Let's forget we ever read this

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."

[From 'Immortal' jellyfish swarming across the world - Telegraph]