The life span of most species is from 2 to 6 months. An interesting species of jellyfish Turritopsis nutricula, which has rare abilities to rejuvenate itself indefinitely, has been discovered. Usually jellyfish after mating die, but the jellyfish Turritopsis nutricula returns to its stage, which is very similar to the stage at birth. This unique feature makes the jellyfish immortal.
Another interesting feature of these creatures is their ability to restore lost parts of the body – absolutely all cells of these animals are interchangeable: even if this animal is divided into parts, it will restore them, thus forming two new individuals! If this is done with an adult jellyfish, an adult copy will appear, a larva from the larva of the jellyfish.
The life span of the hydroid jellyfish with a metagenetic development cycle in plankton is often several months. The life expectancy of small jellyfish does not exceed 2-3 months, but little is known about scyphoid jellyfish. Pelagia and Aurelia, seem to live no more than a year.