Fascinating and potentially scary story..
The Turritopsis Nutricula is able to revert back to a juvenile form once it mates after becoming sexually mature.
Marine biologists say the jellyfish numbers are rocketing because they need not die.
Dr Maria Miglietta of the Smithsonian Tropical Marine Institute said: "We are looking at a worldwide silent invasion."
The jellyfish are originally from the Caribbean but have spready all over the world.
Turritopsis Nutricula is technically known as a hydrozoan and is the only known animal that is capable of reverting completely to its younger self.
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