21 Crown Jellyfish Facts You’ll Never Forget

Crown jellyfish facts are filled with interesting information and related details.

Crown jellyfish (Cephea cephea) are found in the Atlantic and Indo-Pacific oceans. They mostly live in deep-sea waters, in the twilight zone, during the day and they come to the open surface during the night. They prefer cold and dark waters and they are also found in bays, estuaries, and lagoons. Sometimes they are found washed up by the sea onto beaches.

This species of jellies has a bell-like structure, which is purple in color. The bell has several grooves which makes it look like a crown. They derive their name from this but the purpose behind these grooves is unknown. This species of jellyfish is transparent, with a reddish-brown belly present underneath the bell. They also have bioluminescent properties with which they can light themselves when touched. This light also helps them dazzle any predators. Crowned jellyfish feed on shrimp, fish, zooplankton, and algae. The average length of life is about six months for this species of jellyfish.

The diameter of its bell is around 23.6 in (60 cm), and the length of each of its eight arms is around 31.5 in (80 cm). Its mouth opening has cilia surrounding it. Crown jellyfish have six different known families and these marine life forms are extremely venomous but they don't pose any threats to humans. They sometimes even help small fish by letting them hide under their hood. Crown jellyfish enemies are often dazzled by the light that these creatures can produce when touched, but they also use their arms to tackle predators.

If you like this article, then check out these other related articles about monkfish and the rainbow trout.

Crown Jellyfish

Fact File

What do they prey on?

Shrimp, zooplankton, fish

What do they eat?


Average litter size?


How much do they weigh?

0.7-14.1 oz (20-400 g)

How long are they?

The bell-shaped structure: 23.6 in (60 cm)

Tentacle: 31.5 in (80 cm)

How tall are they?


What do they look like?

Purple and reddish-brown

Skin Type

Smooth skin

What are their main threats?

Sea anemones, sharks, sea turtles

What is their conservation status?

Least Concern

Where you'll find them

Deep-sea, estuaries, bays, lagoons


The Atlantic Ocean and the Indo-Pacific Ocean





Scientific Name

Cephea cephea


Atollidae, Atorellidae, Linuchidae, Nausithoidae, Paraphyllinidae, Periphyllidae



Crown Jellyfish Interesting Facts

What type of animal is a crown jellyfish?

The crown jellyfish is a kind of jellyfish.

What class of animal does a crown jellyfish belong to?

Crown jellyfish belong to the class called Scyphozoa.

How many crown jellyfish are there in the world?

The exact number of crown jellyfish (Cephea cephea) in the world has not been listed.

Where does a crown jellyfish live?

Crowned jellyfish (Cephea cephea) live in the Atlantic Ocean and the Indo Pacific Ocean. They are found in the twilight zone, at a depth of 656.1-3280.8 ft (200-1000 m) below the surface.

What is a crown jellyfish's habitat?

The crown jellyfish range map extends from the Atlantic Ocean to the Indo-Pacific Ocean. The preferred crown jellyfish habitat is in deep water. These jellies live underwater at cold temperatures during the day and they come to the surface during the night. They are often found in estuaries, bays, and lagoons. Sometimes they are also spotted on beaches.

Who do crown jellyfish live with?

The species of crown jellyfish is known to be a solitary one, like most members of the phylum Cnidaria.

How long does a crown jellyfish live?

The lifespan of crown jellyfish is rather short. They live for around six months on average.

How do they reproduce?

Crown jellyfish reproduction consists of three stages. In the first stage, the adult crown jellyfish releases eggs into the water. The eggs that are released into the ocean water form planula in the second stage. A planula is the larval stage of cnidarian species. The larvae have cilia all around their bodies and during this time they starve, which can last for a month. There is no specific season for the reproduction process as it takes place all year long. The larvae directly transform into the medusae stage in stage three and the polyp stage is next among these bioluminescent crown jellyfish. When they hit a firm surface, they can form polyps. The polyp has the shape of a cup and they have tentacles that surround the opening of their mouths, called orifices. The polyp stage can last for several months and the polyps take part in the process of budding, during which they transform into jellyfish. The bioluminescent crown jellyfish takes part in asexual reproduction.

What is their conservation status?

This crown-shaped sea creature jellyfish is given the status of Least Concern by the IUCN Red List. Due to the abundance of their population and the fact that they face no major threats no conservation measures have been undertaken for them.

Crown Jellyfish Fun Facts

What do crown jellyfish look like?

The crown jellyfish, bioluminescent in nature, is beautiful to look at. These creatures have a purple umbrella-like structure. The bell structure is somewhat transparent in nature. As a result, the reddish-brown belly beneath the umbrella is exposed. The bell structure has grooves surrounding it. There can be up to 30 of these grooves and they make the umbrella resemble a crown. This is the reason behind the creature's name. The purpose behind these grooves is unknown and there are 30 filaments present surrounding the bell. These filaments contain stinging cells, called nematocysts.

They also have a sensory organ called the rhopalium. These occur in a specific pattern in which after every three tentacles, they have one rhopalium. Crown jellyfish have no brain, gills, or blood in their body. They are known to use their tentacles (arms surrounding their mouth) to find their food.

Facts on crowned jellyfish are packed with new and related information that are engrossing to read.
* Please note that this is an image of a jellyfish, not a crown jellyfish specifically. If you have an image of a crown jellyfish please let us know at

How cute are they?

The species of crowned jellyfish (Cephea cephea) is adorable to look at. Their bell-like structure with a groove in it gives them a majestic appearance since the ridges make the bell resemble a crown. In addition to that, the purple color, which is often considered the color of royalty, adds to their cute look! The arms surrounding the orifice also contribute to the cuteness factor of these marine life forms.

How do they communicate?

Crown jellyfish do not communicate like other animals. These marine animals do not have a brain. They use their bioluminescence to attract prey and crowned jellyfish are known to communicate with each other using chemical signals.

How big is a crown jellyfish?

The diameter of their bell-shaped structure is around 23.6 in (60 cm) on average, whereas the length of the tentacles of this deep-sea jellyfish species is around 31.5 in (80cm). They are bigger than the immortal jellyfish.

How fast can a crown jellyfish swim?

The speed of this deep-sea species of jellyfish is around 4.6 mph (7.4 kph).

How much does a crown jellyfish weigh?

Crowned jellyfish (Cephea cephea) can weigh around 0.7-14.1 oz (20-400 g).

What are their male and female names of the species?

No specific names have been given to the male and female species of this deep-sea animal.

What would you call a baby crown jellyfish?

A baby-crowned jellyfish is called ephyrae.

What do they eat?

The species of crowned jellyfish eats shrimp, zooplankton, fish, algae, and invertebrate eggs.

Are they dangerous?

Crowned jellyfish are one of the most venomous jellyfish species to other marine animals. However, they are not harmful to humans

Would they make a good pet?

This Indo-Pacific species of jellyfish is not fit to be kept as pets, just like Irukandji jellyfish. These jellies live in the deep sea and require a cold temperature of around 44.6 F (7 C).

Did you know...

Crown jellyfish are also known by the name crowned jellyfish and they like to live in cold and deep water habitats that are devoid of light during the day. During the night they are found on the open surface of water bodies.

This life form has a transparent bell-like structure that has several grooves in it. From the transparent bell, eight arms descend which are 31.5 in (80 cm) in length. Their mouth opening has cilia surrounding it.

Pink crown jellyfish (Hawaii) and red crown bioluminescent jellyfish are some of the main types of crown jellyfish species.

The crown jellyfish ecological status plays an important role to help maintain the biodiversity of the marine family.

How does a crown jellyfish reproduce?

Crown jellyfish reproduce in three interesting stages. These cold-water marine species of jellyfish have an incredibly fast growth rate, so within three weeks they can grow significantly.

What survival mechanisms do crown jellyfish have?

This species of crowned jellyfish has venomous arms which they use to catch prey. They can also distract or startle their predators in different ways, using light under the dark water and using their tentacles (which are an impressive size and are able to help protect them quite well).

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover!  For more relatable content, check out these longhorn cowfish facts and rockfish facts for kids.

You can even occupy yourself at home by coloring in one of our free printable jellyfish coloring pages.



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