Details
Turritopsis dohrnii
The immortal jellyfish is a tiny jellyfish famous for reverting from adult medusa to young polyp under stress. In the sea it is a transparent predator of minute animals.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It occurs in Palearctic, Atlantic, and Pacific waters from coasts to open sea. Its life cycle includes drifting medusae and attached polyps on hard surfaces.
Bell diameter 0.4-0.5 cm; weight 0.05-0.2 g. The clear bell shows a small red stomach, with fine tentacles around the edge. Its minute size makes it easy to miss.
Cathemeral and solitary, it drifts with water movement. Under injury or starvation it can reorganize tissues and return to a polyp-like stage.
A carnivore, it catches tiny zooplankton and small crustaceans with stinging cells. Tentacles move subdued prey to the mouth.
Sexual reproduction produces larvae that settle as polyps. Polyps bud off medusae, and stressed adults may reverse back into the polyp stage.
It is listed as Least Concern. Its name is memorable, but individuals can still die from predation, disease, or unsuitable conditions.
