Nearly immortal sea creature spreads

Hydrozoan with reversible life cycle now found worldwide.

A jellyfish-like hydrozoan with a novel power to rewind its life cycle has been spreading rapidly around the world’s oceans without anyone taking much notice, researchers say.

HIDDEN INVADER Small but pervasive, this jellyfish-like hydrozoan takes several forms. It can survive tough times by collapsing into a blob and then growing back into its youthful, stalklike form.