is a hydrozoan
with a life cycle in which it reverts back to the polyp
stage after becoming sexually mature
. It is the only known case of a metazoan
capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage . It does this through the cell development process of transdifferentiation
. Theoretically, this cycle can repeat indefinitely, rendering it effectively immortal
has a diameter of 4-5 millimeters. It has an equally high and bell-shaped figure. The walls are uniformly thin. The bright red, big stomach has a cruciform shape in its cross section. Young specimens have only eight tentacles along the edge, while adult specimens have 80-90 tentacles.
The fertilized eggs develop in the stomach and in the screen formed by the cave in the jellyfish Planula. The eggs are then planted on the seabed in polyp colonies. The jellyfish hatches after two days. The jellyfish becomes sexually mature after a few weeks (the exact duration depends on the ocean temperature; at 20°C it is 25 to 30 days and at 22°C it is 18 to 22 days).
Jellyfish usually die after propagating, however the Turritopsis nutricula
has developed the ability to return to a polyp state. This is done through a cell change in the external screen (Exumbrella). The ability to reverse the life cycle is unique in the animal kingdom, and allows the jellyfish to bypass death, rendering the Turritopsis nutricula
are found in temperate to tropical regions in all of the world's oceans.