Keeled Octopus
Image credit: connectedtoportphillip / Instagram
Scientific Name:Octopus berrima
Origin:Coastal waters of Southern Australia
Size:Mantle: About 3 inches
Arms: Up to 10 inches in length
Weight:Not properly documented
Diet:Crustaceans, small fish, and bivalves
Habitat:Rocky reefs and seagrass beds
Unique Features:Has a keel-like structure on its arms

Next up on our list is the Southern Keeled Octopus, a unique octopus species hailing from the coastal waters of Southern Australia. 

In terms of size, this octopus is on the smaller side, with a mantle approximately 3 inches wide and arms stretching to just about 10 inches.

They have a particular preference for crustaceans, small fish, and bivalves, which they actively hunt in rocky reefs and seagrass beds. 

These octopuses are easily distinguishable by the keel-like structure on their arms. This is a feature not commonly found in other octopus species.

Southern Keeled Octopuses were also the subject of a recent study titled “Statolith chemistry: a new tool to understand the ecology and provenance of octopus.” 

In the study, scientists determine where the octopuses come from by observing statoliths, which are small parts inside their body that help them balance,

The findings suggested that statoliths could tell where the octopus lived with 85% accuracy. This helps keep fishing sustainable and helps scientists learn more about how octopuses move around.

26. Star-Sucker Pygmy Octopus

Star Sucker Pygmy Octopus
Scientific Name:Octopus wolfi
Origin:Indo-Pacific region
Size:Mantle: Less than an inch
Arms: About an inch
Weight:Not properly documented
Diet:Small crustaceans and plankton
Habitat:Coral reefs and shallow waters
Unique Features:One of the smallest known octopus species

The Star-Sucker Pygmy Octopus is a tiny marvel in the ocean, mainly found in the Indo-Pacific region. This species is one of the smallest octopuses, with its mantle measuring less than an inch and its arms extending up to an inch

For a better reference on how incredibly tiny these octopuses are, they are shorter than a paperclip or about the size of a small coin.

These octopuses live in coral reefs and shallow waters, where they feed on small crustaceans and plankton. Despite their small size, they are crucial in the marine food chain.

Their exact weight isn’t well documented, but it is safe to assume they are quite light due to their size. 

27. Larger Pacific Striped Octopus

Larger Pacific Striped Octopus display while female watches.
Scientific Name:LPSO (Larger Pacific Striped Octopus), not yet formally described with a scientific name
Origin:Eastern Pacific, from Nicaragua to Colombia
Size:Mantle: Up to 2 inches
Arms: Up to 20 inches in length
Weight:Not properly documented
Diet:Shrimps, crabs, clams, and snails
Habitat:Sandy bottoms and seagrass beds near coral reefs
Unique Features:Displays striking color patterns, exhibits “mate-guarding,” and shows unusual social behavior towards humans

Wrapping up our list is the Larger Pacific Striped Octopus, a marine creature known for its large size and striking colors. Unlike most octopuses that like to be alone, this one often hangs out with others of its kind. 

You can find these octopuses in the warm waters on the Pacific side of Nicaragua to Colombia. Regarding habitat, they are often seen on the ocean floor, especially on sandy buttons and seagrass beds. 

These intriguing octopuses exhibit behaviors that set them apart from their more solitary relatives. 

In 2015, research found that these octopuses even share their homes with their partners. This extended “mate-guarding” is not usually seen in other octopus species.

Additionally, the study highlighted that female Larger Pacific Striped Octopuses are unique in their ability to lay eggs over an extended period, which can last for as long as six months.

That’s also quite rare because most octopuses usually die soon after they give birth. Moreover, they still eat and hang out with their mates during this time. 

Frequently Asked Questions

Unique octopus on corals

What Is the Most Interesting Type of Octopus?

Many people find the Mimic Octopus the most fascinating type of octopus. This unique creature can change its shape and behavior to resemble other marine animals, such as lionfish, flatfish, and sea snakes. 

What Is the Friendliest Octopus?

The Larger Pacific Striped Octopus is known for its unusual social behavior, which is rare among octopuses. This species tends to live in groups and has even been known to interact playfully with humans. 

However, it is important to note that this species is different from the Giant Pacific Octopus despite the similarities in their names.

What Is the Rarest Octopus?

The Glass Octopus, with its nearly invisible body and delicate structure, is considered one of the rarest octopus species. Due to its deep-sea habitat, it is rarely seen by humans. 

Its ghost-like appearance and the mystery of its deep-sea life make it one of the most fascinating and rare octopuses.

What Is the Largest Type of Octopus?

The Giant Pacific Octopus holds the record as the largest octopus species. It can have an arm span of approximately 190 inches and weigh more than 100 pounds.

What Is the Smallest Type of Octopus?

The title of the smallest octopus goes to the Star-Sucker Pygmy Octopus (Octopus wolfi), with an average size of just a few inches. 

This octopus can be as big as a large coin. The main part of its body is only about an inch wide, and its arms are about an inch long. You’ll usually find them squeezed into small spaces in coral reefs.

So, what is your favorite kind of octopus? Share your thoughts about these unique octopus species by leaving a comment below!

Leave a Comment

You may also like