During recent expeditions by NOAA's Okeanos Explorer, the team came across this extraordinary jellyfish, belonging to the genus Crossota. Check out how beautiful it is quietly pulsing its way through the ocean:

The hypnotic beauty of this jellyfish certainly got us curious about other unique and beautiful jellyfish species found throughout the world's oceans. Here are nine more gorgeous and alien-looking species.

Cauliflower jellyfish

The cauliflower jelly is more beautiful and strange than its name suggests. The cauliflower jelly is more beautiful and strange than its name suggests. (Photo: J'nel/Shutterstock)

The cauliflower jelly is named for the wart-like projections on its bell, which resemble the vegetable. While that doesn’t sound very pretty, the species itself is beautiful.

Found in the mid-Pacific to the Indo-Pacific, and also in the Atlantic ocean off of West Africa, the cauliflower jelly is an oceanic species that can grow relatively large, reaching diameters of 1.5 to 1.9 feet.

Much like its vegetable namesake, it is something you can find on dinner plates. Well, in China and Japan, anyway. The species is considered a delicacy and also is utilized for medicinal purposes.

Cephea cephea is a crown jelly, and is also known as a cauliflower jelly. Cephea cephea is a crown jelly and is also known as a cauliflower jelly. (Photo: Dray van Beeck/Shutterstock)

Crystal jellyfish

The crystal jelly is translucent like glass in sunlight. The crystal jelly is translucent like glass in sunlight. (Photo: MattStansfield/iStockPhoto)

In the waters off North America’s west coast lives the crystal jellyfish, a species that is completely colorless and has up to 150 delicate tentacles lining its glass-like bell.

This gorgeous jellyfish species looks crystal clear in daylight. But the transparency belies a brighter side.

According to Monterey Bay Aquarium, "Crystal jellies are brightly luminescent jellies, with glowing points around the margin of the umbrella. The components required for bioluminescence include a Calcium++ activated photoprotein, called aequorin, that emits a blue-green light, and an accessory green fluorescent protein (GFP), which accepts energy from aequorin and re-emits it as green light. Scientists have created 'green mice' that glow green when hit by blue light by inserting the GFP gene from the crystal jelly into the mice. The glowing protein is a widely used biological highlighter that helps scientists find and study genes more quickly."

In the dark, crystal jellies show off their bioluminescence. In the dark, crystal jellies show off their bioluminescence. (Photo: Gary Kavanagh/iStockPhoto)

White-spotted jellyfish

Though beautiful, the white-spotted jellyfish can be a troublesome invasive species where it has been introduced. The venom of the white-spotted jellyfish is very weak, and it is a filter feeder. (Photo: MattiaATH/Shutterstock)

White-spotted jellies are one species you don’t have to fear. The mild venom isn’t a problem for humans. These filter feeders are more focused on minuscule zooplankton, and an individual can filter as much as 13,000 gallons of water a day in its quest for a meal.

The downside of this is a swarm of white-spotted jellies can clear an area of zooplankton, leaving none for the fish and crustaceans that also make a meal of the microscopic critters. In areas where they are considered an invasive species, such as the Gulf of California, Gulf of Mexico and Caribbean Sea, their voracious appetite poses a problem for native species from corals to crustaceans such as shrimp.

Though beautiful, the white-spotted jellyfish can be a troublesome invasive species where it has been introduced. Though beautiful, the white-spotted jellyfish can be a troublesome invasive species where it has been introduced. (Photo: Vladimir Wrangel/Shutterstock)

Bloodybelly comb jellyfish

This species wins the contest for the coolest common name. Or at least it ranks way up there. This one you really need to see in action with the sparkling light show it puts on. Be sure to watch through to the end where it opens up like a spaceship coming out of the abyss.

Technically, though, the bloodbelly comb jelly isn’t even related to jellyfish. They do not have the famous stinging tentacles and are harmless to humans. But what they lack in tentacles they make up for in cilia, tiny hair-like projections they beat back and forth to swim through the water. It is the movement of this cilia that creates the colorful light show.

Despite looking a bit like a show-off, the bloodbelly comb jelly’s red color actually makes it nearly invisible in the deep water where they’re found. Red looks basically black in such depths. The red belly may also help to mask the bioluminescent glow of the prey the comb jelly eats, keeping it extra safe from the attention of predators.

Black sea nettle

Black sea nettles are so called because of their dark coloration. Black sea nettles are so called because of their dark coloration. (Photo: Sean Lema/Shutterstock)

Another red denizen of the deep is the black sea nettle. This species, found in the deep water of the Pacific from southern California to Baja California, is a giant among jellyfish. Its bell can reach three feet across, its arms can be 20 feet long and its stinging tentacles 25 feet long. It would be pretty scary to find yourself in the middle of a bloom.

Though enormous, the species is relatively new to science and not well known. Part of this is because they’re very difficult to raise in captivity, and they aren’t often encountered in the wild. There have been a few surface blooms of black sea nettles, with the invertebrate giants appearing in large numbers in 1989, 1999 and 2010. Other than these blooms, where black sea nettles hang out and what they're up to is still a bit of a mystery.

Flower hat jellyfish

The flower-hat jelly has an unusual reproductive cycle that was a mystery to science until 2012. The flower hat jelly has an unusual reproductive cycle that was a mystery to science until 2012. (Photo: Glenn Young/Shutterstock)

This extraordinarily colorful and odd species is endemic to the Western Pacific, primarily off the coast of Southern Japan, but it is also found in waters off of Brazil and Argentina. Rather than pulsing their way through the ocean, flower hat jellyfish often hang out near the ocean floor among sea grasses where they catch prey of small fish.

They may look gorgeous, but you don't want to get close. They pack a nasty sting. According to Monterey Bay Aquarium, “Blooms of the flower hat jellies make swimming in waters off Argentina hazardous. The sting of this jelly is painful, leaving a bright rash. In Brazil, blooms of the flower hat jellies interfere with shrimp fishing; the jellies clog their nets and drive shrimp away, probably to deeper water.”

This species is dotted with beautifully fluorescent coloring. This species is dotted with beautifully fluorescent coloring. (Photo: Ginn Tinn Photography/Shutterstock)

Mediterranean or fried egg jellyfish

There are two species of jellyfish that resemble eggs broken open in the ocean. This one is cotylorhiza tuberculata. There are two species of jellyfish that resemble eggs broken open in the ocean. This one is cotylorhiza tuberculata. (Photo: Rich Carey/Shutterstock)

We’ll give you one guess at how this species got its common name. Cotylorhiza tuberculata is better known as the fried egg jellyfish or the Mediterranean jellyfish. The bell of the jellyfish is surrounded by a lighter ring, which forms something of a moat, and combined the bell looks very much like a favorite breakfast food.

The species is also called the Mediterranean jelly and is commonly found in the Mediterranean Sea, Aegean Sea and Adriatic Sea. The species is also called the Mediterranean jelly and is commonly found in the Mediterranean Sea, Aegean Sea and Adriatic Sea. (Photo: EloyMR/Shutterstock)

The mouth-arms of the fried egg jellyfish are truncated, and there are longer projections with disk-like ends. The overall effect makes it look dotted with purple and white pebbles. This species only survives for about six months, from summer to winter, dying when the water cools down.

Tiny fish can take shelter under the bell of this species. Tiny fish can take shelter under the bell of this species. (Photo: Vilainecrevette/Shutterstock)

The species feeds on zooplankton, rather than fish. Something that smaller fish appreciate. As you can see from the above photo, juvenile fish can hide inside the fried egg jellyfish’s tentacles for protection. Sometimes small species of crabs will hitch a ride on the bell.

Atolla jellyfish

The Atolla jellyfish, also called Coronate medusa, is a deep-sea jelly found around the world. Like many species of animals dwelling in the deep, it has bioluminescent abilities. But unlike many species that use bioluminescence to attract prey, this species uses it to keep from becoming prey.

When an Atolla jellyfish is attacked, it will create a series of flashes that spin like the lights of a police siren, as shown in the video above. This draws in more predators that will hopefully be interested in the original attacker more than the jellyfish, giving the jellyfish opportunity to escape.

This strategy has given the species the nickname the “alarm jellyfish.”

Narcomedusae

The deep-sea hydrozoan jellyfish Bathykorus bouilloni has a distinctly Darth Vader-like appearance. The deep-sea hydrozoan jellyfish Bathykorus bouilloni has a distinctly Darth Vader-like appearance. (Photo: Kevin Raskoff/Wikipedia)

It's Darth Vader! Oh, wait... That's just a Narcomedusae. This unusual looking species of jellyfish has not one but two stomach pouches. To fill those pouches with plenty of prey, it will hold its long tentacles out in front of it while it swims. Researchers think this makes them a more effective ambush predator.

According to Creature Cast, “Some species of Narcomedusae (affectionately called narcos by the people that study them) can grow inside their own mother, who provides nourishment and a safe environment for her. The narco babies can then leave their mother, find another jellyfish of an entirely different species, attach to its flesh, and thrive on the nourishment and safe environment it provides."

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.