Immortal jellyfish

Some reach only slightly beyond 250 years, while others may persist for thousands or even tens of thousands of years.

The freshwater planarian Schmidtea mediterranea and the jellyfish Turritopsis dohrnii are even considered potentially immortal.

Rather than looking only at why certain species live longer than others, the authors compared two dimensions of longevity: variation within exceptionally long-lived species and variation between long- and shorter-lived species.

Their analysis covered genetic, genomic, transcriptomic, proteomic and metabolomic findings as well as telomere maintenance, stress resistance, regeneration and tumorigenesis.

Comparative genomic studies have also identified longevity-associated pathways involved in apoptosis, protein homeostasis, oxidative stress resistance and responses to environmental damage.

Regeneration appears particularly important in some of the most unusual long-lived organisms.

Hydra can regularly replace its cells, while Turritopsis dohrnii can reverse to an earlier developmental stage.

Planarian stem cells, known as neoblasts, can generate multiple cell types and support extraordinary regenerative capacity.

My kids loved Wild Kratts.

That show actually destroyed our family animal guessing game on road trips because my husband and I just couldn't compete with things like Immortal Jellyfish.

They learned a lot on that show.

Now for a few quick headlines before we land.

Yeah, that would work.

So this is commonly called the immortal jellyfish.

It's tiny, smaller than a fingernail.

And most animals have a one-way life cycle.