The Immortal Jellyfish

The immortal jellyfish, also known as Turritopis dohrnii, was discovered in 1883. However, this age reversal wasn’t discovered until the 1980s entirely by accident when scientists were monitoring their life cycle. It is a part of the invertebrate phylum of animals known as Cnidaria. However, unlike genuine jellyfish, which are part of the class Scyphozoa, the immortal jelly belongs to the class Hydrozoa. They are incredibly small, about the size of your pinkie nail, and can have up to 90 tentacles as an adult, although the exact number is thought to depend on the location of the jellies, which live all over the world.

As previously mentioned, the immortal jelly is virtually immortal. It can still die due to predators, like sea turtles, penguins, sea anemones, sea slugs, and a plethora of other creatures, as well as habitat destruction and other major harmful events. They aren’t only prey, they also happen to be carnivorous, eating everything from fish eggs to zooplankton to small mollusks. They capture this prey in different ways. One way is by using their venom to paralyze their prey, then eating it. Another is expanding their bells, or their semi circle shaped tops, and using the negative pressure to pull in their prey.

Immortal jellies aren’t just part of the ocean ecosystem. Scientists are currently studying them to see if their regenerative skills can be of use in modern medicine, specifically through the use of transdifferentiation to change cells from one type to another. For example, Dr. Srivastava of UCSF was able to transdifferentiate fibroblasts into cells that behaved like cardiomyocyte cells, which would be helpful in cardiac medicine.