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 (Thorneley, 1904) – species inquirenda
 * Turritopsis dohrnii (Weismann, 1883) 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 Fraser, 1943
 * Turritopsis lata Lendenfeld, 1884
 * Turritopsis minor (Nutting, 1905)
 * Turritopsis nutricula McCrady, 1857 (several species, including the "immortal jellyfish", were formerly classified as T. nutricula)
 * Turritopsis pacifica Maas, 1909
 * Turritopsis pleurostoma (Péron & Lesueur, 1809) – species inquirenda
 * Turritopsis polycirrha (Keferstein, 1862)
 * Turritopsis rubra Farquhar, 1895