Updated at: 06-10-2023 - By: petstutorial

Jellyfish are fascinating creatures that spend their lives floating in the oceans. There are over 200 known species of jellyfish, each unique in color, size, and behavior.

Jellyfish belong to the order Cnidaria, which also includes other marine creatures like corals. They capture their prey and defend themselves using their tentacles, which have stinging cells. The jellyfish sting occurs when the stinging cells, triggered by touch, eject tiny venomous barbs into the skin of a predator or prey.

In this article, we will explore nine different types of jellyfish, from graceful moon jellies to fearsome box jellyfish, and reveal the mysterious characteristics that make these creatures so fascinating.


9 Types Of Jellyfish

Box Jellyfish

Box jellyfish, also known as sea wasps or marine stingers, are highly advanced among jellyfish. They have developed the ability to move rather than just drift, jetting at up to four knots through the water. Some key characteristics and facts about box jellyfish include:

Physical Characteristics:
– Box-shaped bell with a diameter ranging from 1 to 30 cm (0.4 to 11.8 inches).
– Pale blue and transparent in color, with up to 60 tentacles in four clumps along the base of the bell.
– Each tentacle can reach up to 10 feet in length and contains about 5,000 stinging cells (nematocysts).

Venom and Diet:
– Box jellyfish developed their powerful venom to instantly stun or kill prey, such as fish and shrimp, without damaging their delicate tentacles.
– They capture prey by touching them with their long tentacles and stinging them with their nematocysts before swallowing them.
– Their venom can cause paralysis, cardiac arrest, and even death in humans and animals.

Habitat and Distribution:
– Box jellyfish are found in warm coastal waters around the world, with the most venomous species primarily located in the Indo-Pacific region and northern Australia.
– They are often found in the tropical waters of the Indo-Pacific region, including Northern Australia.

– Reproduction and Lifespan:
– Box jellyfish can mate using internal fertilization, and after males deposit sperm packets inside a female’s bell, fertilized eggs develop as planulae (free-swimming egg-shaped larvae).
– They have a relatively short lifespan, rarely living past nine months of age.

Unique Features:
– Box jellyfish have 24 eyes arranged in clusters around their bell, a feature unique among cnidarians.
– They can use their vision for navigation and to avoid stationary structures, and some of their eyes have a sophisticated lens, retina, iris, and cornea.
– Unlike most jellyfish, which float with the current, box jellyfish are strong enough to swim against it to pursue and capture prey.

Moon Jellyfish


Moon jellyfish, also known as Aurelia labiata, are small, translucent invertebrates that inhabit the northeast Pacific Ocean and frequent the waters of the Salish Sea. Some key characteristics and facts about moon jellyfish include:

Physical Characteristics:
– Translucent, moon-like bell with a 16-scalloped margin and four opaque half-circles on the top, resembling a four-leaf clover without the stem.
– Relatively small, growing to about 3 inches in length and having almost no weight.
– Thin and short tentacles that extend around the circumference of the bell, unlike most jellyfish with long trailing tentacles.

Habitat and Distribution:
– Moon jellyfish are found in oceans around the world, preferring warm environments and often living near coastlines in the Atlantic, Pacific, and Indian oceans.
– They can live in saltwater or brackish (mixed salt- and freshwater) environments, with waters between 45 and 70 degrees Fahrenheit offering them the best chance of survival.

Diet and Hunting Technique:
– Moon jellyfish feed on fish eggs and larvae, zooplankton, small crustaceans, and cladocerans, known as water fleas.
– They have a passive hunting technique, floating through the water and relying on the current until they come across prey. They stretch out their stinging tentacles, usually spreading out wide rather than up and down, to capture their food.

Reproduction and Lifespan:
– Moon jellyfish have a short lifespan, usually emerging in early spring, then spawning and dying by late summer or early fall.
– Young moon jellyfish, called polyps, tend to attach to the undersides of docks, where they can avoid predators and have ample room to grow. Millions of polyps can be attached to the underside of a dock at one time.

Population and Conservation:
– Moon jellyfish populations can increase in environments experiencing human-induced phenomena like overfishing, ocean warming, ocean acidification, and pollution.
– While this species is not threatened, its presence can serve as an indicator that marine ecosystems are out of balance.

Cauliflower Jellyfish

Cephea cephea, also known as the crown jellyfish or cauliflower jellyfish, is a species of jellyfish in the family Cepheidae. It is found in the tropical waters of the western Indo-Pacific to Northern Australia. Some key characteristics and facts about cauliflower jellyfish include:

Physical Characteristics:
– The cauliflower jellyfish has a unique, flat, and soft mushroom-like bell that resembles a cauliflower.
– It is translucent and gelatinous, with tentacles armed with stinging cells.
– The species can achieve a diameter of up to 60 cm.

Habitat and Distribution:
– Cauliflower jellyfish are found in the pelagic zone of tropical and sub-tropical waters and are most commonly found in the Indo-West Pacific, eastern Atlantic, and the Red Sea.
– They live and thrive in cold water and can be found as deep as over 3,000 feet below the surface.
– The species is bioluminescent, meaning it can produce light.

Diet and Hunting Technique:
– The cauliflower jellyfish’s prey mainly consists of algae, shrimp, plankton, invertebrate eggs, and invertebrate larvae.

Venom and Harm to Humans:
– Although this species is among the most venomous jellyfish, its stings and venom are not harmful to humans.
– In fact, cauliflower jellyfish are eaten as a delicacy and used for medical purposes in China and Japan.

Cauliflower jellyfish are fascinating creatures with a unique appearance and interesting characteristics. They play an important role in the marine ecosystem and continue to intrigue scientists and researchers with their behavior and biology.

Lion’s Mane Jellyfish


The lion’s mane jellyfish, also known as Cyanea capillata, is a fascinating and unique creature found in the Arctic, Northern Atlantic, and Northern Pacific Oceans. Here are some key characteristics and facts about the lion’s mane jellyfish:

Size and Appearance:
– The lion’s mane jellyfish is one of the largest jellyfish species, with some individuals having tentacles up to 120 feet long and a bell 8 feet in diameter.
– Its bell-shaped body is characterized by eight lobes and can range in color from light orange to dark crimson.
– The jellyfish’s long, hair-like tentacles hanging from the underside of its bell are the inspiration behind its common name, “lion’s mane”.

Habitat and Distribution:
– Most lion’s mane jellyfish live in the Arctic and North Pacific Ocean, from Alaska to Washington, where the waters are cool.
– They are also found in the Northern Atlantic, from Western to Southern Scandinavia, the English Channel, the Irish Sea, and the North Sea.

Diet and Predators:
– Lion’s mane jellyfish have a limited diet that consists of small fish, other smaller jellyfish, ctenophores (comb jellies), zooplankton, and crustaceans.
– Common predators of the lion’s mane jellyfish include other jellyfish, ocean sunfish, sea turtles (which are not affected by the jellyfish’s neurotoxins), and larger fishes.

Behavior and Reproduction:
– Lion’s mane jellyfish are continual swimmers that can cover great distances when strong marine currents are present.
– While most individuals prefer to swim solo, large swarms occasionally occur when storms and tides are prevalent.
– The jellyfish breeds in March and early May through external fertilization.
– It has a relatively short lifespan of about one year, during which it hatches, grows, reproduces, and dies.

Human Interaction and Conservation:
– The lion’s mane jellyfish has a powerful sting, but reports of human fatalities are few.
– Scientific research has suggested that jellyfish, including the lion’s mane species, thrive in areas affected by human activity, such as overfishing, climate change, and pollution.
– These factors have created a favorable environment for the species, with few known threats to its population.

Portuguese Man-of-War

The Portuguese man o’ war, also known as the man-of-war, is a marine hydrozoan found in the Atlantic Ocean and the Indian Ocean. It is considered to be the same species as the Pacific man o’ war or bluebottle, which is found mainly in the Pacific Ocean. Here are some key characteristics of the Portuguese man o’ war:

– Not a jellyfish: The Portuguese man o’ war is often mistaken for a jellyfish, but it is actually a siphonophore, a group of animals closely related to jellyfish. It is a colonial organism, made up of many smaller units called zooids, which work together as one.

– Venomous: The Portuguese man o’ war has numerous venomous microscopic nematocysts in its tentacles, which deliver a painful sting powerful enough to kill fish and occasionally humans. Its sting is rarely deadly to people, but it can cause welts on exposed skin.

– Carnivorous: The Portuguese man o’ war is a carnivore that feeds on small adult fish, fish fry (young fish), zooplankton, shrimp, and other small crustaceans. It uses its venomous tentacles to trap and paralyze its prey while “reeling” it inwards to the digestive polyps.

– Floating and Propulsion: The Portuguese man o’ war is a neuston, a community of organisms that live at the ocean surface. It is propelled by winds and ocean currents alone and sometimes floats in legions of 1,000 or more. The man o’ war’s float, which may be blue, violet, or pink, rises up to six inches above the waterline and resembles an 18th-century Portuguese warship under full sail.

– Reproduction: Each individual Portuguese man o’ war is either a male or a female, and they reproduce sexually via a method known as broadcast spawning. Large groups of individuals come together, where females release their eggs and males release their sperm into the water column, all at the same time, increasing the likelihood of fertilization.

Flower Hat Jellyfish


The flower hat jelly, also known as Olindias formosus, is a unique and striking species of hydromedusa in the hydrozoan family Olindiidae. Here are some key characteristics and facts about the flower hat jelly:

– The flower hat jelly has a translucent bell with pinstriped opaque bands, and its tentacles are brilliantly multicolored, often coiling and adhering to its rim when not in use.
– It can grow to be about 15 cm (6 in) in diameter, but when first observed in the wild, it typically measures only 2 cm (0.8 in).

Habitat and Distribution:
– Flower hat jellies are found in the northwestern Pacific, specifically off central and southern Japan and South Korea’s Jeju Island.
– Close relatives of the flower hat jelly, such as O. sambaquiensis, are found off Argentina and Brazil.

Behavior and Diet:
– These jellies typically live near the ocean floor, close to kelp or seagrass, and during the day, they rest on the bottom, often among rocks or algae.
– At night, they float up to hunt for their prey, which primarily consists of small fish and some marine invertebrates.

Venom and Human Interaction:
– The sting of the flower hat jelly is generally mildly painful and can leave a rash.
– There is a single known human fatality from Japan.

Life Cycle and Reproduction:
– The adult form of the flower hat jelly only lives a few months and is typically seen from December to July, with peaks in April and May.
– Little is known about the details of its life cycle, but flower hat jellies have been bred in displays at the Monterey Bay Aquarium, where the hydroids attached themselves to various surfaces and formed small clusters before releasing the medusae.

Mauve Stingers


The mauve stinger, scientifically known as Pelagia noctiluca, is a jellyfish in the family Pelagiidae and the only recognized species in the genus Pelagia. Here are some key characteristics and facts about the mauve stinger:

– The mauve stinger has a partially translucent to yellowish body dotted with pale pink to purple coloration.
– It has a maximum bell size of around 12 cm (4.5 in) and four oral arms, which look like thick, patterned tentacles used to transport prey to the mouth.

Habitat and Distribution:
– Mauve stingers are mostly found in the North Atlantic and Mediterranean, but they can also be found in the North Sea, as far north as Canada, and in warmer waters closer to the equator, such as the Gulf of Mexico.
– They inhabit open ocean areas but can sometimes be found near shores.

Behavior and Diet:
– During the day, mauve stingers linger in deep waters, and at night, they move to shallower waters to feed on plankton.
– They have long tentacles and warty structures on their bell, which are filled with stinging cells used to capture prey.

Venom and Human Interaction:
– The sting of the mauve stinger can cause pain, local redness, swelling, and a rash, but it is generally not dangerous, and there are no known fatalities.
– In rare cases, the sting can cause a serious allergic reaction and leave scars or hyperpigmented marks on the skin that can remain for years.

– The mauve stinger’s name in German means “night light,” referring to its reddish coloring and bioluminescence.
– When startled, it can leave a trail of glowing mucus behind, which has been studied by scientists to understand gene expression and protein production.

Crystal Jellyfish


The crystal jellyfish, also known as Aequorea victoria, is a bioluminescent hydrozoan jellyfish found off the west coast of North America. Here are some key characteristics and facts about the crystal jellyfish:

– The crystal jellyfish is almost entirely transparent and colorless, with a highly contractile mouth and manubrium at the center of up to 100 radial canals that extend to the bell margin.
– The bell margin is surrounded by uneven tentacles, up to 150 of them in fully-grown specimens, which possess nematocysts that aid in prey capture.

Habitat and Distribution:
– Crystal jellyfish are found in the Pacific waters off the coast of North America, from the Bering Sea to southern California.
– They typically live in cooler waters and can be found in the Washington state and British Columbia areas.

Behavior and Diet:
– Crystal jellyfish feed on copepods but sometimes may consume ctenophores and other jellyfish.
– They can expand their mouth when feeding to swallow jellies more than half their size.

Venom and Human Interaction:
– The crystal jellyfish’s sting is not harmful to humans.

– The crystal jellyfish is best known as the source of aequorin, a photoprotein, and green fluorescent protein (GFP), two proteins involved in bioluminescence.
– When startled, it can leave a trail of glowing mucus behind, which has been studied by scientists to understand gene expression and protein production.

The crystal jellyfish is a fascinating creature with unique characteristics and behavior. It plays an important role in the marine ecosystem and continues to intrigue scientists and researchers with its bioluminescence and biology.

Upside-Down Jellyfish

The upside-down jellyfish, also known as Cassiopea, is a unique species of jellyfish that spends most of its time resting on its back over the sediment, giving it an upside-down appearance. Here are some key characteristics and facts about the upside-down jellyfish:

– The upside-down jellyfish has a flattened bell that allows it to rest on sediment, with its oral arms extending upwards.
– The bell continuously pulses to push water over the jellyfish’s tissue, providing it with oxygen and bringing food.
– The jellyfish’s eight oral arms are branched, splayed out, and typically green, grey, or blue in color, due to a photosynthetic algae called zooxanthellae that lives inside the jellyfish’s tissue.

Habitat and Distribution:
– Upside-down jellyfish are usually found in sheltered coastal areas such as lakes, lagoons, or estuaries and are often associated with areas surrounded by mangroves.
– They typically occur in shallow water that is less than a meter deep so that there is enough sunlight for the zooxanthellae in their tissues.
– The species is found in warmer coastal regions around the world, including shallow mangrove swamps, mudflats, canals, and turtle grass flats in Florida, the Caribbean, Micronesia, and the Gulf of Mexico.

Behavior and Diet:
– The upside-down jellyfish feeds on zooplankton, which it catches with its tentacles.
– It is capable of swimming, using regular contractions of the bell to push it through the water.
– These jellyfish partake in a symbiotic relationship with photosynthetic dinoflagellates and therefore, must lie upside-down in areas with sufficient light penetration to fuel their energy source.

Venom and Human Interaction:
– The sting of the upside-down jellyfish is generally not harmful to humans, but it can cause mild pain, rash, and swelling.

The upside-down jellyfish is a fascinating creature with unique characteristics and behavior. It plays an important role in the marine ecosystem and continues to intrigue scientists and researchers with its biology.


1. What are the different types of jellyfish mentioned in the article?

The article covers the following types of jellyfish: Box Jellyfish, Moon Jellyfish, Cauliflower Jellyfish, Lion’s Mane Jellyfish, Portuguese Man-of-War, Flower Hat Jellyfish, Mauve Stingers, Crystal Jellyfish, and Upside-Down Jellyfish.

2. Where can these jellyfish be found?

The distribution of these jellyfish varies, but they can be found in various oceans and coastal regions around the world. Specific habitats and locations are mentioned in the respective sections of the article.

3. Are these jellyfish dangerous to humans?

Some of these jellyfish have stings that can be harmful to humans, while others have milder stings or are not harmful at all. The level of danger depends on the species and individual circumstances.

4. What do these jellyfish eat?

The diet of these jellyfish varies, with some feeding on small fish and plankton, while others consume other jellyfish or even have a symbiotic relationship with photosynthetic organisms.

5. Can these jellyfish be kept as pets?

Some of these jellyfish can be kept in specialized aquariums, but they require specific care and conditions. It is important to research the specific needs of each species before considering them as pets.

6. Do these jellyfish have any unique characteristics or behaviors?

Yes, each jellyfish species has its own unique characteristics and behaviors, which are discussed in the respective sections of the article.

7. Are these jellyfish endangered?

The conservation status of these jellyfish varies, with some species being more vulnerable to environmental changes and human activities than others. It is important to promote responsible and sustainable practices to protect these creatures and their habitats.

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