17 Types of Jellyfish: From Dangerous Stingers to Harmless Drifters

Delve into the captivating world of 17 different types of jellyfish species. From graceful moon jellies to fearsome box jellyfish, we reveal the mysterious characteristics that make these creatures truly fascinating.

Box Jellyfish
(Chironex fleckeri)

Box Jellyfish at night
Behold the Box Jellyfish, an elegant and venomous beauty.

Chironex fleckeri, holds the title of being the largest of the box jellyfish. With a body size that can reach up to one foot in diameter, it commands attention in the waters it inhabits. Its distinguishing feature lies in its thick, bootlace-like tentacles that can stretch up to an impressive length of 10 feet. These long tentacles are armed with extremely venomous cells called nematocysts, making encounters with this species potentially fatal, unless, of course, you are a leatherback sea turtle.

Scientific Name Chironex fleckeri
Common Names Australian Box Jelly, Box Jelly, Box Fish
Natural Habitat Coastal waters of the Pacific and Indian Oceans
Size Length - up to 10 feet (3 m), Bell size - up to 1 foot (30 cm) in diameter
Venomous Rating High

Moon Jellyfish
(Aurelia aurita)

Two Moon Jellyfish floating against black background
Floating delicately, the Moon Jellyfish illuminates the ocean with its ethereal glow.

Moon Jellyfish, scientifically known as Aurelia aurita, are ethereal creatures that gracefully glide through the ocean. With their translucent and bell-shaped bodies, they resemble delicate, floating moons in the water. These jellyfish are frequently encountered in coastal regions globally, and one can often spot sizable gatherings while snorkeling in Maui, Hawaii. Don't let its gentle appearance fool you—while its sting is generally harmless to humans, its presence in large numbers can cause ecological imbalances with population explosions.

Scientific Name Aurelia aurita
Common Names Moon Jellies, Saucer Jellyfish
Natural Habitat Oceans worldwide
Size Length - up to 16 inches (40 cm), Bell size - up to 12 inches (30 cm) in diameter
Venomous Rating Low

Sea Nettle
(Chrysaora fuscescens)

Sea Nettle Jellyfish with extended tenticles
The Sea Nettle, a graceful swimmer with its trailing tentacles, glides through the sea.

The Sea Nettle is renowned for its vibrant and graceful appearance, with long, trailing tentacles and a translucent bell adorned with beautiful red, orange, or brown hues. Its long, flowing tentacles and vibrant coloration make it a true spectacle. Beware, though, for its sting can cause a painful reaction in humans, earning it a moderate venomous rating.

Scientific Name Chrysaora fuscescens
Common Names Pacific Sea Nettle, West Coast Sea Nettle
Natural Habitat Coastal waters of the Pacific Ocean
Size Length - up to 4 feet (1 to 1.2 m), Bell size - up to 8 inches (20 cm) in diameter
Venomous Rating Moderate

Portuguese Man-of-War
(Physalia physalis)

Portuguese Man-of-War Jellyfish breaching ocean surface
An imposing presence, the Portuguese Man-of-War sails across the ocean, armed with venomous tentacles.

Get ready to encounter one of the ocean's most intriguing creatures, the Portuguese Man-of-War. Despite its name, this marine hydrozoan is not a true jellyfish but rather a colony of specialized organisms called zooids working together as a single entity. Its unique sail-like structure and venomous tentacles make it a formidable presence in the open seas.

Scientific Name Physalia physalis
Common Names Bluebottle, Floating Terror
Natural Habitat Tropical and subtropical waters worldwide
Size Length - up to 165 feet (50 m), Bell size - up to 12 inches (30 cm) long
Venomous Rating High

Upside-Down Jellyfish
(Cassiopea spp.)

Upside-Down Jellyfish on black background
The Upside-Down Jellyfish rests peacefully on the seafloor, defying convention with its unique posture.

Prepare to witness a jellyfish that defies gravity—the Upside-Down Jellyfish. Unlike their drifting counterparts, these jellies prefer to settle on the seafloor, often inverting themselves and forming clusters that resemble soft coral. This unique behavior, coupled with its symbiotic relationship with photosynthetic algae, sets it apart from other jellyfish species.

Scientific Name Cassiopea spp.
Common Names Upside-Down Sea Jelly, Mangrove Jellyfish
Natural Habitat Shallow, warm coastal waters worldwide
Size Length - up to 12 inches (30 cm), Bell size - up to 7 inches (18 cm) in diameter
Venomous Rating Non-Venomous

Comb Jelly

Comb Jelly close up photo
Intricate rows of cilia adorn the Comb Jelly, creating a mesmerizing display of bioluminescence.

Despite its jelly-like appearance, the Comb Jelly is not a jellyfish but belongs to the phylum Ctenophora. Unlike jellyfish, comb jellies do not possess stinging cells. Instead, they capture prey using specialized adhesive cells called colloblasts. These cells secrete a sticky substance that ensnares small marine organisms, which the comb jellies then consume.

Scientific Name Ctenophora
Common Names Comb Jellyfish, Sea Walnut
Natural Habitat Oceans worldwide
Size Length - up to 8 inches (20 cm), Bell size - up to 10 inches (25 cm) in diameter
Venomous Rating Non-Venomous

Cannonball Jellyfish
(Stomolophus meleagris)

Cannonball Jellyfish photo at night
The Cannonball Jellyfish, a gentle giant of the sea, floats gracefully with its spherical shape.

Named for its round and compact shape resembling a cannonball, a gentle giant of the jellyfish world, this species stands out from its counterparts. With a smooth and firm bell, the Cannonball Jellyfish lacks the long tentacles typically associated with other jellyfish species. Instead, it possesses short, stubby arms that surround its mouth. While its sting is typically mild, it's still advisable to exercise caution when encountering them.

Scientific Name Stomolophus meleagris
Common Names Cannonball Jelly, Cabbage Head Jellyfish
Natural Habitat Atlantic and Gulf of Mexico coastal waters
Size Length - up to 8 inches (20 cm), Bell size - up to 10 inches (25 cm) in diameter
Venomous Rating Low

Flower Hat Jellyfish
(Olindias formosa)

Night photo of a Flower Hat Jellyfish
Adorned with petals of tentacles, the Flower Hat Jellyfish captivates with its vibrant beauty.

This jellyfish earns its name from the vibrant, flower-like pattern on top of its bell, which resembles a decorative hat. The Flower Hat Jellyfish boasts a translucent bell with delicate, frilly edges, adding to its graceful appearance. Its tentacles, adorned with stinging cells, hang beneath the bell and serve as a means to capture prey. While the Flower Hat Jellyfish is not considered highly venomous to humans, contact with its tentacles can still result in moderate skin irritation.

Scientific Name Olindias formosa
Common Names Flower Hat Jelly, Crown Jellyfish
Natural Habitat Coastal waters near Japan
Size Length - up to several feet, Bell size - up to 4 inches (10 cm) in diameter
Venomous Rating Moderate

Mushroom Jellyfish
(Rhopilema verrilli)

School of Mushroom Jellyfish floating in deep ocean
Astonishing in its umbrella-like shape, the Mushroom Jellyfish moves with serene grace through the water.

This jellyfish gets its name from its unique umbrella-shaped bell, which resembles the cap of a mushroom. The Mushroom Jellyfish showcases a translucent appearance with delicate oral arms that extend from the center of its bell. Its tentacles, armed with stinging cells, trail below, capturing prey and defending against potential threats. While its venomous rating is generally considered low, caution should still be exercised to avoid direct contact with its tentacles.

Scientific Name Rhopilema verrilli
Common Names Mushroom Jelly, Flower Hat Jellyfish
Natural Habitat Indo-Pacific region
Size Length - up to several feet, Bell size - up to 10 inches (25 cm) in diameter
Venomous Rating Moderate

Irukandji Jellyfish
(Carukia barnesi)

Irukandji Jellyfish showing its long tenticles
The Irukandji Jellyfish, small yet potent, holds the power to induce the dreaded Irukandji syndrome.

Prepare to be amazed and alarmed by the Irukandji Jellyfish. Despite its small size, this jellyfish packs a punch with its venomous sting, which can cause Irukandji syndrome—an intense and potentially life-threatening reaction in humans. Found in the waters of Australia, encountering this jellyfish is not for the faint of heart. It is important to note that encounters with the Irukandji Jellyfish are rare, and prompt medical attention should be sought if stung.

Scientific Name Carukia barnesi
Common Names Irukandji, Carukia Jellyfish
Natural Habitat Australian coastal waters
Size Length - up to 1 inch (2.5 cm), Bell size - very small, less than 1 inch (2.5 cm) in diameter
Venomous Rating High

Sea Wasp
(Chironex yamaguchii)

Sea Wasp Jellyfish on black background
Beware the Sea Wasp, one of the world's most venomous jellyfish, lurking in the Pacific Ocean.

Beware the Sea Wasp, for it is one of the most venomous jellyfish in the world. With its translucent bell and long, tentacle-like appendages, this creature strikes fear into the hearts of swimmers. Found in the waters of the Pacific Ocean, encounters with this jellyfish can be extremely dangerous. A single encounter with the Sea Wasp can result in excruciating pain, skin welts, and even cardiac arrest in severe cases.

Scientific Name Chironex yamaguchii
Common Names Viper Jellyfish, Hub Jellyfish
Natural Habitat Coastal waters of the Pacific Ocean
Size Length - up to 10 feet (3 m), Bell size - up to 1 foot (30 cm) in diameter
Venomous Rating High

Fire Jellyfish
(Mastigias papua)

Group of Fire Jellyfish
Illuminating the depths with its fiery glow, the Fire Jellyfish adds a touch of magic to the ocean.

The Fire Jellyfish showcases a translucent bell adorned with numerous frilly oral arms, giving it a fiery and ethereal appearance. What sets it apart from other jellyfish species is its ability to photosynthesize. Inside its tissues, it hosts symbiotic algae called zooxanthellae, which convert sunlight into energy through photosynthesis. This remarkable adaptation gives the Fire Jellyfish its vibrant coloration, often ranging from orange to reddish-brown.

Scientific Name Mastigias papua
Common Names Fire Jellyfish, Papua Jellyfish
Natural Habitat Tropical waters of the Pacific Ocean
Size Length - up to several inches, Bell size - up to 6 inches (15 cm) in diameter.
Venomous Rating Low

Lion's Mane Jellyfish
(Cyanea capillata)

Colorful Lion's Mane Jellyfish photo on black background
The majestic Lion's Mane Jellyfish, with its flowing tentacles, commands attention in the cold waters.

Named after its striking resemblance to a lion's mane, this jellyfish is renowned for its immense size and beautiful appearance. The Lion's Mane Jellyfish holds the title of the largest known jellyfish species and boasts a bell that can grow up to several feet in diameter, with tentacle which can extend over 100 feet long. Its tentacles are lined with stinging cells, capable of delivering a powerful sting to its prey or to unsuspecting swimmers who come into contact with them.

Scientific Name Cyanea capillata
Common Names Lion's Mane Jellyfish, Giant Jellyfish
Natural Habitat Cold waters of the northern hemisphere
Size Length - over 100 feet (30 m), Bell size - up to 7 feet or 2 m) in diameter
Venomous Rating Moderate

Box-within-a-Box Jellyfish
(Tamoya haplonema)

Box-within-a-Box Jellyfish propelling itself in horizontal position
Discover the enigmatic Box-within-a-Box Jellyfish, an intriguing species with a hidden surprise.

This jellyfish stands out due to its distinctive bell structure, which appears as if it has a smaller box-like bell nestled within a larger one. The Box-within-a-Box Jellyfish showcases a transparent bell with intricate patterns and delicate tentacles hanging below. While its venomous rating is considered moderate, encounters with this jellyfish should be approached with caution.

Scientific Name Tamoya haplonema
Common Names Box-within-a-Box Jellyfish, Cube Jellyfish
Natural Habitat Warm coastal waters
Size Length - up to 8 inches (20 cm), Bell size - up to 4 inches (10 cm) in diameter
Venomous Rating Moderate

Sea Snake Jellyfish
(Chrysaora quinquecirrha)

Sea Snake Jellyfish in horizontal position
The Sea Snake Jellyfish, with its ribbon-like tentacles, glides through the Atlantic waters.

Known for its graceful and flowing tentacles, the Sea Nettle is a captivating sight in the water. With its elongated, ribbon-like tentacles and translucent bell, this species is a mesmerizing sight. Found in the Atlantic Ocean, its sting is relatively mild, earning it a low venomous rating.

Scientific Name Chrysaora quinquecirrha
Common Names Sea Snake Jellyfish, Atlantic Sea Nettle
Natural Habitat Atlantic coastal waters
Size Length - tentacles can extend several feet, Bell size - up to 12 inches (30 cm) in diameter
Venomous Rating Low

Immortal Jellyfish
(Turritopsis dohrnii)

Beautiful photo of a male Immortal Jellyfish
Meet the remarkable Immortal Jellyfish, capable of defying death and rejuvenating its own cells.

Prepare to be amazed by the remarkable abilities of the Immortal Jellyfish. The Immortal Jellyfish or Benjamin Button Jellyfish, is a remarkable species that has captured the fascination of scientists and nature enthusiasts alike. What makes this jellyfish truly extraordinary is its unique ability to revert its cells back to their earliest form, essentially reversing the aging process and enabling it to achieve potential immortality. Its existence challenges our understanding of mortality and opens up new avenues for exploring the possibilities of extending human lifespan.

Scientific Name Turritopsis dohrnii
Common Names Immortal Jellyfish, Benjamin Button Jellyfish
Natural Habitat Oceans worldwide
Size Length - up to 0.18 inches (0.5 cm), Bell size - very small, less than 0.1 inch (0.3 cm) in diameter
Venomous Rating Non-Venomous

Blue Blubber Jellyfish
(Catostylus mosaicus)

A Chunky Blue Blubber Jellyfish photo taken on night dive
Drifting peacefully, the Blue Blubber Jellyfish graces the sea with its captivating blue hue.

The Blue Blubber Jellyfish is characterized by its dome-shaped bell, which can reach sizes of up to 16 inches (40 cm) in diameter. It possesses short, stout tentacles that fringe the edge of its bell, often with a delicate, frilly appearance. Despite its large size, its mild venomous sting poses minimal threat to humans, making it a fascinating yet harmless presence.

Scientific Name Catostylus mosaicus
Common Names Blue Blubber Jellyfish, Blue Jellyfish
Natural Habitat Indo-Pacific region
Size Length - up to 16 inches (40 cm), Bell size - up to 12 inches (30 cm) in diameter
Venomous Rating Low

The most dangerous jellyfish species

To ensure the safety of beachgoers, swimmers, snorkelers, and scuba divers, it is crucial to understand the distinction between different jellyfish species. We have created an informative infographic highlighting some of the most dangerous types of jellyfish, allowing you to recognize and be prepared for potential encounters.

Dangerous Types of Jellyfish Infographic
Take a moment to study the infographic and enhance your knowledge of these fascinating yet potentially hazardous jellyfish.

How to protect yourself from stinging jellyfish

While jellyfish may captivate us with their ethereal grace, their stings can range from mildly irritating to potentially dangerous. By adopting these preventive measures, you can enjoy your time in the water while minimizing the risks associated with these captivating yet potentially hazardous sea creatures.

Protective Clothing: Wear lightweight, full-coverage clothing such as rash guards or snorkel wetsuits to reduce exposed skin and minimize the chances of jellyfish stings.

Be Informed: Familiarize yourself with the types of jellyfish that inhabit the area where you will be swimming or engaging in water activities. Understand their habits, preferred habitats, and peak seasons to be more aware of potential encounters.

Stay Alert: Keep an eye out for signs, warnings, or flag systems indicating jellyfish activity in the area. If you notice jellyfish in the water, consider avoiding swimming until they have cleared out.

Respect Their Space: Avoid touching or approaching jellyfish, even if they appear to be inactive or washed up on the beach. Some species can still sting even when stranded.

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1 comment

thank you for this page, I absolutely LOVEEEE jellyfish and this expands my hobby to the next level also thanks for giving me a warning for the jelly fish 4 years to late lol😂😂. I was stung in 2020 all around my legs. safe to say im not going back to that beach any time soon

Gabriella February 26, 2024

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