Immortal Jellyfish

Immortal Jellyfish, Ele Willoughby (c) 2015, 11" x 14" (27.9 cm x 35.6 cm)

This hand-printed linocut of the Turritopsis dohrnii is the only known animal to be able to revert to its younger colonial stage after having reached maturity - that is the full-grown T. dohrnii jellyfish medusa, if it gets stressed, or old and sick, can revert back to the polyp stage, form a new polyp colony and start all over. So in theory, the jellyfish can bypass death and this cycle can go on forever. The jellyfish is "biologically immortal"! In the real world, there are diseases and predators which interfere with the T. dohrnii's plans of immortality, of course... but unlike the rest of us, it's not an impossible jellyfish dream.

T. dohrnii are hydrozoans which begin life as a sort of free floating fertilized egg known as planula larvae, a sort of plankton. These settle on the seafloor and a colony of polyps, or hydroids, attached to the seafloor like a little garden of multi-branched soon-to-be-jellyfish. The jellyfish, or medusae, bud off these polyps, each a genetically identical clone to the next. The medusae swim freely until sexual maturity. After that, should the T. dohrnii face environmental stress, assault or simply age and illness, it can revert to the polyp form, found a new colony and begin again! This cycle can, in theory, repeat ad infinitum.

The "immortal jellyfish" was formerly classified as T. nutricula, which had also been confused with the similar T. rubra. It turns out that it's quite the challenge to tell one Turritopsis from another. Currently only one scientist, Shin Kubota from Kyoto University, has managed to sustain a group of these jellyfish for a prolonged period of time in captivity; in two years, his colony rebirthed itself 11 times! Wanting to avoid the mistake of confusing one Turritopsis for another, I was glad to read the New York Times Magazine profile of Shin Kubota and the Turritopsis dohrnii - so I could be confident their images were of the right animal!

Incidentally, googling "immortal jellyfish" turns up a lot of strange things, including harebrained anti-aging schemes and vampire fans.