Turritopsis

Turritopsis is a genus of hydrozoans in the family Oceaniidae.

==Species== According to the World Register of Marine Species, this genus includes the following species: Turritopsis chevalense – species inquirenda Turritopsis dohrnii also known as the "Benjamin Button jellyfish", or the "immortal jellyfish". It can reverse its life cycle and transform itself back to a polyp. Turritopsis fascicularis Turritopsis lata Turritopsis minor Turritopsis nutricula (several species, including the "immortal jellyfish", were formerly classified as T. nutricula) Turritopsis pacifica Turritopsis pleurostoma – species inquirenda Turritopsis polycirrha Turritopsis rubra