Skip to Content

12 Giant Jellyfish You Won’t Believe Exist

12 Giant Jellyfish You Won’t Believe Exist

Jellyfish have always captured human imagination with their ethereal beauty and mysterious nature. Floating gracefully through the ocean’s depths, these fascinating creatures come in a variety of sizes, colors, and forms.

Among them, some jellyfish grow to extraordinary sizes, becoming giants of the marine world.

Today I’ll tell you about some of the largest jellyfish species found across the globe, delving into their unique characteristics and habitats.

1. Lion’s Mane Jellyfish

Lion's Mane Jellyfish
© Reddit

The Lion’s Mane Jellyfish is truly a spectacle in the marine world. Growing up to 120 feet long, its tentacles are longer than a blue whale. This jellyfish calls the Arctic and North Atlantic Oceans its home, thriving in the cold waters where it drifts with the currents.

Its vibrant, reddish-brown bell can grow up to eight feet in diameter. Such size makes it the largest known species of jellyfish on Earth.

Despite its intimidating appearance, the Lion’s Mane Jellyfish feeds mainly on small fish, zooplankton, and other jellyfish. Its tentacles are equipped with numerous stinging cells called nematocysts, which it uses to capture prey.

However, these stings are mild and mostly harmless to humans, causing only minor skin irritation.

The Lion’s Mane Jellyfish plays a vital role in its ecosystem, providing food for larger marine animals like sea turtles and sunfish.

Its presence indicates a healthy marine environment, as it thrives in nutrient-rich waters. Observing these majestic creatures in their natural habitat is a breathtaking experience, reminding us of the ocean’s wonders.

2. Nomura’s Jellyfish

Nomura's Jellyfish
© Daily Mail

Nomura’s Jellyfish is another marine giant, primarily found in the waters of the Sea of Japan. With a bell diameter that can reach up to 6.6 feet and a weight of over 440 pounds, it is one of the largest jellyfish species known to humankind.

Its sheer size can be both awe-inspiring and intimidating, especially when encountered by fishermen.

This jellyfish is characterized by its translucent, pinkish-brown bell and long, frilled tentacles that can extend several feet.

Nomura’s Jellyfish experiences population booms, often known as blooms, which can impact local fisheries. During these blooms, they become a significant concern for the fishing industry, as their presence can damage fishing equipment and reduce fish stocks.

Despite these challenges, Nomura’s Jellyfish is a fascinating subject of study. Researchers are keen to understand its life cycle and ecological impact further.

This species highlights the delicate balance within marine ecosystems and the need for sustainable environmental practices to maintain that balance.

3. Stygiomedusa Gigantea

Stygiomedusa Gigantea
© YouTube

The Stygiomedusa Gigantea, often referred to as the giant phantom jellyfish, is a rare and elusive species. It inhabits the deep ocean, often found at depths exceeding 3,300 feet.

Due to its remote habitat, sightings of this jellyfish are infrequent, making it a subject of intrigue among marine biologists.

This jellyfish boasts a bell that can measure over three feet wide, with tentacles extending up to 20 feet. Its dark red coloration helps it blend into the deep ocean environment, providing it some camouflage from predators.

Despite its size, the Stygiomedusa Gigantea moves gracefully through the water, its tentacles trailing elegantly behind.

The feeding habits of this deep-sea giant remain largely a mystery. However, it is believed to prey on small fish and plankton, using its tentacles to ensnare them.

As a deep-sea dweller, the Stygiomedusa Gigantea represents the unexplored mysteries of the ocean, a reminder of how much there is still to learn about the underwater world.

4. Black Sea Nettle

Black Sea Nettle
© YouTube

The Black Sea Nettle is a strikingly beautiful jellyfish that inhabits the coastal waters of the Eastern Pacific Ocean, particularly around California.

It is recognized by its distinctive dark purple bell, which can grow up to three feet in diameter. The contrast between its deep-colored bell and translucent tentacles makes it a captivating sight.

This jellyfish’s tentacles can stretch over 20 feet long, equipped with stinging cells to capture prey such as small fish and zooplankton.

Although its sting can be painful to humans, it is not considered dangerous. The Black Sea Nettle is often seen during the late summer and early fall when it follows the warm water currents.

Intriguingly, the scientists first described the Black Sea Nettle in 1997, which highlights how much of the ocean’s fauna remains to be discovered and understood.

5. Purple Striped Jelly

Purple Striped Jelly
© Wikipedia

The Purple Striped Jelly, also known as Chrysaora colorata, is renowned for its striking appearance. Found primarily in the waters of Monterey Bay, California, this jellyfish is easily identifiable by the vivid purple lines that adorn its bell.

The bell can grow up to three feet in diameter, making it a prominent feature in the marine landscape.

This species uses its long, slender tentacles to capture prey, including small fish and plankton. The tentacles, which can extend several feet beyond its bell, are armed with nematocysts that deliver a mild sting to humans.

Despite its size and stinging capability, the Purple Striped Jelly is a graceful swimmer, moving with the ocean currents.

The presence of the Purple Striped Jelly in coastal waters is often an indicator of the ocean’s health. It thrives in nutrient-rich environments, which underscores the importance of maintaining ecological balance.

This jellyfish not only adds to the aesthetic beauty of the marine world but also plays a crucial role in the oceanic food web.

6. Australian Box Jellyfish

Australian Box Jellyfish
© VS Battles Wiki – Fandom

The Australian Box Jellyfish is infamous for its potent venom, considered one of the most dangerous in the marine world. Native to the coastal waters of Northern Australia, including the Great Barrier Reef, this jellyfish is a master predator despite its seemingly delicate appearance.

Its cube-shaped bell can grow up to nearly one foot in diameter, but what it lacks in size, it makes up for in lethality.

The tentacles, extending up to 10 feet long, are laden with venomous cells capable of delivering a painful sting that can be fatal to humans.

This jellyfish’s translucent body makes it difficult to spot in the water, adding to its menacing reputation.

Despite its dangerous nature, the Australian Box Jellyfish plays a vital role in controlling fish populations, showcasing the complex interactions within marine ecosystems.

Caution and respect for this jellyfish’s power are advised for those venturing into its habitat, highlighting the need for awareness and education about marine life.

7. Sea Nettle

Sea Nettle
© Monterey Bay Aquarium

The Sea Nettle is a common yet captivating jellyfish found along the Atlantic coast of the United States, particularly in the Chesapeake Bay.

It is known for its golden-brown bell, which can reach sizes of up to one foot in diameter. The long, graceful tentacles trailing behind can extend several feet, equipped to capture a variety of prey.

Though its sting is mild, it can cause discomfort to swimmers, making it a frequent encounter during beach outings. The Sea Nettle feeds on small fish, crustaceans, and plankton, using its tentacles to ensnare these creatures efficiently.

Its presence serves as a reminder of the vibrant marine life along the coast.

In terms of ecological significance, the Sea Nettle plays a crucial role in the food chain, providing nourishment for larger fish and sea turtles.

It is also a subject of interest for marine researchers studying the dynamics of jellyfish populations and their impact on coastal ecosystems.

8. Cannonball Jellyfish

Cannonball Jellyfish
© Flickr

The Cannonball Jellyfish, aptly named for its spherical, cannonball-like bell, is a prevalent sight in the warm waters of the Gulf of Mexico and the southeastern coast of the United States.

It is a relatively small jellyfish, with a bell diameter of up to ten inches, but it travels in large swarms, creating an impressive spectacle.

This jellyfish is characterized by its white bell with brown or reddish bands, and short, stubby tentacles. Unlike many other jellyfish, the Cannonball Jellyfish has a mild sting that poses little threat to humans, making it a more approachable member of the jellyfish family.

It primarily feeds on zooplankton, playing a role in the marine ecosystem as both predator and prey.

Beyond its ecological role, the Cannonball Jellyfish is also harvested for culinary uses in some cultures, where it is considered a delicacy.

This dual importance underscores the diverse ways in which jellyfish impact both marine environments and human societies. Its presence in the ocean is a testament to the adaptability and diversity of jellyfish species.

9. Barrel Jellyfish

Barrel Jellyfish
© Oceanographic Magazine

The Barrel Jellyfish is a gentle giant of the ocean, commonly found in the coastal waters of the United Kingdom. Its massive, translucent bell can grow up to 3.3 feet in diameter, making it one of the largest jellyfish in European waters.

Despite its size, it is harmless to humans, with a sting that is considered mild and typically non-threatening.

This jellyfish feeds on plankton, using its multitude of tentacles to capture its tiny prey. During the warmer months, the Barrel Jellyfish often washes up on beaches, creating a stunning sight for beachgoers. Its presence is a natural phenomenon, reflecting changes in ocean conditions and currents.

The Barrel Jellyfish serves as an important food source for marine animals such as leatherback turtles. It also attracts attention for its sheer size and beauty, contributing to the biodiversity of coastal ecosystems.

10. Japanese Sea Nettle

Japanese Sea Nettle
© Ocean Info

The Japanese Sea Nettle is a vibrant and captivating jellyfish found in the waters of the Pacific Ocean, particularly around Japan. Its striking orange bell, which can grow up to two feet in diameter, contrasts beautifully with its long, flowing white tentacles.

This color combination makes it one of the most visually stunning jellyfish species.

This jellyfish uses its lengthy tentacles to capture prey such as small fish and zooplankton. Although its sting is mild to humans, it is effective in immobilizing its prey.

The Japanese Sea Nettle is often seen in large groups, creating a mesmerizing underwater display.

In addition to its ecological role, the Japanese Sea Nettle is a popular exhibit in aquariums around the world, admired for its beauty and elegance.

This jellyfish serves as both a subject of scientific study and a source of fascination for the public, emphasizing the wonder and diversity of ocean life.

11. Pacific Sea Nettle

Pacific Sea Nettle
© Vic High Marine Biology

The Pacific Sea Nettle is a stunning jellyfish species that graces the waters of the North Pacific Ocean. Its golden-brown bell, which can grow up to two feet in diameter, is complemented by long, spiraling tentacles that extend several feet.

This jellyfish is both a predator and a prey, playing a crucial role in the marine food web.

The tentacles of the Pacific Sea Nettle are armed with stinging cells that capture prey such as small fish and plankton.

While its sting can be uncomfortable for humans, it is not considered dangerous. This jellyfish is often found in large swarms, creating a breathtaking sight for divers and ocean enthusiasts.

Beyond its beauty, the Pacific Sea Nettle is a subject of interest for researchers studying jellyfish behavior and population dynamics.

Its presence in the ocean provides valuable insights into marine ecosystems, highlighting the intricate relationships between different oceanic species.

12. Moon Jellyfish

Moon Jellyfish
© Wikipedia

The Moon Jellyfish is an enchanting and widespread jellyfish species, known for its gentle, moon-like appearance. Its translucent bell, which can grow up to 15 inches in diameter, is easily recognizable, featuring four distinct horseshoe-shaped gonads at its center.

This jellyfish is commonly found in shallow coastal waters around the world.

Despite its delicate look, the Moon Jellyfish is a resilient species, capable of adapting to various environmental conditions.

Its diet consists mainly of small fish and plankton, which it captures using its short, fine tentacles. Although its sting is harmless to humans, it is effective in securing its prey.

The Moon Jellyfish is a popular subject in marine education and aquariums, admired for its simple beauty and fascinating biology.

Its presence in the ocean is a reminder of the diversity and adaptability of marine life, offering insights into the balance of oceanic ecosystems. This jellyfish truly embodies the serene and mysterious allure of the underwater world.