16 Types Of Jellyfish to Learn About

Gently undulating through the waves, jellyfish seem almost out of place in our world. But looks can be deceiving. Some types of jellyfish contain enough venom to kill a human being.

Jellyfish come in all shapes and sizes, from those found near coastlines that are smaller than a grape to deep sea creatures that can be as large as blue whales!

With such biodiversity, there’s a lot to learn about jellyfish. We’ve gathered the web’s most extensive resource on jellyfish below, including interesting species and must-know facts. Read on to learn more about these different types of jellyfish.

1. Nomura Jellyfish

The Nomura jellyfish is one of the heftiest species of jellyfish, often capable of ballooning up to six feet (1.82 m) in diameter and lugging around 400 pounds (181.43 kg).

These guys primarily occupy the waters between China and Japan but have been known to create destructive blooms elsewhere that deplete fish populations.

The population of Nomura jellyfish has exploded in recent years, to the point where they now present a danger to China and Japan. In order to understand why this species grows so large, and how best to reduce their numbers, special research teams have been formed.

These scientists believes that the Nomura jellyfish are able to grow larger than normal because of a combination of hydroelectric projects and farming along the Yangtze river.

These two factors have created enriched nutrient habitats in the Sea of Japan, which provides an ideal environment for these creatures to thrive.

Although it should be easy to remove jellyfish blooms from the water, Nomura jellyfish have a special defense mechanism. When they feel threatened, they release billions of sperm and eggs which attach to the ocean floor and grow into more jellyfish.

2. Bloody-Belly Comb Jellyfish

The Bloodybelly Comb jellies are next on our list of the most amazing and beautiful jellyfish. Although they’re technically classified as comb jellies, they only have a distant relation to actual jellyfish.

The Comb jelly is not like other jellyfish that sting humans; it is actually harmless.

Though they don’t have tentacles, cilia more than make up for it. Cilia are tiny hair-like projections that help beat back and forth to propel the animal through water by creating resistance. This movement also creates a sparkling light show consisting of an array of different colors.

The Bloodybelly Comb jellies are normally found in deep water, and despite their red color, this actually makes them nearly invisible.

Underwater, black and red tend to look similar. More specifically, the bloody belly of this comb jellyfish helps it avoid notice by predators who would be drawn to its prey’s bioluminescent glow.

3. Lion’s Mane Jellyfish

The lion’s mane jellyfish is one of the largest types of jellyfish, with some specimens coming close to the size of a blue whale. 

The biggest recorded lion’s mane jellyfish had a seven-foot (2.13 m) diameter bell and 112 feet (34.13 m) long tentacles. Their name comes from the approximately 1,200 tentacles that make up their mane. 

Lion’s mane jellyfish are mostly found floating in the open ocean in the Arctic and North Pacific Oceans. Lion’s mane jellyfish are bioluminescent and have tentacles covered in millions of stinging cells, holding venom that can be very painful to humans. But since they’re mostly found in cold water, lion’s mane jellyfish don’t normally interact with humans.

4. Upside-Down Jellyfish

While most jellyfish float through the ocean with their bell facing up, upside-down jellyfish have their bells on the ground instead. Their tentacles are extended upwards to catch food more easily. You can find these type of jellyfish close to coasts near tropical areas worldwide.

trapping food and predators! The upside-down jellyfish has a one of a kind way to protect itself which by releasing mucus that contains nematocysts into the water; Consequently, its able to hunt prey.

A single upside-down jellyfish boasts a venom that isn’t too harsh, but when one creatures releases envenomated mucus, the rest of its colony does as well. This spell trouble for small fish swimming in nearby waters.

People who have snorkeled through these waters have said they felt a stinging sensation. This is most likely because of the upside-down jellyfish’s mucus.

5. Moon Jellyfish

The moon jellyfish is the most commonly found type of jellyfish, and they can be in any ocean except for the Arctic.

Moon jellyfish are safe for humans to touch because their stings can’t penetrate our skin. They’re a popular species of fish kept in aquariums because of this, but also due to the half circles on their bells which are reproductive tissues.

Moon jellyfish are bioluminescent, glowing a light purple when bumped in the dark. They’re also one of the species most commonly eaten by people.

6. Crystal Jellyfish

Crystal jellyfish are found in the Pacific Ocean from the Bering Sea to Southern California. These nearly transparent, ethereal-looking creatures can grow up to ten inches (25.4 cm) in diameter, with long tentacles that seem to float in the water like string.

When crystal jellyfish are untouched, they appear nearly transparent. However, if you were to prod one of them, you would see that they emit a green-blue light. Similarly, scientists often utilize the bioluminescent cells from these jellyfish as genetic markers in their studies.

Crystal jellyfish are opportunistic predators, feeding on anything up to half their size that they can fit into their mouths. However, this makes them a common target for larger animals such as ocean sunfish. Another threat to crystal jellyfish comes from an unlikely source- plastic bags and other trash frequently mistaken for thereal thing by these creatures.

7. Deep Red Jellyfish

The deep red jellyfish is relatively unknown due to the difficulty of accessing their natural habitat. These creatures are found living at depths of 3,000 feet or more in the Arctic Sea. They grow to a much smaller size than other species of jellyfish, with a diameter averaging only two centimeters (0.78 inches).

The deep red jellyfish is unique among other species because it doesn’t go through a polyp phase, and its method of reproduction is unknown. It’s strange appearance has led scientists to describe it as alien-like.

8. Four-Handed Box Jellyfish

The four-handed box jellyfish is found in the West Atlantic Ocean, Gulf of Mexico, and the Pacific Ocean. This Jellyfish is nearly transparent and has a bell about the size of a human fist with tentacles that can grow up to 13 feet long (3.96 m). 

The four-handed box jellyfish is incredibly dangerous because of its venom. In some cases, the sting has killed people within minutes, and it can be lethal to small children.

9. Sea Wasp Jellyfish

The sea wasp jellyfish is a large cubozoan jellyfish found in the coastal waters of Australia and Southeast Asia. It has a bell of approximately eight inches (20.32 cm) and tentacles up to ten feet long (3.04 m).

The sea wasp jellyfish is not only the most venomous of its species, but also produces the strongest and fastest reaction of any venomous animal. Once the tentacles come into contact with an unsuspecting victim, immediate pain sets it, followed by cardiac failure which leads to death within minutes.

The venom sea wasps produce is better at catching prey than it is warding off predators, so these creatures are often eaten by larger ocean animals such as leatherback turtles. 

Scientists are researching why the venom of the sea wasp jellyfish is so powerful. They have found a special component in the venom that drills holes in red blood cells. Researchers believe they can produce an antidote for this venom through clinical trials.

10. Immortal Jellyfish

The immortal jellyfish is incredibly small, no larger than a pinky nail. Its stomach is visible in the center of its bell-like shape and it is transparent all around.

The Turritopsis dohrnii jellyfish is found in all types of warm waters around the world. People have given this species the name “immortal” because it never dies–or at least, not as we know death. After living through the medusae phase, most jellyfish would die.

However, instead of dying, the Turritopsis dohrnii settles on Seafloor and becomes polyps again. From there, they create new clones of the original jellyfish.

Not only does this life cycle quirk present itself during the natural end of their lives, but it is also employed as a defense mechanism. When threatened by predators or starvation, the jellyfish transforms back into a polyp and starts over again. This cellular process is called transdifferentiation and scientists are researching its potential applications in medicine.

11. Mangrove Box Jellyfish

The mangrove box jellyfish, which is native to Central America, lives on the seafloor in coastal mangrove forests. They are relatively small animals; their bells (the main body) are about the size of a grape, and their tentacles only grow to about an inch in length.

Although they resemble and are related to the sea wasp, mangrove box jellyfish venom is not harmful to people. However, these animals are facing habitat loss as a result of deforestation; mangrove forests happen to be one of the most threatened ecosystems globally.

The mangrove box jellyfish is being forced out of its natural habitat due to the destruction of mangrove forests for agricultural and commercial purposes.

12. Black Sea Nettle

Because they’re deep-sea dwellers and difficult to raise in captivity, little is known about black sea nettles. These giant jellyfish have bells reaching over three feet (0.91 m) in diameter and tentacles up to twenty-five feet (7.62 m) long!

Dangerous blooms of these creatures have been found in San Diego Bay, and they are typically seen near the southern coast of California and down Mexico’s Pacific Coast.

The mutually beneficial relationship between black sea nettles and Pacific butterfish has been observed: the butterfish eat the plankton gathered by the black sea nettle and hide inside the jellyfish’s bell when necessary for safety.

13. Fried Egg Jellyfish

The fried egg jellyfish derives its namesake from the yellow circle donning their bell. They are also called Mediterranean jellyfish and have a lifespan of only six months, from summer to winter. Colder water temperatures signal their death.

The size of a giggling beach ball, these jellyfish are found frolicking in the Mediterranean, Aegean, and Adriatic Seas.

They have a gentle sting that is mostly harmless to people but can be bothersome if you’re unlucky enough to come into contact with one. These good samaritans have been known to give small animals like crabs rides on their bell or even house them inside their translucent bodies.

14. Cauliflower Jellyfish

Crown jellyfish, also known as cauliflower jellyfish, are found in tropical oceans across the world. They can grow up to seven inches (17.78 cm) in diameter and are one of the most venomous types of jellyfish. However, their venom is not harmful to humans.

Cauliflower jellyfish are not stationary; they move vertically in the ocean, spending more time deeper during the day and coming nearer to the surface at night.

When predators come close, these jellyfish will light up due to bioluminescence. Furthermore, cauliflower jellyfish are consumed as food by people in Japan and China and have even been used medicinally.

15. Atolla Jellyfish

Atolla jellyfish are found worldwide in the depths of the ocean, living 3,280-13,000 feet (999.74 – 3,962.4 m) below the surface in what is known as the midnight zone. These creatures use bioluminescence to disorient predators rather than attract prey.

The atolla jellyfish has a bell diameter of about six inches (15.24 cm). Their natural red coloring allows them to blend in and act as camouflage in the deep sea. If they feel threatened, they use bioluminescence to flash a bright blue and startle predators.

16. White-Spotted Jellyfish

White-spotted jellyfish are mostly found in tropical waters near the western Pacific Ocean. They obtain their name from the white spots observed on their bell and tentacles. Even though they carry venom, it is not poisonous to humans and they don’t use it for feeding purposes. These types of jellyfish eat microscopic zooplankton after filtering it first.

White-spotted jellyfish form blooms that can ruin local ecosystems by clearing all the plankton from the water. These types of jellyfish become invasive species in areas without marine snails, which are their most natural predator.

Interesting Jellyfish Facts

• Did you know that approximately 50% of jellyfish species can glow? Glowing in the dark is a defence mechanism used by these types of jellyfish against predators. Some use bioluminescent flashes to startle potential danger, while others produce chains of light or release glowing particles into their watery habitat to confuse would-be predators. The majority of luminescent jellyfish are found deep sea dwelling, but some like the moon jellyfish reside closer to the surface and have even been spotted by swimmers in natural waters before!
• A group of jellyfish is called a smack, and multiple smacks are known as blooms.
• Jellyfish have a very simplified internal organs compared to other invertebrates. In fact, they don’t even have brains, hearts or eyes. All they consist of is a mouth and stomach for their digestive system.
• Some scientists believe that jellyfish lived even before dinosaurs roamed the earth. In 2007, a perfectly preserved fossil of a jellyfish was discovered in Utah. It is thought to be over 505 million years old! The oldest dinosaur fossils are about 230 million years old, which means that the first jellyfish existed way before their time. This also suggests that they might be the planet’s oldest multicellular animal.
• In 1991, an experiment was done to see how jellyfish would react in a space environment without gravity. Polyps were sent into space, which produced medusa jellyfish. The results showed that the jellyfish coped well enough without gravity but their functions changed and they didn’t perform as well when brought back to Earth’s gravity levels.
• Jellyfish are made up of 5% structural proteins, muscles, and nerve cells. For comparison, humans are 60% water.