Nature’s Fireworks: We Discover the Flower Hat Jelly Life Cycle

Some things are worth waiting for – even if it takes 12 years.

Our jelly biologists have discovered the elusive life cycle of Olindias formosus – the stunning flower hat jelly, whose multicolored, fluorescent-tipped tentacles are like a living fireworks show.

The flower hat jelly was first discovered in waters off Japan over 100 years ago, but its life cycle was a mystery. Biologists around the world have been eager to exhibit this gorgeous jelly, but were unable to culture it to adulthood. Now, after 12 years of research, we solved the mystery, and you can see them in The Jellies Experience special exhibition.

“We’re thrilled to discover the life cycle of the flower hat jelly,” said Senior Aquarist Wyatt Patry. “Our team succeeded through collaboration, diligence and a bit of good luck.”

Our discovery could lead to predicting dangerous jelly “blooms” in the wild. The flower hat jelly packs a powerful sting, enabling it to kill and eat fish – and harm humans. Blooms of hundreds or thousands of these jellies off Japan and Brazil have resulted in injuries to many beachgoers, and at least one death, Patry said.

About the Flower Hat Jelly

Found in coastal waters off southern Japan, Brazil and Argentina, and in the Mediterranean, the flower hat jelly has brilliant tentacles trailing from its translucent, pinstriped bell. Another set of curly tentacles under its bell can quickly unfurl and grab prey. This nocturnal species swims in the water column at night and attaches itself to the seafloor during the day.

Our work to understand the life cycle of this mysterious jelly began in 2002 during the Jellies: Living Art special exhibition, which ran from 2002 to 2008. That team was the first to successfully exhibit flower hat jellies in the United States, and culture fertilized eggs and larvae – another first.

Shining a Light on an Amazing Life Cycle

Patry said the current team’s initial breakthrough occurred with a redesigned exhibit that let flower hat jellies capture and eat live fish and kept them away from debris on the bottom. Patry said the team hoped those conditions would encourage successful reproduction – and they did.

Special blue lighting in the exhibit was the next breakthrough. The flower hat jellies, which are fluorescent, are in a gallery that interprets three different types of “lights” in certain jellies – fluorescence, bioluminescence and diffraction. About six months after putting a batch of flower hat jellies on exhibit, Patry noticed two previously unseen stages of their life cycle – polyps and tiny baby jellies.

“I was only able to see them because they are fluorescent, like the adults,” Patry said. “From there we worked with the polyps to refine the ideal food and temperature requirements for them to produce more babies.”

Still have your first ticket to the Aquarium? We do! This week’s #ThrowbackThursday features our first-ever printed tickets, including one to our Grand Opening in 1984. We’re celebrating 30 years—help us reach our future goals

Still have your first ticket to the Aquarium? We do! This week’s #ThrowbackThursday features our first-ever printed tickets, including one to our Grand Opening in 1984.

We’re celebrating 30 years—help us reach our future goals

Music and molas? Evenings by the Bay starts this weekend! We’re open until 8 p.m. on Saturdays and Sundays so you can see the Aquarium in a whole new light. Learn more

Music and molas? Evenings by the Bay starts this weekend! We’re open until 8 p.m. on Saturdays and Sundays so you can see the Aquarium in a whole new light. 

Learn more

Remember hearing about Juno, the rescued pup that was reared behind the scenes by our exhibit otter, Ivy? Looks like she’s thriving at her new home at the Oregon Zoo!

Learn how we’re helping save sea otters

(Shervin Hess/Oregon Zoo)

Will fish and other #ocean animals get left high and dry? Learn more in our latest podcast.  

Where do you find inspiration? First as a volunteer and now as an assistant aquarist, Michelle Stamme loves working with our eight-armed animals—and painting them!

Share your love of #MBATentacles and you could win!

Want to help our oceans? Just “Think Big!” Join us for a musical performance with dazzling puppets made from recycled materials. Sing along as a sea turtle, Laysan albatross and brave sardine work to protect their home—and learn how you can help!

Plan your visit

Learn more about our innovative puppets

How do we collect and display amazing deep-sea cephalopods for our Tentacles exhibit? It takes a big boat, a remote-controlled robot, and help from our colleagues at the Monterey Bay Aquarium Research Institute!

Learn more about the flapjack octopus and the cock-eyed squid.

(Jonathan Wolf photos)

Hacking for Healthy Oceans

For 36 hours over Father’s Day Weekend, the Aquarium hosted an unusual sleepover. Few of the participants got much rest.

We were one of five sites for a first-ever State Department-sponsored Fishackathon. The goal was to find technological solutions so fishermen in the developing world can make their catch more sustainable.

Teams of coders, designers and project managers created website solutions and apps for smartphones and cell phones - tools that small-scale fishermen can use in places like West Africa and the Philippines to document their catch and report illegal fishing.

Nearly 40 participants gathered on a Friday night in Monterey with laptops, sleeping bags - and novel ideas for creating tools that will be effective in parts of the world where internet access and high-tech equipment is limited. By Sunday morning, they had solutions to offer.

In addition to tackling two State Department problem statements, we also asked our hackers to help with a Seafood Watch challenge: How can information about how fish were caught travel through the supply chain from the boat where it’s landed to the market or restaurant where it’s finally sold?

The outcome? Incredible.

The results were beyond our wildest expectations.

A four-person team we welcomed from the UC-Berkeley School of Information won the top national prize for “Fish DB”, a multi-layered solution to one of the State Department challenges. And a three-person team that formed during the Fishackathon won the Seafood Watch challenge with its “Go Fish!” app: a simple labeling system using colors and numbers to show sustainability and freshness of seafood items. The app incorporates gaming principles, rewards and social sharing features to encourage consumers to buy ocean-friendly seafood.

"I can’t believe what great results these teams produced over the weekend!" said Jennifer Dianto Kemmerly, director of Seafood Watch. "We will definitely tap into the talents of hackers in the future."

An appealing location

It might not be too hard to lure them back to Monterey, if comments from the Berkeley team are any indication. They used words like “epic” and “thrilled” to describe sleeping in front of the Kelp Forest and Open Sea, and having access to the knowledge of Aquarium staff and State Department experts.

“We had a blast!” team member Isha Dandavate told the UC-Berkeley news service. “I can’t even express how cool it was. Having the hackathon in an aquarium has sort of ruined us for all other hackathons.”

The State Department was equally thrilled, and is now making plans for a 2015 Fishackathon around World Oceans Day.

Learn how your everyday choices can support healthy oceans

And that’s how they roll! Some cephalopods lumber along the seafloor, while others use jet propulsion. These cool creatures are part of our Tentacles exhibit.

Share YOUR love of cephalopods at #MBATentacles and you could win!

About me

The Monterey Bay Aquarium, perched on the edge of a world-famous coastline, is your window to the wonders of the ocean. It’s located on historic Cannery Row in Monterey and is open daily except Christmas Day.

For more information about our animals and exhibits, and to view our live web cams, please visit

Hours of operation vary by season. Daily schedules and tickets are available on our website or by calling
(831) 648-4800.