For centuries, man has been on a quest to find the elixir to eternal life. Alchemists struggled fruitlessly to create the legendary philosopher’s stone — a mythical substance capable of turning base metals into precious gold, and said to hold the key to immortality.

But perhaps they were going about it the wrong way. Instead of searching for answers on land, maybe they should have been looking to the sea.

In the seaside town of Shirahama, in Japan, one man thinks he knows what holds the key to everlasting life — jellyfish.

Shin Kubota is a professor at Kyoto University’s Seto Marine Biological Laboratory. He began studying the gelatinous sea creatures in 1979 but there’s one type with which he’s particularly preoccupied — the scarlet jellyfish.

“They don’t die,” Kubota says, “they rejuvenate.” He adds that they are one of three jellyfish species in japan that are considered “immortal.”

“One day in my plankton net there was a small scarlet jellyfish from [the] south, which had many sharp sticks stuck into its body,” he recalls. “I thought ‘poor thing,’ and removed all of the sticks, hoping it may become better and swim again. But it didn’t and shrunk. However, it rejuvenated!”

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It’s less immortality and more regeneration but Kubota believes these tiny marine animals could hold the secret to perpetual life.

When an adult scarlet jellyfish — or medusa — is injured it goes to the bottom of the ocean floor. From there it morphs back into its infant state, known as a polyp. Then the polyp becomes a brand new medusa, allowing the Jellyfish to move between an adult and infant state in about two months.

So far, Kubota has succeeded in making one jellyfish rejuvenate an incredible 12 times in the lab. But there remain many unanswered questions.

“There should be a key to rejuvenation in the system of scarlet jellyfish,” says Kubota. “I’d like to believe it could be applied to human beings because genetically jellyfish and humans are not so different.”

Watch the video below to see more about Kubota’s work at the Seto Marine Biological Laboratory and Japan’s “immortal” jellyfish.