There are over 2000 species of jellyfish, yet they are largely misunderstood creatures. Floating along the ocean currents, these mindless sea creatures can be found in a surprisingly large array of shapes and sizes.

Jellyfish can range from less than an inch in diameter to the biggest jellyfish reaching over 100 feet long.

If you have a fascination for jellyfish and are interested in some of the largest ones in the world, here’s a list of the 10 biggest jellyfish found in the ocean.

Moon Jellyfish (Aurelia aurita)

Size: The bell of the Moon jellyfish can get as large as 12 inches (30 cm), with tentacles that dangle up to 12 feet
Did you know that: Some moon jellyfish species exhibit bioluminescence

Moon jellyfish have a translucent bell-shaped body with a blueish-white, delicate appearance
Moon jellyfish have a translucent bell-shaped body with a blueish-white, delicate appearance

The Moon jellyfish is one of the most commonly found jellyfish in the ocean and can be found in the majority of the world.

The jelly is well distinguished by its four horseshoe-shaped reproductive organs that can be seen through its translucent body.

Due to their unique appearance, and global abundance, Moon jellyfish are often kept in aquariums.

Blubber Jellyfish (Catostylus mosaicus)

Size: The blubber jellyfish can reach a size of up to 30 centimeters (12 inches) in diameter
Did you know that: Changes in water quality, temperature, and nutrient levels affect blubber jellyfish populations

The blubber jellyfish typically has a rounded, bell-shaped body that can grow up to about 20cm in diameter
The blubber jellyfish typically has a rounded, bell-shaped body that can grow up to about 20cm in diameter

Found in the Indo-pacific Ocean along the coasts of Australia, New Zealand, and Southeast Asia, the Blubber jellyfish is easily distinguished by its bluish appearance.

It is through this blue hue that it gets its common name of the “Blue Blubber jellyfish”.

The Blubber Jellyfish is commonly found in shallow waters, which include bays, estuaries, and lagoons. These jellyfish thrive in warmer waters and therefore remain closer to the coast.

These jellyfish are not lethal to humans, although they can cause irritation on the skin with a painful sting that could lead to shock in younger people. 

As this jelly is abundant, you should remain cautious when in its waters.

Egg Yolk Jellyfish (Phacellophora camtschatica)

Size: Egg Yolk Jellyfish can have a bell size of up to 60 cm (24 inches) in diameter and long tentacles that can reach lengths of up to 6 meters (20 feet)
Did you know that: A gas-filled sac called a pneumatophore allows them to float and stay afloat in the water column

The massive bell of the Phacellophora camtschatica can reach up to 3 feet in diameter, with tentacles trailing over 20 feet behind it
The massive bell of the Phacellophora camtschatica can reach up to 3 feet in diameter, with tentacles trailing over 20 feet behind it

Another large jellyfish that’s found in the northern Pacific Ocean, including the coasts of California, Alaska, and Japan.

The species has a bell-shaped body that looks like an egg yolk floating in egg white. They can reach up to 2 feet (60 cm) with tentacles that drag for several feet behind them.

Egg Yolk Jellyfish are typically found in open water, from the surface down to approximately 650 feet (200 meters), where they can be found in large groups when ocean waters begin to rise in summer.

Purple-Striped Jellyfish (Chrysaora colorata)

Size: Pacific sea nettle can have a bell diameter of up to 30 centimeters (12 inches) and long tentacles that can reach up to 3 meters (10 feet)
Did you know that: Instead of pulsating their bell to swim like other jellyfish, they use rhythmic contractions of their “swimming bell”

Not all jellyfish are dangerous, but some are lethal
Not all jellyfish are dangerous, but some are lethal

The Purple-striped Jellyfish is a beautiful species found in the eastern Pacific Ocean along the coasts of North and South America.

These jellies are commonly found in coastal regions. However, they do make their homes in deeper water when plankton is abundant.

With a bell-shaped body that can reach up to 3 feet in diameter and tentacles that reach up to 10 feet, this jellyfish is not the biggest in the ocean, but it still has some size to show. 

The bell of the jellyfish is mostly translucent with pink stripes on its bell (hence the name).

Pacific Sea Nettle (Chrysaora fuscescens)

Size: The bell can reach up to 2.5 feet (0.8 meters) in diameter, and the tentacles can extend up to 10 feet (3 meters) in length. 
Did you know that: Diet and nutrition can affect the coloration of the jellyfish, sometimes turning it translucent or slightly pink

Sea nettles have long, trailing tentacles that are covered in stinging cells, which they use to capture their prey
Sea nettles have long, trailing tentacles that are covered in stinging cells, which they use to capture their prey

Commonly known as the Pacific sea nettle, this jellyfish can be found in the waters of the eastern Pacific Ocean, ranging from Alaska to California. The Pacific Sea Nettle can often be sighted with brown stripes or spots on its golden-brown colored bell.

These jellyfish are found in both shallow waters near the coast as well as deeper offshore waters. Sighting these jellyfish is best done during the summer when they are most abundant and active.

Black Sea Nettle (Chrysaora achlyos)

Size: Black sea nettle has a bell diameter that can reach up to 3 feet (0.9 meters). Its tentacles can be up to 25 feet (8 meters) long
Did you know that: Their predatory nature helps regulate the populations of other jellyfish species

The dark and ominous-looking Chrysaora achlyos is one of the largest known species of jellyfish
The dark and ominous-looking Chrysaora achlyos is one of the largest known species of jellyfish

Deriving its name from its dark purple to black color. This large jellyfish has a distinctive reddish tint, which makes it easily identifiable.

The Black Sea Nettle can grow tentacles up to 25 feet ( 8 meters) long, with a bell diameter of up to 3 feet (0.9m).

This is primarily a deep sea, eastern Pacific, dwelling jellyfish, although they are found in shallower waters closer to the coasts of California (USA) down to Baja California (Mexico).

Although these jellies are known to stay in deep-sea regions, yet closer to the coast, they have been known to drift in ocean currents as far as the coast of Hawaii.

Arctic Lions Mane Jellyfish (Cyanea capillata arctica)

Size: Arctic Lion’s Mane Jellyfish can grow up to 0.9 meters (3 feet) in diameter and has tentacles that can reach up to 30 meters (100 feet) in length
Did you know that: Arctic lion’s mane jellyfish often exhibit seasonal migration patterns

Found in the cold waters of the Arctic and North Atlantic, the Cyanea capillata arctica can have a bell diameter of up to 3 feet
Found in the cold waters of the Arctic and North Atlantic, the Cyanea capillata arctica can have a bell diameter of up to 3 feet

A subspecies of the Lions Man jellyfish, the Arctic Lions Mane inhabits the icy waters of the Arctic Ocean. 

The Arctic Lions Mane is smaller than its Cyanea capillata cousin, but still comes in at an impressive diameter of 3 feet (0.9 meters) and with 100 feet long tentacles.

These jellies are commonly found drifting along the Bering Sea, the Gulf of Alaska, the Aleutian Islands, and the coast of northern Canada.

It’s believed that due to climate change, the habitat range of these jellyfish is expanding, which will have a variety of positive and negative effects on the region’s ecology.

Giant Jellyfish (Stygiomedusa gigantea)

Size: Giant Jellyfish can have a bell diameter of up to one meter (3.3 feet), and its tentacles can reach up to 9 meters (30 feet) in length
Did you know that: Giant jellyfish sightings are relatively rare thanks to their deep-sea habitat

The Giant jelly is a deep-sea jellyfish that spends most of its time away from the continental shelf. Being deep sea creatures, these jellyfish are not often encountered by humans. 

Favoring depths between 900 and 8000 feet, the Giant jellyfish has been recorded at depths as low as 13,000 feet.

This jellyfish feeds mainly on plankton, small fish, and other jellyfish as it moves through the water column of the waters of the Pacific Ocean, particularly off the coast of California, the Gulf of California, and the western Pacific.

Nomura’s Jellyfish (Nemopilema nomurai)

Size: The diameter of their umbrella can reach up to 2 meters (6.5 feet), and they can weigh up to 220 kilograms (485 pounds)
Did you know that: Due to environmental changes, Nomura’s jellyfish are being found further afield from their original habitats

This massive jellyfish can grow up to 6 feet in diameter and weigh over 400 pounds
This massive jellyfish can grow up to 6 feet in diameter and weigh over 400 pounds

Another cold water jellyfish of the northern hemisphere, the Nomura’s Jellyfish can reach lengths up to 100 feet (30 meters), with a width of 6.5 feet (2 meters).

The Nomura’s jelly inhabits the Pacific Ocean and is usually found floating in East China and the Yellow Sea.

This large jellyfish species has a yellow-brown color similar to the Lion’s Mane jelly. However, it is lighter in complexion.

The Nomura jellyfish was named after the Japanese scientist Dr. Kan’ichi Nomura who was the first to describe the jellyfish.

Lions Mane Jellyfish (Cyanea capillata)

Size: Their main body can grow up to 8 feet (2.4 meters) in diameter, and their tentacles can reach up to 120 feet (36.5 meters) in length
Did you know that: The Lions Mane jellyfish is the largest jellyfish species

With tentacles reaching over 120 feet, the Lion's Mane Jellyfish is the largest known jellyfish in the world
With tentacles reaching over 120 feet, the Lion’s Mane Jellyfish is the largest known jellyfish in the world

Coming in at number one on the list, and by far the largest jellyfish in the world, is the Lions Mane jellyfish. This jellyfish gets its name from its yellow-brown tentacles that look somewhat like the mane of a lion.

The Lion’s Mane Jellyfish inhabits the colder waters of the northern hemisphere, particularly in the Arctic, North Atlantic, and North Pacific oceans, where they commonly dwell in coastal regions.

The largest Lions Mane Jellyfish recorded had a bell size of 8 feet (2.4 meters) in diameter and tentacles 120 feet (36.5 meters) long.

FAQs

What feeds on the biggest jellyfish?

Larger jellyfish have few predators, although some species that feed on them include sea turtles, some species of fish such as sunfish, and some species of seabirds.

What is the size of the largest jellyfish ever recorded?

The largest recorded Lion’s Mane jellyfish had a bell diameter of 7.6 feet (2.3 meters) and tentacles that reached 120 feet (36.5 meters) in length.

Are the largest jellyfish dangerous to humans?

Yes, the largest jellyfish can be dangerous to humans. Their tentacles are covered in stinging cells called nematocysts that can cause painful stings. That said, most of the larger jellyfish species are not life-threatening to humans and, in most cases, won’t require a hospital visit.

What do the largest jellyfish eat?

The largest jellyfish feed on a variety of small organisms, which include small fish, plankton, and other jellyfish.

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