Creature Feature – Immortal Jellyfish

This week’s featured creature is the Immortal Jellyfish. Perfectly coinciding with World Jellyfish Day, today we take a detailed look at one of the most well-known species of jellyfish, the so-called immortal jellyfish. Despite having no brains, no heart and no blood, jellyfish have survived for more than 500 million years – even predating dinosaurs! And this species has a particularly special ability. 


Scientific Name: Turritopsis dohrnii

Phylum: Cnidaria

Order: Anthoathecata

Family: Oceaniidae

Genus: Turritopsis

Immortal Jellyfish Fact File

? Size: Individuals are bell-shaped and have a maximum diameter of about 4.5 millimetres 

? Distribution: This species is believed to have originated in the Pacific, but has since spread all over the world through trans-Arctic migrations, and has speciated into several populations

? Diet: A carnivorous species, their diet mainly consists of plankton, fish eggs and small molluscs

? Behaviour: Whilst most jellyfish species have a relatively fixed lifespan, the ‘immortal jellyfish’ is the only species known to possess the ability to return to a polyp (the other stage of their lifecycle) state, through a specific transformation process.  This ability is unique in the animal kingdom and allows the species to bypass biological death, potentially enabling it to be immortal. However, this does not stop it being eaten by predators or succumbing to disease

? IUCN Status: Not Evaluated. However, many species of Jellyfish are listed as vulnerable (population trend decreasing)